SEC Form DEF 14A filed by Trevi Therapeutics Inc.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934

(Amendment No. )

Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐

Check the appropriate box:

TREVI THERAPEUTICS, INC.

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check all boxes that apply):

TREVI THERAPEUTICS, INC.

195 Church Street, 16th Floor

New Haven, CT 06510

NOTICE OF 2025 ANNUAL MEETING OF STOCKHOLDERS

To be held June 11, 2025

You are cordially invited to attend the 2025 Annual Meeting of Stockholders of Trevi Therapeutics, Inc. The Annual Meeting is scheduled to be held exclusively online via the Internet as a virtual web conference at www.virtualshareholdermeeting.com/TRVI2025 on Wednesday, June 11, 2025 at 1:00 p.m. Eastern Time.

Only stockholders who owned common stock at the close of business on April 15, 2025, the record date for the Annual Meeting, can vote at the Annual Meeting or any adjournment or postponement that may take place. At the Annual Meeting, the stockholders will consider and vote on the following matters:

A complete list of registered stockholders as of the close of business on April 15, 2025, the record date for the Annual Meeting, will be available for examination by any stockholder for any purpose germane to the Annual Meeting for a period of ten days ending on the day before the Annual Meeting at www.virtualshareholdermeeting.com/TRVI2025.

As noted above, our Annual Meeting will be a “virtual meeting” of stockholders, which will be conducted exclusively via the Internet. There will not be a physical meeting location and stockholders will not be able to attend the Annual Meeting in person. However, you may attend the Annual Meeting online, vote your shares electronically during the meeting and submit questions during the meeting by visiting www.virtualshareholdermeeting.com/TRVI2025.

In order to attend the Annual Meeting online, vote your shares and submit your questions electronically during the Annual Meeting, you must visit www.virtualshareholdermeeting.com/TRVI2025 on June 11, 2025 at 1:00 p.m. Eastern Time. Further information about how to attend the Annual Meeting online, vote your shares and submit questions is included in the accompanying proxy statement. As outlined in the accompanying proxy statement, the Board of Directors recommends that you vote in favor of each director nominee in proposal one, in favor of proposals two, three and five and in favor of a frequency of holding future advisory votes to approve the compensation paid to our named executive officers every year in proposal four.

You can find more information, including the nominees for director, in the accompanying proxy statement for the Annual Meeting, which is also available for viewing, printing and downloading at www.proxyvote.com.

Instead of mailing to our stockholders a printed copy of our proxy materials, including the accompanying proxy statement, the proxy card and our annual report to stockholders for the fiscal year ended December 31, 2024, we provide access to these materials via the Internet. This reduces the amount of paper necessary to produce these materials as well as the costs associated with mailing these materials to all stockholders. Accordingly, on or about April 28, 2025, we plan to mail a Notice of Internet Availability of Proxy Materials, or Notice, to all stockholders of record at the close of business on April 15, 2025, the record

date for the Annual Meeting, and we will post our proxy materials on the website referenced in the Notice. As more fully described in the Notice, stockholders may choose to access our proxy materials on the website referred to in the Notice or may request to receive a printed or e-mailed set of our proxy materials. In addition, the Notice and website provide information regarding how you may request to receive proxy materials in printed form by mail, or electronically by email, on an ongoing basis.

If you are a stockholder of record, you may vote or submit a proxy to vote in one of the following ways:

If your shares are held in “street name,” that is, held for your account by a bank, broker or other nominee, you will receive instructions from the bank, broker or other nominee that you must follow for your shares to be voted.

Whether or not you plan to attend the Annual Meeting, we urge you to take the time to submit your proxy to vote your shares.

By order of the Board of Directors,

Trevi Therapeutics, Inc.

Proxy Statement

TREVI THERAPEUTICS, INC.

195 Church Street, 16th Floor

New Haven, CT 06510

203-304-2499

PROXY STATEMENT

FOR THE 2025 ANNUAL MEETING OF STOCKHOLDERS

to be held June 11, 2025

This proxy statement and the proxy card contain information about the 2025 Annual Meeting of Stockholders of Trevi Therapeutics, Inc., or the Annual Meeting, to be held exclusively online via the Internet as a virtual web conference at www.virtualshareholdermeeting.com/TRVI2025 on Wednesday, June 11, 2025 at 1:00 p.m. Eastern Time. You will be able to attend the Annual Meeting online, vote your shares electronically during the meeting and submit questions during the meeting by visiting www.virtualshareholdermeeting.com/TRVI2025. There will not be a physical meeting location and you will not be able to attend the Annual Meeting in person. Your vote is very important to us. Whether or not you plan to attend the Annual Meeting online, your shares should be represented and voted.

The Board of Directors of Trevi is using this proxy statement and the proxy card to solicit proxies for use at the Annual Meeting. In this proxy statement, unless expressly stated otherwise or the context otherwise requires, the use of “Trevi,” “our,” “we” or “us” refers to Trevi Therapeutics, Inc. and its wholly owned subsidiary.

Important Notice Regarding the Availability of Proxy Materials for

the Annual Meeting of Stockholders to be Held on June 11, 2025:

This proxy statement and our 2024 Annual Report to Stockholders are

available for viewing, printing and downloading at www.proxyvote.com.

A copy of our Annual Report on Form 10-K for the fiscal year ended December 31, 2024, as filed with the Securities and Exchange Commission, or SEC, except for exhibits, will be furnished without charge to any stockholder upon written request to Trevi Therapeutics, Inc., 195 Church Street, 16th Floor, New Haven, CT 06510. This proxy statement and our Annual Report on Form 10-K for the fiscal year ended December 31, 2024 are also available on the SEC’s website at https://www.sec.gov.

On or about April 28, 2025, we plan to mail a Notice of Internet Availability of Proxy Materials, or Notice, to all stockholders of record at the close of business on April 15, 2025, the record date for the Annual Meeting, other than to those stockholders who previously requested electronic or paper delivery of proxy materials. The Notice will direct stockholders to a website where they can access our proxy materials, including this proxy statement, the proxy card and our annual report to stockholders for the fiscal year ended December 31, 2024, and view instructions on how to submit a proxy. If you would prefer to receive a paper copy of our proxy materials, please follow the instructions included in the Notice. If you have previously elected to receive our proxy materials electronically, you will continue to receive access to those materials via e-mail unless you elect otherwise.

IMPORTANT INFORMATION ABOUT THE ANNUAL MEETING AND VOTING

Purpose of the Annual Meeting

At the Annual Meeting, our stockholders will consider and vote on the following matters:

As of the date of this proxy statement, we are not aware of any business to come before the Annual Meeting other than the first five items noted above.

Board of Directors Recommendation

Our Board of Directors unanimously recommends that you vote:

FOR the election of the two nominees to serve as Class III directors on our Board of Directors for a three-year term; and

FOR the ratification of the appointment of Ernst & Young LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2025; and

FOR the approval of the compensation paid to our named executive officers; and

FOR the approval of a frequency of one year for holding future advisory votes to approve the compensation paid to our named executive officers; and

FOR the approval of an amendment to the Trevi Therapeutics, Inc. 2019 Stock Incentive Plan to increase the number of shares available for issuance under the plan by 6,000,000 shares of common stock, and make certain other amendments.

Availability of Proxy Materials

We plan to mail the Notice regarding our proxy materials, including this proxy statement, the proxy card and our annual report to stockholders for the fiscal year ended December 31, 2024, to stockholders of record on or about April 28, 2025. Our proxy materials will be available for viewing, printing and downloading on the Internet at www.proxyvote.com.

Information About the Annual Meeting

This year’s Annual Meeting will be conducted as a virtual meeting of stockholders, which will be held exclusively online via the Internet as a virtual web conference. We believe that hosting a virtual meeting will facilitate stockholder attendance and participation at our Annual Meeting by enabling stockholders to participate from any location around the world. You will be able to attend the Annual Meeting online, vote your shares online during the Annual Meeting and submit your questions online during the Annual Meeting by visiting www.virtualshareholdermeeting.com/TRVI2025. There will not be a physical meeting location and you will not be able to attend the Annual Meeting in person. We have designed the virtual Annual Meeting to provide the same rights and opportunities to participate as stockholders have at an in-person meeting, including the right to vote and ask questions through the virtual meeting platform.

The Annual Meeting will start at 1:00 p.m. Eastern Time, on June 11, 2025. Please note that you can only access the Annual Meeting via www.virtualshareholdermeeting.com/TRVI2025 beginning at 12:45 p.m. Eastern Time, on June 11, 2025. Please be sure to follow the instructions found on your proxy card and/or notice. If you encounter any difficulties accessing the Annual Meeting during check-in or at the time of the Annual Meeting, please contact the technical support phone numbers at www.virtualshareholdermeeting.com/TRVI2025.

Who Can Vote at the Annual Meeting

Only stockholders who owned our common stock at the close of business on the record date of April 15, 2025 are entitled to receive notice of the Annual Meeting and to vote the shares of our common stock that they held on that date. As of April 15, 2025, there were 99,892,915 shares of common stock issued and outstanding. Each share of common stock is entitled to one vote on each matter properly brought before the Annual Meeting.

Difference between a “stockholder of record” and a beneficial owner of shares held in “street name”

Stockholder of Record. If your shares are registered directly in your name with our transfer agent, Computershare, then you are considered a “stockholder of record” of those shares. In this case, the Notice has been sent to you directly by us. You may submit a proxy to vote your shares prior to the Annual Meeting by following the instructions contained on such Notice.

Beneficial Owners of Shares Held in "Street Name". If your shares are held by a bank, broker or other nominee, then you are considered the beneficial owner of those shares, which are held in “street name.” In this case, the Notice has been forwarded to you by that organization. The organization holding your account is considered the stockholder of record for purposes of voting at the Annual Meeting. As the beneficial owner, you have the right to instruct that organization as to how to vote the shares held in your account by following the instructions contained on the voting instruction card provided to you by that organization.

How to Vote Your Shares

If you are a stockholder of record, you can vote your shares in one of two ways: either by submitting a proxy or online during the Annual Meeting. If you choose to submit a proxy to vote, you may do so by telephone, via the Internet or by mail. Each of these methods is explained below. If you hold your shares of our common stock in multiple accounts, you should vote or submit a proxy to vote your shares as described in each set of proxy materials you receive.

Stockholders of record will be able to submit a proxy to vote by telephone or the Internet prior to the Annual Meeting up until 11:59 p.m. Eastern Time on June 10, 2025, and mailed proxy cards must be received by June 10, 2025 in order to be counted at the Annual Meeting. If the Annual Meeting is adjourned or postponed, these deadlines may be extended.

If you are the beneficial owner of shares held in “street name”, you can submit instructions to vote those shares by following the instructions contained on the voting instruction card provided to you by the bank, broker or other nominee that holds your shares. If you wish to vote online during the Annual Meeting, you must demonstrate proof of your beneficial ownership to virtually attend the Annual Meeting and obtain a legal proxy from the organization that holds your shares. The voting deadlines and availability of telephone and Internet submission of proxies for beneficial owners of shares held in “street name” will depend on the voting processes of the organization that holds your shares. Therefore, we urge you to carefully review and follow the voting instruction card and any other materials that you receive from that organization.

Shares Held in “Street Name” and “Broker Non-Votes”

If your shares are held in “street name,” your bank, broker or other nominee may under certain circumstances vote your shares even if you do not return voting instructions. Stock exchange rules permit brokers to vote customers’ shares on certain proposals for which they have received no voting instructions. Stock exchange rules, however, prohibit brokers from voting uninstructed shares in the case of the election of directors and certain other matters. Of the matters to be voted on at the Annual Meeting, we expect the only proposal on which your bank, broker or other nominee will have discretionary voting authority to vote your shares in the absence of voting instructions is the ratification of the appointment of Ernst & Young LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2025.

“Broker non-votes” occur when your bank, broker or other nominee submits a proxy for your shares but does not indicate a vote for a particular proposal because the bank, broker or other nominee does not have or did not exercise the authority to vote on that proposal and has not received voting instructions from you.

Quorum

A quorum of stockholders is necessary to hold a valid meeting. Our amended and restated bylaws provide that a quorum will exist if stockholders holding a majority in voting power of the shares of stock issued and outstanding and entitled to vote are present at the meeting in person, by means of remote communication in a manner authorized by the Board of Directors in its sole discretion, or by proxy. If a quorum is not present, the meeting may be adjourned until a quorum is obtained.

For purposes of determining whether a quorum exists, we will count as present any shares that are represented by proxy submitted over the Internet, by telephone or by completing and submitting a proxy by mail, or that are present virtually during the Annual Meeting. Further, for purposes of establishing a quorum, we will count as present shares that a stockholder holds even if the stockholder votes to withhold or abstain or only votes on one of the proposals. In addition, we will count as present shares that are “broker non-votes.”

Votes Required

Proposal No. 1 – Election of Directors

The two nominees for director receiving the highest number of votes “for” election will be elected as Class III directors. This is called a plurality. You may vote “for” all nominees; vote “for” one or more nominees and “withhold” your vote from the other nominees; or “withhold” your vote from all nominees. Shares held in “street name” by your bank, broker or other nominee who indicate on their proxies that they do not have authority to vote the shares on this proposal will not be counted as votes “for” or “withhold” from any director nominee and will be treated as “broker non-votes.” Votes that are withheld and “broker non-votes” will not be included in the vote tally for the election of directors and will not affect the results of the vote.

Proposal No. 2 – Ratification of Appointment of Independent Registered Public Accounting Firm

The ratification of the appointment of Ernst & Young LLP as our independent registered public accounting firm requires the affirmative vote of a majority of the shares of common stock present or represented by proxy and voted “for” or “against” such matter. Abstentions will have no effect on the outcome of this proposal.

Proposal No. 3– Advisory Vote to Approve Executive Compensation

The approval on an advisory basis, of the compensation paid to our named executive officers, requires the affirmative vote of a majority of the shares of common stock present or represented by proxy and voted “for” or “against” such matter. Abstentions and “broker non-votes” will have no effect on the outcome of this proposal. Proposal No. 3 is non-binding. Because this vote is advisory and not binding on us or our Board of Directors in any way, our Board of Directors may decide that it is in our and our stockholders’ best interests to compensate our named executive officers in an amount or manner that differs from that which is approved by our stockholders.

Proposal No. 4– Advisory Vote on the Frequency of Future Advisory Votes to Approve Executive Compensation

The approval on an advisory basis, of one of the frequency options for future advisory votes to approve the compensation paid to our named executive officers, requires the affirmative vote of a majority of the shares of common stock present or represented by proxy and voting on such matter. With respect to this proposal, if none of the frequency options (one year, two years or three years) receives a majority vote, we will consider the frequency that receives the highest number of votes cast by stockholders to be the frequency that has been recommended by stockholders. Abstentions and “broker non-votes” will have no effect on the outcome of this proposal. Proposal No. 4 is non-binding. Because this vote is advisory and not binding on us or our Board of Directors in any way, our Board of Directors may decide that it is in our and our stockholders’ best interests to hold an advisory vote to approve executive compensation more or less frequently than the alternative approved by our stockholders.

Proposal No. 5 – Approval of an Amendment to the Trevi Therapeutics, Inc. 2019 Stock Incentive Plan

The approval of the amendment to the Trevi Therapeutics, Inc. 2019 Stock Incentive Plan to increase the number of shares available for issuance under the plan by 6,000,000 shares of common stock, and make certain other amendments, requires the affirmative vote of a majority of the shares of common stock present or represented by proxy and voted “for” or “against” such matter. Abstentions and “broker non-votes” will have no effect on the outcome of this proposal.

Method of Counting Votes

Each holder of common stock is entitled to one vote at the Annual Meeting on each matter to come before the Annual Meeting, including the election of directors, for each share held by such stockholder as of the record date. Votes cast online during the Annual Meeting or represented by proxy submitted by mail, via the Internet or by telephone prior to the Annual Meeting will be tabulated by the inspector of election appointed for the Annual Meeting, who will also determine whether a quorum is present.

Revoking a Proxy; Changing Your Vote

If you are a stockholder of record, you may revoke your proxy and change your vote by following one of the below procedures:

If your shares are held in “street name,” you may submit new voting instructions with a later date by contacting your bank, broker or other nominee holding your shares. You may also vote via the Internet during the Annual Meeting, which will have the effect of revoking any previously submitted voting instructions, if you demonstrate proof of your beneficial ownership to virtually attend the Annual Meeting and obtain a legal proxy from the organization that holds your shares as described in the “How to Vote Your Shares” section above.

Your attendance online at the Annual Meeting will not automatically revoke your proxy.

Costs of Proxy Solicitation

We will bear the costs of soliciting proxies. In addition to solicitations by mail, our directors, officers and regular employees, without additional remuneration, may solicit proxies by telephone, facsimile, email, personal interviews and other means.

Submitting Questions Online at the Annual Meeting

If you wish to submit a question during the Annual Meeting, you may log into the Annual Meeting platform at www.virtualshareholdermeeting.com/TRVI2025, type your question into the “ask a question field” and click “submit”. Our Annual Meeting will be governed by our Rules of Conduct, which will be posted at 12:45 p.m. on June 11, 2025 at www.virtualshareholdermeeting.com/TRVI2025. The Rules of Conduct will address the ability of stockholders to ask questions during the Annual Meeting, including rules on permissible topics, and rules for how questions and comments will be recognized and disclosed to Annual Meeting participants.

Voting Results

We plan to announce preliminary voting results at the Annual Meeting and will publish final results in a Current Report on Form 8-K to be filed with the SEC within four business days following the Annual Meeting.

PROPOSAL NO. 1—ELECTION OF TWO CLASS III DIRECTORS

Our Board of Directors currently consists of six members. In accordance with the terms of our restated certificate of incorporation and our amended and restated bylaws, our Board of Directors is divided into three classes (Class I, Class II and Class III), with members of each class serving staggered three-year terms. The members of the classes are divided as follows:

Upon the expiration of the term of a class of directors, directors in that class will be eligible to be elected for a new three-year term at the Annual Meeting of Stockholders in the year in which their term expires.

Our restated certificate of incorporation and our amended and restated bylaws provide that the authorized number of directors may be changed only by resolution of our Board of Directors. Our restated certificate of incorporation and amended and restated bylaws also provide that our directors may be removed only for cause by the affirmative vote of the holders of at least 75% of the votes that all our stockholders would be entitled to cast in an annual election of directors and that any vacancy on our Board of Directors, including a vacancy resulting from an enlargement of our Board of Directors, may be filled only by vote of a majority of our directors then in office.

Our Board of Directors has nominated Ms. Jennifer Good and Ms. Anne VanLent for election as Class III directors at the Annual Meeting. Each of the nominees is presently a director and each has indicated a willingness to continue to serve as director, if elected. If a nominee becomes unable or unwilling to serve, however, the proxies may be voted for substitute nominees selected by our Board of Directors.

Nominees for Election as Class III Directors

Biographical information, including principal occupation and business experience during the last five years, for our nominees for election as Class III directors at our Annual Meeting is set forth below.

The Board of Directors recommends voting “FOR” the election of Ms. Good and Ms. VanLent as Class III directors, for a three-year term ending at the Annual Meeting of Stockholders to be held in 2028.

Any properly submitted proxy will be voted in favor of the nominees unless a contrary specification is made in the proxy. The nominees have consented to serve as directors if elected. However, if any nominee is unable to serve or for good cause will not serve

as a director, the persons named in the proxy intend to vote in their discretion for one or more substitutes who will be designated by our Board of Directors.

Directors Continuing in Office

Biographical information, including principal occupation and business experience during the last five years, for our directors continuing in office after the Annual Meeting is set forth below.

Class I Directors (Term Expires at 2026 Annual Meeting)

Class II Directors (Term Expires at 2027 Annual Meeting)

There are no family relationships between or among any of our directors or executive officers. The principal occupation and employment during the past five years of each of our directors was carried on, in each case except as specifically identified above, with a corporation or organization that is not a parent, subsidiary or other affiliate of us. There is no arrangement or understanding between any of our directors and any other person or persons pursuant to which he or she is to be selected as a director.

There are no material legal proceedings to which any of our directors is a party adverse to us or our subsidiary or in which any such person has a material interest adverse to us or our subsidiary.

Executive Officers Who Are Not Directors

Biographical information for our executive officers who are not directors is listed below.

PROPOSAL NO. 2—RATIFICATION OF THE APPOINTMENT OF ERNST & YOUNG LLP

AS OUR INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM FOR THE

FISCAL YEAR ENDING DECEMBER 31, 2025

Our stockholders are being asked to ratify the appointment by the audit committee of the Board of Directors of Ernst & Young LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2025.

The audit committee is solely responsible for selecting our independent registered public accounting firm for the fiscal year ending December 31, 2025. Stockholder approval is not required to appoint Ernst & Young LLP as our independent registered public accounting firm. However, our Board of Directors believes that submitting the appointment of Ernst & Young LLP to the stockholders for ratification is good corporate governance. If the stockholders do not ratify this appointment, the audit committee will reconsider whether to retain Ernst & Young LLP. If the selection of Ernst & Young LLP is ratified, the audit committee, in its discretion, may direct the appointment of a different independent registered public accounting firm at any time it decides that such a change would be in the best interest of our company and our stockholders.

A representative of Ernst & Young LLP is expected to attend the Annual Meeting and will have an opportunity to make a statement if he or she desires to do so and to respond to appropriate questions from our stockholders.

We incurred the following fees from Ernst & Young LLP for the audit of the consolidated financial statements and for other services provided during the years ended December 31, 2024 and 2023.

Audit Committee Pre-Approval Policy and Procedures

The audit committee of our Board of Directors has adopted policies and procedures for the pre-approval of audit and non-audit services for the purpose of maintaining the independence of our independent auditor. We may not engage our independent auditor to render any audit or non-audit service unless either the service is approved in advance by the audit committee, or the engagement to render the service is entered into pursuant to the audit committee’s pre-approval policies and procedures. Notwithstanding the foregoing, pre-approval is not required with respect to the provision of services, other than audit, review or attest services, by the independent auditor if the aggregate amount of all such services is no more than 5% of the total amount paid by us to the independent auditor during the fiscal year in which the services are provided, such services were not recognized by us at the time of the engagement to be non-audit services and such services are promptly brought to the attention of the audit committee and approved prior to completion of the audit by the audit committee or by the chair of the audit committee.

From time to time, our audit committee may pre-approve services that are expected to be provided to us by the independent auditor during the following 12 months. At the time such pre-approval is granted, the audit committee must identify the particular pre-approved services in a sufficient level of detail so that our management will not be called upon to make a judgment as to whether a proposed service fits within the pre-approved services, establish a monetary limit with respect to each particular pre-approved service, which limit shall not be exceeded without obtaining further pre-approval, and, at each regularly scheduled meeting of the audit committee following such approval, management or the independent auditor shall report to the audit committee regarding each service actually provided to us pursuant to such pre-approval. The audit committee has delegated to its chairman the authority to grant pre-approvals of audit or non-audit services to be provided by the independent auditor, provided that the fees for such services do not

exceed $50,000. Any approval of services by the chairman of the audit committee is reported to the committee at its next regularly scheduled meeting.

During our 2024 and 2023 fiscal years, no services were provided to us by Ernst & Young LLP other than in accordance with the pre-approval policies and procedures described above.

The Board of Directors recommends voting “FOR” Proposal No. 2 to ratify the appointment of Ernst & Young LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2025.

Any properly submitted proxy will be voted in favor of the ratification of the appointment of Ernst & Young LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2025 unless a contrary specification is made in the proxy.

PROPOSAL NO. 3—ADVISORY VOTE TO APPROVE EXECUTIVE COMPENSATION

We are providing our stockholders the opportunity to vote to approve, on an advisory, non-binding basis, the compensation of our named executive officers as disclosed in this proxy statement in accordance with the SEC’s rules. This proposal, which is commonly referred to as “say-on-pay,” is required by the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010, or the Dodd-Frank Act, which added Section 14A to the Exchange Act. Section 14A of the Exchange Act also requires that stockholders have the opportunity to cast an advisory vote with respect to whether future advisory votes to approve the compensation paid to our named executive officers will be held every one, two or three years, which is the subject of Proposal No. 4.

Our executive compensation program is designed to attract and retain qualified and talented executives, motivate such executives to achieve our business goals and reward them for short- and long-term performance with a simple and clear compensation structure. Under this program, our named executive officers are rewarded for the achievement of our short- and long-term performance, which we believe serves to enhance short- and long-term value creation for our stockholders. The program contains elements of cash and equity-based compensation and is designed to align the interests of our executives with those of our stockholders.

Our Board of Directors is asking stockholders to approve a non-binding advisory vote on the following resolution:

RESOLVED, that the compensation paid to the Company’s named executive officers, as disclosed pursuant to the compensation disclosure rules of the Securities and Exchange Commission, including the compensation tables, narrative discussion and any related material disclosed in this proxy statement, is hereby approved.

As an advisory vote, this proposal is not binding on our Board of Directors, our compensation committee or the Company. However, our compensation committee and Board of Directors value the opinions expressed by our stockholders in their vote on this proposal and intend to carefully consider the outcome of the vote when making future compensation decisions for named executive officers.

The Board of Directors recommends voting “FOR” the approval, on an advisory basis, of the compensation paid to our named executive officers.

PROPOSAL NO. 4—ADVISORY VOTE ON THE FREQUENCY OF FUTURE ADVISORY VOTES TO APPROVE EXECUTIVE COMPENSATION

In Proposal No. 3, we are providing our stockholders with the opportunity to vote to approve, on an advisory, non-binding basis, the compensation of our named executive officers. In this Proposal No. 4, we are asking our stockholders to cast a non-binding advisory vote regarding the frequency of future advisory votes to approve executive compensation. Stockholders may vote for a frequency of every one, two, or three years, or may abstain. As this is the first year in which we are required to hold an advisory vote to approve executive compensation pursuant to the SEC’s rules, we do not currently have a set frequency for such votes.

Our Board of Directors intends to carefully consider the outcome of this vote in making a determination about the frequency of future advisory votes to approve executive compensation. However, because this vote is advisory and non-binding, our Board of Directors may decide that it is in the best interests of our stockholders and the Company to hold advisory votes to approve executive compensation more or less frequently, but no less frequently than once every three years, as required by the Dodd-Frank Act. In the future, we will propose an advisory vote on the frequency of the advisory votes to approve executive compensation at least once every six calendar years as required by the Dodd-Frank Act and Section 14A of the Exchange Act, as described in Proposal No. 3.

After careful consideration, our Board of Directors believes that an advisory vote to approve executive compensation should be held every year, and therefore our Board of Directors recommends that you vote for a frequency of every year for future advisory votes to approve executive compensation.

Our Board of Directors believes that an annual advisory vote to approve executive compensation will facilitate more direct stockholder feedback about executive compensation. An annual advisory vote to approve executive compensation is consistent with

our policy of reviewing our compensation program annually, as well as seeking input from our stockholders on corporate governance and executive compensation matters. We believe an annual vote would be the best governance practice for the Company at this time.

The Board of Directors recommends voting in favor of an annual advisory vote to approve executive compensation.

PROPOSAL NO. 5—APPROVAL OF AN AMENDMENT TO THE TREVI THERAPEUTICS, INC. 2019 STOCK INCENTIVE PLAN

On April 24, 2025, or the Board Approval Date, our Board of Directors unanimously approved, subject to stockholder approval, an amendment to the Trevi Therapeutics, Inc. 2019 Stock Incentive Plan, or the 2019 Plan, to increase the number of shares available for issuance thereunder by 6,000,000 and to remove the “evergreen” provision that provides for an automatic annual increase in the number of shares available for grant thereunder, or the Plan Amendment. We are asking our stockholders to approve the Plan Amendment. We refer to the 2019 Plan as amended by the Plan Amendment as the Amended Plan.

Why We are Requesting Stockholder Approval

Our Board of Directors believes that our success depends, in large part, on our ability to maintain a competitive position by attracting, retaining and motivating the best talent in what is a competitive labor market. Central to these objectives is our equity-based compensation program, which is consistent with our compensation philosophy and the compensatory practices of other companies in our peer group and other companies that we compete with for talent. We and our Board of Directors understand that our equity-compensation needs must be balanced against the dilutive effect of such programs on our stockholders. To that end, and based on careful weighing of these considerations, as more fully described below, on the Board Approval Date, upon the recommendation of the compensation committee of the Board of Directors, and subject to stockholder approval, the Board of Directors approved the Plan Amendment. If this proposal is approved by our stockholders, we intend to register the additional shares reserved for issuance under the Amended Plan by filing a Registration Statement on Form S-8 as soon as practicable following such approval.

The 2019 Plan is our existing equity incentive plan, which became effective on May 7, 2019, in connection with our initial public offering. When the 2019 Plan was adopted, we expected that the share pool under the 2019 Plan would allow us to grant equity awards for the duration of the term of the 2019 Plan. However, the remaining share pool under the 2019 Plan (790,316 shares as of March 31, 2025) is insufficient to meet our equity compensation needs. The Plan Amendment increases the share pool under the 2019 Plan by 6,000,000 shares of common stock, in light of talent expansion and company growth, and removes the “evergreen” provision that provides for an automatic annual increase in the number of shares available for grant under the 2019 Plan. No other changes are being made to the 2019 Plan. If approved, the new shares reserved under the Amended Plan would represent approximately 6.01% of our 99,892,915 outstanding shares as of March 31, 2025. Our Board of Directors believes the proposed dilution to stockholders as a result of the Plan Amendment, particularly when taken together with the removal of the 2019 Plan’s “evergreen provision” is judicious and sustainable and, importantly, critical to meet our business goals.

We intend to utilize the Amended Plan as we have utilized the 2019 Plan: specifically, to grant equity awards to our employees, non-employee directors, consultants, and advisors in order to recruit, incentivize, retain and reward those who are critical to our success. Our compensation committee determined the requested number of shares for the Amended Plan based on projected new-hire equity awards, projected annual equity awards to our employees and non-employee directors, projected employee recognition and promotion awards, and an assessment of the magnitude of the share reserve under the Amended Plan that our stockholders would likely find acceptable. If stockholders approve the Plan Amendment, subject to adjustment in the event of stock splits and other similar events, awards may be made under the Amended Plan for up to a number of shares of common stock equal to the sum of: (i) 21,000,000 shares of common stock; and (ii) such additional number of shares of common stock (up to 11,000,000 shares) as is equal to the number of shares of common stock subject to awards granted under our 2012 Stock Incentive Plan, as amended, that were outstanding as of the date that the 2019 Plan became effective and which awards expire, terminate or are otherwise surrendered, cancelled, forfeited or repurchased by us at their original issuance price pursuant to a contractual repurchase right (subject, however, in the case of incentive stock options, to any limitations under the Internal Revenue Code of 1986, as amended, and any regulations thereunder, or the Code). The Plan Amendment would eliminate the evergreen provision contained in the 2019 Plan, and the 2019 Plan includes, and following the Plan Amendment, the Amended Plan would retain, several additional features that are consistent with protecting the interests of our stockholders and sound corporate governance practices, as described below.

The following table includes information, as of March 31, 2025, regarding all of our outstanding equity awards under all of our equity-based compensation plans and arrangements under which shares of common stock may be issued. This includes shares subject to outstanding awards under the 2019 Plan and up to 790,316 shares available under the 2019 Plan for future awards that we may make between March 31, 2025 and the date of the Annual Meeting, but does not include shares issuable or otherwise available for issuance under our 2019 Employee Stock Purchase Plan.

As of March 31, 2025, there were no outstanding (i) shares of restricted stock, (ii) restricted stock units, or RSUs, (iii) stock appreciation rights, or SARs, or (iv) other stock-based awards.

We expect that the proposed share pool under the Amended Plan will allow us to continue to grant equity awards at our historic rates for approximately one to two years, but the actual duration of the share pool may vary based on changes in participation, our stock price and market practice.

We believe that our stock-based compensation programs have been integral to our success in the past and will be important to our ability to succeed in the future. The 2019 Plan will expire on May 6, 2029. If the Plan Amendment is not approved by our stockholders, we will not be able to make equity incentive awards to meet our hiring and retention needs in a highly competitive market, which could have an adverse impact on our business. Further, if the Plan Amendment is not approved, we could be forced to increase cash compensation, which will reduce the resources we are able to allocate to meet our business needs and objectives. Therefore, the approval of the Plan Amendment is vital to our future success.

Our Board of Directors believes approval of the Plan Amendment is in the best interests of the Company and its stockholders and recommends a vote “FOR” the approval of the Plan Amendment.

Following below is a discussion of:

· Highlights of the Amended Plan;

· Reasons Why Stockholders Should Approve the Plan Amendment;

· Information Regarding Overhang and Dilution; and

· Description of the Amended Plan.

Highlights of the Amended Plan

The Amended Plan would no longer include the “evergreen” provision of the 2019 Plan and would retain several additional features that are consistent with protecting the interests of our stockholders and sound corporate governance practices. These features are highlighted below and are more fully described in the summary of the Amended Plan further below in this proposal. These descriptions assume and give effect to stockholder approval of the Plan Amendment and are qualified in their entirety by the specific language of the 2019 Plan and the Plan Amendment in Appendix A to this proxy statement.

Removal of Evergreen. The Plan Amendment will remove the “evergreen” provision of the 2019 Plan and the Amended Plan will not include any other provision that automatically increases the number of shares available for grant under the plan and therefore any increase to the maximum share reserve in the Amended Plan will be subject to approval by our stockholders, allowing our stockholders to have a greater say in our equity compensation programs.

Clawback Policy. In accepting an Award under the Amended Plan, a participant agrees to be bound by any clawback policy that we have in effect or may adopt in the future.

No Automatic Vesting of Awards on a Change in Control Event. The Amended Plan does not provide for the automatic vesting of awards in connection with a change in control event.

No Repricing of Awards. The Amended Plan prohibits the direct or indirect repricing of stock options or SARs without stockholder approval.

No Discounted Stock Options or SARs. All stock options and SARs must have an exercise or measurement price that is at least equal to the fair market value of the underlying common stock on the date of grant.

Material Amendments Require Stockholder Approval. Stockholder approval is required prior to an amendment of the Amended Plan that is required to be approved by our stockholders under the rules of the Nasdaq Global Market or any other exchange or marketplace on which our stock is listed or traded.

Reasons Why Stockholders Should Approve the Plan Amendment

Incentivizes, Retains and Motivates Talent. It is critical to our success that we incentivize, retain and motivate the best talent in what is a competitive labor market. Our equity-based compensation program has always been and will continue to be a key component in our ability to pay market-competitive compensation to our employees.

Aligns with Our Pay-for-Performance Compensation Philosophy. We believe that equity-based compensation is inherently performance-based. As the value of our stock appreciates, our employees receive greater compensation at the same time that our stockholders are receiving a greater return on their investment. Conversely, if the stock price does not appreciate following the grant of an equity award, then our employees would not receive any compensation in respect of stock options.

Aligns Employee and Director Interests with Stockholder Interests. Providing our employees and non-employee directors with compensation in the form of equity directly aligns the interests of those employees and non-employee directors with the interests of our stockholders. If the Plan Amendment is approved by our stockholders, we will be able to continue granting equity-based incentives that foster this alignment between our employees and non-employee directors and our stockholders.

Consistent with Stockholder Interests and Sound Corporate Governance. As described under the heading “Highlights of the Amended Plan” and more thoroughly below, the 2019 Plan was purposefully designed to include features that are consistent with the interests of our stockholders and sound corporate governance practices.

Information Regarding Overhang and Dilution

In developing our share request for the Amended Plan and analyzing the impact of utilizing equity as a means of compensation on our stockholders, we considered both our “overhang” and our “burn rate.”

Overhang is a measure of potential dilution, which we define as the sum of (i) the total number of shares underlying all equity awards outstanding and (ii) the total number of shares available for future award grants, divided by the number of shares of common stock outstanding. As of March 31, 2025, there were 9,705,194 shares underlying all equity awards outstanding, 790,316 shares available under the 2019 Plan for future awards between March 31, 2025 and the Annual Meeting, and 99,892,915 shares of common stock outstanding. Accordingly, our overhang at March 31, 2025 was 10.5%. If the 6,000,000 shares proposed to be authorized for grant under the Amended Plan are included in the calculation, our overhang on March 31, 2025 would have been 16.5%.

Burn rate provides a measure of the potential dilutive impact of our equity award program, which we calculate by dividing the number of shares subject to equity awards granted during the year by the basic weighted average number of shares outstanding. Set forth below is a table that reflects our burn rate for the 2024, 2023 and 2022 calendar years, as well as an average over those years. Our three-year average burn rate is below the three-year average burn rate of the other companies in our peer group.

(1) We define “gross burn rate” as the number of equity awards granted in the year divided by the basic weighted average number of shares of common stock outstanding. For purposes of this calculation, for each year, we counted the number of equity awards subject to any performance-based achievement based on the maximum number of shares of our common stock issuable under such awards.

Equity Compensation Plan Information

For more information on our equity compensation plans, please see the section titled “Executive Compensation—Equity Incentives” contained elsewhere in this proxy statement.

Description of the Amended Plan

The following is a brief summary of the 2019 Plan, as amended by the Plan Amendment, or the Amended Plan. A copy of the Plan Amendment is attached as Appendix A to this proxy statement. This summary assumes and gives effect to stockholder approval of the Plan Amendment and is qualified in its entirety by the specific language of the Amended Plan and the Plan Amendment found in Appendix A to this proxy statement. References to the Board of Directors in this summary shall include the compensation committee or any similar committee or sub-committee or our officers to the extent that our Board of Directors’ powers or authority under the Amended Plan have been delegated to such committee or officers, in accordance with the Amended Plan.

For purposes of this proposal and except where the context otherwise requires, the term “Company” and similar terms shall include any of our present or future parent or subsidiary corporations as defined in Sections 424(e) or (f) of the Code and any other business venture (including, without limitation, joint venture or limited liability company) in which we have a controlling interest, as determined by the Board of Directors.

Types of Awards; Shares Available for Awards; Share Counting Rules

The Amended Plan provides for the grant of incentive stock options intended to qualify under Section 422 of the Code, nonstatutory stock options, SARs, restricted stock, RSUs and other stock-based awards as described below, which we refer to, collectively, as awards or Awards.

Subject to adjustment in the event of stock splits, stock dividends and other similar events, awards may be made under the Amended Plan (any or all of which awards may be in the form of incentive stock options) for up to a number of shares of common stock equal to the sum of: (i) 21,000,000 shares of our common stock; and (ii) such additional number of shares of common stock (up to 11,000,000 shares) as is equal to the number of shares of common stock subject to awards granted under our 2012 Stock Incentive Plan, as amended, that were outstanding as of the date that the 2019 Plan became effective and which awards expire, terminate or are otherwise surrendered, cancelled, forfeited or repurchased by us at their original issuance price pursuant to a contractual repurchase right (subject, however, in the case of incentive stock options to any limitations under the Code). Shares of common stock issued under the Amended Plan may consist in whole or in part of authorized but unissued shares or treasury shares.

For purposes of counting the number of shares available for the grant of awards under the Amended Plan, all shares of common stock covered by SARs shall be counted against the number of shares available for the grant of awards under the Amended Plan. However, SARs that may be settled only in cash will not be so counted. In addition, if we grant a SAR in tandem with a stock option for the same number of shares of our common stock and provide that only one such award may be exercised, referred to as a tandem SAR, only the shares covered by the stock option, and not the shares covered by the tandem SAR, will be so counted, and the expiration of one in connection with the other’s exercise will not restore shares to the Amended Plan.

Shares covered by awards under the Amended Plan that expire or are terminated, surrendered, or cancelled without having been fully exercised or are forfeited in whole or in part (including as the result of shares subject to such award being repurchased by us at the original issuance price pursuant to a contractual repurchase right) or that result in any shares not being issued (including as a result of an award being settled in cash rather than stock) will again be available for the grant of awards under the Amended Plan (subject, in the case of incentive stock options, to any limitations under the Code). In the case of the exercise of a SAR, the number of shares counted against the shares available for the grant of awards under the Amended Plan will be the full number of shares subject to the SAR multiplied by the percentage of the SAR actually exercised, regardless of the number of shares actually used to settle the SAR upon exercise, and the shares covered by a tandem SAR will not again become available for grant upon the expiration or termination of the tandem SAR.

Shares of common stock that are delivered (by actual delivery, attestation, or net exercise) to us by a participant to purchase shares of common stock upon exercise of an award or to satisfy tax withholding obligations (including shares retained from the award creating the tax obligation) will be added back to the number of shares available for the future grant of awards under the Amended Plan.

In connection with a merger or consolidation of an entity with us or our acquisition of property or stock of an entity, our Board of Directors may grant awards under the Amended Plan in substitution for any stock options or other stock or stock-based awards granted by such entity or an affiliate thereof on such terms as our Board of Directors determines appropriate in the circumstances, notwithstanding any limitation on awards contained in the Amended Plan. No such substitute awards shall count against the overall share limit contained in the Amended Plan, except as required by reason of Section 422 and related provisions of the Code.

Descriptions of Awards

Stock Options. A participant who is awarded a stock option receives the right to purchase a specified number of shares of common stock at a specified exercise price and subject to the other terms and conditions that are specified in connection with the award agreement. A stock option that is not intended to be an “incentive stock option” is a “nonstatutory stock option.” Stock options may not be granted at an exercise price that is less than 100% of the fair market value of our common stock on the date of grant. If our Board of Directors approves the grant of a stock option with an exercise price to be determined on a future date, the exercise price may not be less than 100% of the fair market value of our common stock on that future date. Under present law, incentive stock options may not be granted at an exercise price less than 110% of the fair market value in the case of stock options granted to participants who hold more than 10% of the total combined voting power of all classes of our stock or any of our subsidiaries. Under the terms of the Amended Plan, stock options may not be granted for a term in excess of ten years (and, under present law, five years in the case of incentive stock options granted to participants who hold greater than 10% of the total combined voting power of all classes of our stock or any of our subsidiaries).

The Amended Plan permits participants to pay the exercise price of stock options using one or more of the following manners of payment: (i) payment by cash or by check, (ii) except as may otherwise be provided in the applicable award agreement or approved by our Board of Directors, in connection with a “cashless exercise” through a broker, (iii) to the extent provided in the applicable award agreement or approved by our Board of Directors, and subject to certain conditions, by delivery to us (either by actual delivery or attestation) of shares of common stock owned by the participant valued at their fair market value, (iv) to the extent provided in an applicable nonstatutory stock option award agreement or approved by our Board of Directors, by delivery of a notice of “net exercise” as a result of which we will retain a number of shares of common stock otherwise issuable pursuant to the stock option equal to the aggregate exercise price for the portion of the stock option being exercised divided by the fair market value of our common stock on the date of exercise, (v) to the extent permitted by applicable law and provided for in the applicable award agreement or approved by our Board of Directors, by any other lawful means, or (vi) by any combination of these forms of payment.

Stock Appreciation Rights. A participant who is awarded a SAR receives, upon exercise, a number of shares of our common stock, or cash (or a combination of shares of our common stock and cash) determined by reference to appreciation, from and after the date of grant, in the fair market value of a share of our common stock over the measurement price. The Amended Plan provides that the measurement price of a SAR may not be less than 100% of the fair market value of our common stock on the date the SAR is granted (provided, however, that if our Board of Directors approves the grant of a SAR effective as of a future date, the measurement price shall not be less than 100% of the fair market value on such future date) and that SARs may not be granted with a term in excess of 10 years.

Limitation on Repricing of Stock Options or SARs. Unless such action is approved by our stockholders or otherwise permitted under the terms of the Amended Plan in connection with certain changes in capitalization and reorganization events, we may not (i) amend any outstanding stock option or SAR granted under the Amended Plan to provide an exercise price or measurement price per share that is lower than the then-current exercise price or measurement price per share of such outstanding stock option or SAR, (ii) cancel any outstanding stock option or SAR (whether or not granted under the Amended Plan) and grant in substitution therefor new awards under the Amended Plan (other than certain substitute awards issued in connection with a merger or consolidation of an entity with us or an acquisition by us, described above) covering the same or a different number of shares of our common stock and having an exercise price or measurement price per share lower than the then-current exercise price or measurement price per share of the cancelled stock option or SAR, (iii) cancel in exchange for a cash payment any outstanding stock option or SAR with an exercise price or measurement price per share above the then-current fair market value of our common stock, or (iv) take any other action under the Amended Plan that constitutes a “repricing” within the meaning of the rules of the Nasdaq Global Market or any other exchange or marketplace on which our stock is listed or traded.

Restricted Stock Awards. A participant who is granted a restricted stock award is entitled to acquire shares of our common stock, subject to our right to repurchase all or part of such shares at their issue price or other stated or formula price (or to require forfeiture of such shares if issued at no cost), in the event that the conditions specified in the applicable award are not satisfied prior to the end of the applicable restriction period established for such award. Unless provided otherwise in the applicable award agreement, dividends (whether paid in cash, stock or property) declared and paid by us with respect to shares of restricted stock will be paid to the participant only if and when such shares become free from the restrictions on transferability and forfeitability that apply to such shares.

Restricted Stock Unit Awards. A participant who is granted an RSU award is entitled to receive shares of our common stock, or cash equal to the fair market value of such shares or a combination thereof, in the event that the conditions specified in the applicable award are satisfied, with such shares to be delivered at the time such award vests or on a deferred basis pursuant to the terms and conditions

established by our Board of Directors. Our Board of Directors may provide that settlement of RSUs will be deferred, on a mandatory basis or at the election of the participant, in a manner that complies with Section 409A of the Code. A participant has no voting rights with respect to any RSU. An RSU award agreement may provide the applicable participant with the right to receive an amount equal to any dividends or other distributions declared and paid on an equal number of outstanding shares of our common stock. Any such dividend equivalents may be settled in cash and/or shares of our common stock and will be subject to the same restrictions on transfer and forfeitability as the RSUs with respect to which such dividend equivalents are awarded, in each case to the extent provided in the applicable award agreement.

Other Stock-Based Awards. Under the Amended Plan, our Board of Directors may grant other awards of shares of our common stock, and other awards that are valued in whole or in part by reference to, or are otherwise based on, shares of our common stock or other property, having such terms and conditions as our Board of Directors may determine. We refer to these types of awards as other stock-based awards. Other stock-based awards may be available as a form of payment in settlement of other awards granted under the Amended Plan or as payment in lieu of compensation to which a participant is otherwise entitled. Other stock-based awards may be paid in shares of our common stock or in cash, as our Board of Directors may determine.

Eligibility to Receive Awards

All of our employees, officers, and directors, as well as our consultants and advisors, are eligible to receive awards under the Amended Plan. However, incentive stock options may only be granted to our employees, employees of our present or future parent or subsidiary corporations as defined in Sections 424(e) or (f) of the Code, and employees of any other entities the employees of which are eligible to receive incentive stock options under the Code.

As of March 31, 2025, approximately 35 persons were eligible to receive awards under the 2019 Plan, including five executive officers (who are current employees), 23 employees (excluding executive officers), five non-employee directors, two consultants and zero advisors (excluding consultants).

On March 31, 2025, the last reported sale price of our common stock on the Nasdaq Global Market was $6.29.

Transferability of Awards

Awards may not be sold, assigned, transferred, pledged or otherwise encumbered by a participant, either voluntarily or by operation of law, except by will or the laws of descent and distribution or, other than in the case of an incentive stock option, pursuant to a qualified domestic relations order. During the life of the participant, awards are exercisable only by the participant. However, except with respect to awards that are subject to Section 409A of the Code, our Board of Directors may permit or provide in an award for the gratuitous transfer of the award by the participant to or for the benefit of any immediate family member, family trust or other entity established for the benefit of the participant and/or an immediate family member thereof if we would be eligible to use a Form S-8 under the Securities Act of 1933, as amended, for the registration of the sale of the common stock subject to such award to the proposed transferee. Further, we are not required to recognize any such permitted transfer until such time as the permitted transferee has, as a condition to the transfer, delivered to us a written instrument in form and substance satisfactory to us confirming that such transferee will be bound by all of the terms and conditions of the award. None of the restrictions described in this paragraph prohibit a transfer from the participant to us.

No Rights as a Stockholder

No participant or designated beneficiary shall have any rights as a stockholder with respect to any shares of common stock to be distributed with respect to an award granted under the Amended Plan until becoming a record holder of such shares, subject to the terms of an award agreement.

Clawback

In accepting an award under the Amended Plan, a participant agrees to be bound by any clawback policy that we have in effect or may adopt in the future.

Awards Granted under the 2019 Plan

The following table sets forth information about equity-based awards granted under the 2019 Plan since adoption of the 2019 Plan through March 31, 2025, to the individuals and groups described in the below table.

New Plan Benefits Table

The granting of awards under the Amended Plan is discretionary, and we cannot now determine the number or type of awards to be granted in the future to any particular person or group, other than as set forth below. We are obligated to grant each of our non-employee directors a stock option to purchase 90,000 shares of our common stock upon initial election to the Board of Directors and, after such non-employee director has served on the Board of Directors for at least six months, a stock option to purchase 45,000 shares of our common stock on the date of each annual meeting thereafter, including the Annual Meeting, under the terms of our Non-Employee Director Compensation Policy. The compensation we pay to our directors is further discussed below under “Corporate Governance—Director Compensation.”

(1) Represents the annual stock option award to purchase shares of common stock to be granted in 2025 to each non-employee director. Under our Non-Employee Director Compensation Policy, each non-employee director will receive an annual stock option award of 45,000 shares on the date of our annual stockholder meeting. The exercise price of each stock option to be granted under this policy will be equal to the fair market value of our common stock on the date of grant. Excludes (i) stock options that the non-employee directors will be entitled to receive under our Non-Employee Director Compensation Policy for subsequent years following 2025 and (ii) any discretionary awards that any non-employee director may be awarded under the Amended Plan.

Administration

The Amended Plan will be administered by our Board of Directors. Our Board of Directors has the authority to grant awards and to adopt, amend and repeal the administrative rules, guidelines and practices relating to the Amended Plan that it deems advisable and to construe and interpret the provisions of the Amended Plan and any award agreements entered into under the Amended Plan. Our Board of Directors may correct any defect, supply any omission or reconcile any inconsistency in the Amended Plan or any award in

the manner and to the extent it shall deem expedient and it shall be the sole and final judge of such expediency. All decisions by our Board of Directors will be made in our Board of Directors’ sole discretion and will be final and binding on all persons having or claiming any interest in the Amended Plan or in any award.

Pursuant to the terms of the Amended Plan, our Board of Directors may delegate any or all of its powers under the Amended Plan to one or more committees or subcommittees of our Board of Directors. The Board of Directors has authorized the compensation committee to administer the Amended Plan.

Subject to any requirements of applicable law, the Board of Directors may delegate to one or more officers of the Company the power to grant awards (subject to any limitations under the Amended Plan) to employees or officers of the Company and to exercise such other powers under the Amended Plan as the Board of Directors may determine, provided that the Board of Directors shall fix the terms of awards to be granted by such officers, the maximum number of shares subject to awards that the officers may grant, and the time period in which such awards may be granted; and provided further that no officer shall be authorized to grant awards to any “executive officer” (as defined by Rule 3b-7 under the Securities Exchange Act of 1934, as amended, or the Exchange Act), or to any “officer” (as defined by Rule 16a-1(f) under the Exchange Act).

Subject to applicable limitations contained in the Amended Plan, the Board of Directors, the compensation committee, or any other committee or subcommittee or Company officer to whom the Board of Directors has delegated authority pursuant to the Amended Plan, as the case may be, selects the recipients of awards and determines (i) the number of shares of common stock, cash or other consideration covered by awards and the terms and conditions of such awards, including the dates upon which such awards become exercisable or otherwise vest, (ii) the exercise or measurement price of awards, if any, and (iii) the duration of awards.

Except as otherwise provided in the Amended Plan, each award under the Amended Plan may be made alone or in addition or in relation to any other award. The terms of each award need not be identical, and our Board of Directors need not treat participants uniformly. Our Board of Directors will determine the effect on an award of the disability, death, termination or other cessation of employment, authorized leave of absence or other change in the employment or other status of a participant, and the extent to which, and the period during which, the participant (or the participant’s legal representative, conservator, guardian or designated beneficiary) may exercise rights under an award.

The Board of Directors may at any time provide that any award shall become immediately exercisable in whole or in part, free from some or all restrictions or conditions or otherwise realizable in whole or in part, as the case may be.

In the event of any stock split, reverse stock split, stock dividend, recapitalization, combination of shares, reclassification of shares, spin-off or other similar change in capitalization or event, or any dividend or distribution to holders of our common stock, other than an ordinary cash dividend, we are required to make equitable adjustments (or make substituted awards, as applicable), in the manner determined by our Board of Directors, to (i) the number and class of securities available under the Amended Plan, (ii) the share counting rules set forth in the Amended Plan, (iii) the number and class of securities and exercise price per share of each outstanding stock option, (iv) the share and per share provisions and the measurement price of each outstanding SAR, (v) the number of shares subject to and the repurchase price per share subject to each outstanding award of restricted stock and (vi) the share and per share related provisions and purchase price, if any, of each outstanding RSU award and each outstanding other stock-based award. In the event we effect a split of our common stock by means of a stock dividend and the exercise price of and the number of shares subject to an outstanding stock option are adjusted as of the date of the distribution of the dividend (rather than as of the record date for such dividend), then a participant who exercises a stock option between the record date and the distribution date for such stock dividend shall be entitled to receive, on the distribution date, the stock dividend with respect to the shares of common stock acquired upon such stock option exercise, notwithstanding the fact that such shares were not outstanding as of the close of business on the record date for such stock dividend.

We will indemnify and hold harmless each director, officer, employee or agent to whom any duty or power relating to the administration or interpretation of the Amended Plan has been or will be delegated against any cost or expense (including attorneys’ fees) or liability (including any sum paid in settlement of a claim with our Board of Directors’ approval) arising out of any act or omission to act concerning the Amended Plan unless arising out of such person’s own fraud or bad faith.

Amendment of Awards. Except as otherwise provided under the Amended Plan with respect to repricing outstanding stock options or SARs and with respect to actions requiring stockholder approval, our Board of Directors may amend, modify or terminate any outstanding award, including but not limited to, substituting therefor another award of the same or a different type, changing the date of exercise or realization, and converting an incentive stock option to a nonstatutory stock option, provided that the participant’s consent to any such action will be required unless our Board of Directors determines that the action, taking into account any related action, does not materially and adversely affect the participant’s rights under the Amended Plan or the change is otherwise permitted under the terms of the Amended Plan in connection with certain corporate events.

Reorganization Events

The Amended Plan contains provisions addressing the consequences of any reorganization event. A reorganization event is defined under the Amended Plan as (i) any merger or consolidation of us with or into another entity as a result of which all of our common stock is converted into or exchanged for the right to receive cash, securities or other property, or is cancelled, (ii) any transfer or disposition of all of our common stock for cash, securities or other property pursuant to a share exchange or other transaction or (iii) our liquidation or dissolution.

Provisions Applicable to Awards Other than Restricted Stock. Under the Amended Plan, if a reorganization event occurs, our Board of Directors may take any one or more of the following actions as to all or any (or any portion of) outstanding awards other than restricted stock on such terms as our Board of Directors determines (except to the extent specifically provided otherwise in an applicable award agreement or another agreement between a participant and us): (i) provide that awards shall be assumed, or substantially equivalent awards shall be substituted, by the acquiring or succeeding corporation (or an affiliate thereof), (ii) upon written notice to a participant, provide that all of the participant’s unvested awards will be forfeited immediately before the reorganization event and/or that all unexercised awards will terminate immediately prior to the consummation of such reorganization event unless exercised by the participant (to the extent then exercisable) within a specified period following the date of such notice, (iii) provide that outstanding awards shall become exercisable, realizable, or deliverable, or restrictions applicable to an award shall lapse, in whole or in part prior to or upon such reorganization event, (iv) in the event of a reorganization event under the terms of which holders of shares of common stock will receive upon consummation thereof a cash payment for each share surrendered in the reorganization event, or the Acquisition Price, make or provide for a cash payment to participants with respect to an award held by a participant equal to (I) the number of shares of our common stock subject to the vested portion of the award (after giving effect to any acceleration of vesting that occurs upon or immediately prior to such reorganization event) multiplied by (II) the excess, if any, of (A) the Acquisition Price over (B) the exercise, measurement or purchase price of such award and any applicable tax withholdings, in exchange for the termination of such award, (v) provide that, in connection with our liquidation or dissolution, awards shall convert into the right to receive liquidation proceeds (if applicable, net of the exercise, measurement or purchase price thereof and any applicable tax withholdings) and (vi) any combination of the foregoing.

Our Board of Directors is not obligated to treat all awards, all awards held by a participant, or all awards of the same type, identically. Certain RSU awards that are subject to Section 409A of the Code will be settled in accordance with the terms of the applicable award agreement or as otherwise specified in the Amended Plan.

Provisions Applicable to Restricted Stock. Upon the occurrence of a reorganization event other than our liquidation or dissolution, our repurchase and other rights with respect to outstanding restricted stock will inure to the benefit of our successor and will, unless our Board of Directors determines otherwise, apply to the cash, securities or other property which our common stock was converted into or exchanged for pursuant to such reorganization event in the same manner and to the same extent as they applied to such restricted stock. However, our Board of Directors may provide for termination or deemed satisfaction of such repurchase or other rights under the instrument evidencing any restricted stock or any other agreement between a participant and us, either initially or by amendment. Upon the occurrence of a reorganization event involving our liquidation or dissolution, except to the extent specifically provided to the contrary in the instrument evidencing any award of restricted stock or any other agreement between the participant and us, all restrictions and conditions on all restricted stock then outstanding shall automatically be deemed terminated or satisfied.

Provisions for Foreign Participants

The Board of Directors may establish one or more sub-plans under the Amended Plan to satisfy applicable securities, tax or other laws of various jurisdictions. The Board of Directors will establish such sub-plans by adopting supplements to the Amended Plan containing any limitations on the Board of Directors’ discretion under the Amended Plan and any additional terms and conditions not otherwise inconsistent with the Amended Plan as the Board of Directors deems necessary or desirable. All supplements adopted by the Board of Directors will be deemed to be part of the Amended Plan, but each supplement will only apply to participants within the affected jurisdiction.

Withholding

The participant must satisfy all applicable federal, state, and local or other income and employment tax withholding obligations before we will deliver stock certificates or otherwise recognize ownership of common stock under an award. We may elect to satisfy the withholding obligations through additional withholding on salary or wages. If we elect not to or cannot withhold from other compensation, the participant must pay us the full amount, if any, required for withholding or have a broker tender to us cash equal to the withholding obligations. Payment of withholding obligations is due before we will issue any shares on exercise, vesting or release from forfeiture of an award or at the same time as payment of the exercise or purchase price, unless we determine otherwise. If

provided for in an award or approved by the compensation committee, a participant may satisfy the tax obligations in whole or in part by delivery (either by actual delivery or attestation) of shares of common stock, including shares retained from the award creating the tax obligation, valued at their fair market value. However, except as otherwise provided by the compensation committee, the total tax withholding where stock is being used to satisfy such tax obligations cannot exceed our minimum statutory withholding obligations (based on minimum statutory withholding rates for federal and state tax purposes, including payroll taxes, that are applicable to such supplemental taxable income), except that, to the extent that we are able to retain shares of common stock having a fair market value that exceeds the statutory minimum applicable withholding tax without financial accounting implications or we are withholding in a jurisdiction that does not have a statutory minimum withholding tax, we may retain such number of shares (up to the number of shares having a fair market value equal to the maximum individual statutory rate of tax) as we shall determine in our sole discretion to satisfy the tax liability associated with any award. Shares used to satisfy tax withholding requirements cannot be subject to any repurchase, forfeiture, unfulfilled vesting or other similar requirements.

Amendment or Termination

No award may be granted under the Amended Plan after May 7, 2029, but awards previously granted may extend beyond that date. Our Board of Directors may amend, suspend or terminate the Amended Plan or any portion of the Amended Plan at any time, provided that no amendment that would require stockholder approval under the rules of the Nasdaq Global Market or any other marketplace or exchange on which our common stock is listed or traded will be effective unless and until our stockholders approve such amendment. If at any time the approval of our stockholders is required as to any other modification or amendment under Section 422 of the Code or any successor provision with respect to incentive stock options, our Board of Directors may not effect such modification or amendment without such approval.

Unless otherwise specified in the amendment, any amendment to the Amended Plan adopted in accordance with the procedures described above will apply to, and be binding on the holders of, all awards outstanding under the Amended Plan at the time the amendment is adopted, provided that our Board of Directors determines that such amendment, taking into account any related action, does not materially and adversely affect the rights of participants under the Amended Plan. No award will be made that is conditioned on stockholder approval of any amendment to the Amended Plan unless the award provides that (i) it will terminate or be forfeited if stockholder approval of such amendment is not obtained within no more than 12 months from the date the award was granted and (ii) it may not be exercised or settled (or otherwise result in the issuance of shares of our common stock) prior to the receipt of such stockholder approval.

If stockholders do not approve the Plan Amendment, the Plan Amendment will not go into effect and we will not grant any awards under the 2019 Plan in excess of the current share reserve. In this event, the Board of Directors will consider whether to adopt alternative arrangements based on its assessment of our needs.

Federal Income Tax Consequences

The following is a summary of the United States federal income tax consequences that generally will arise with respect to awards granted under the Amended Plan. This summary is based on the federal tax laws in effect as of the date of this proxy statement. In addition, this summary assumes that all awards are exempt from, or comply with, the rules under Section 409A of the Code regarding nonqualified deferred compensation. Changes to these laws could alter the tax consequences described below.

Incentive Stock Options. A participant will not have income upon the grant of an incentive stock option. Also, except as described below, a participant will not have income upon exercise of an incentive stock option if the participant has been employed by us or its corporate parent or 50% or majority-owned corporate subsidiary at all times beginning with the stock option grant date and ending three months before the date the participant exercises the stock option. If the participant has not been so employed during that time, then the participant will be taxed as described below under “Nonstatutory Stock Options.” The exercise of an incentive stock option may subject the participant to the alternative minimum tax.

A participant will have income upon the sale of the stock acquired under an incentive stock option at a profit (if sales proceeds exceed the exercise price). The type of income will depend on when the participant sells the stock. If a participant sells the stock more than two years after the stock option was granted and more than one year after the stock option was exercised, then all of the profit will be long-term capital gain. If a participant sells the stock prior to satisfying these waiting periods, then the participant will have engaged in a disqualifying disposition and a portion of the profit will be ordinary income and a portion may be capital gain. This capital gain will be long-term if the participant has held the stock for more than one year and otherwise will be short-term. If a participant sells the stock at a loss (sales proceeds are less than the exercise price), then the loss will be a capital loss. This capital loss will be long-term if the participant held the stock for more than one year and otherwise will be short-term.

Nonstatutory Stock Options. A participant will not have income upon the grant of a nonstatutory stock option. A participant will have compensation income upon the exercise of a nonstatutory stock option equal to the value of the stock on the day the participant exercised the stock option less the exercise price. Upon sale of the stock, the participant will have capital gain or loss equal to the difference between the sales proceeds and the value of the stock on the day the stock option was exercised. This capital gain or loss will be long-term if the participant has held the stock for more than one year and otherwise will be short-term.

Stock Appreciation Rights. A participant will not have income upon the grant of a SAR. A participant generally will recognize compensation income upon the exercise of a SAR equal to the amount of the cash and the fair market value of any stock received. Upon the sale of the stock, the participant will have capital gain or loss equal to the difference between the sales proceeds and the value of the stock on the day the SAR was exercised. This capital gain or loss will be long-term if the participant held the stock for more than one year and otherwise will be short-term.

Restricted Stock Awards. A participant will not have income upon the grant of restricted stock unless an election under Section 83(b) of the Code is made within 30 days of the date of grant. If a timely 83(b) election is made, then a participant will have compensation income equal to the value of the stock less the purchase price, if any. When the stock is sold, the participant will have capital gain or loss equal to the difference between the sales proceeds and the value of the stock on the date of grant. If the participant does not make an 83(b) election, then when the stock vests the participant will have compensation income equal to the value of the stock on the vesting date less the purchase price, if any. When the stock is sold, the participant will have capital gain or loss equal to the sales proceeds less the value of the stock on the vesting date. Any capital gain or loss will be long-term if the participant held the stock for more than one year and otherwise will be short-term.

Restricted Stock Units. A participant will not have income upon the grant of an RSU. A participant is not permitted to make a Section 83(b) election with respect to an RSU award. When the shares of common stock are delivered with respect to the RSUs (which may be upon vesting or may be at a later date), the participant will have income on the date of delivery in an amount equal to the fair market value of the stock on such date less the purchase price, if any. When the stock is sold, the participant will have capital gain or loss equal to the sales proceeds less the value of the stock on the delivery date. Any capital gain or loss will be long-term if the participant held the stock for more than one year and otherwise will be short-term.

Other Stock-Based Awards. The tax consequences associated with any other stock-based award will vary depending on the specific terms of such award. Among the relevant factors are whether or not the award has a readily ascertainable fair market value, whether or not the award is subject to forfeiture provisions or restrictions on transfer, the nature of the property to be received by the participant under the award, and the participant’s holding period and tax basis for the award or underlying common stock.

Tax Consequences to the Company. There will be no tax consequences to us except we will be entitled to a deduction when a participant has compensation income, subject to the limitations of Section 162(m) of the Code

The Board of Directors recommends voting “FOR” the approval of the Amendment to the Trevi Therapeutics, Inc. 2019 Stock Incentive Plan.

CORPORATE GOVERNANCE

Director Nomination Process

Our nominating and corporate governance committee is responsible for identifying individuals qualified to serve as directors, consistent with criteria approved by our board, and recommending the persons to be nominated for election as directors, except where we are legally required by contract, law or otherwise to provide third parties with the right to nominate.

We have no formal policy regarding board diversity, but our Corporate Governance Guidelines provide that the background and qualifications of the members of our Board of Directors considered as a group should provide a significant breadth of experience, knowledge and ability to assist our Board of Directors in fulfilling its responsibilities. In this regard, the nominating and corporate governance committee takes into consideration the diversity (for example, with respect to gender, race and national origin) of our directors. The nominating and corporate governance committee does not apply any particular weighting of diversity or any other characteristic in evaluating nominees and directors. Nominees are not discriminated against on the basis of race, religion, national origin, sex, sexual orientation, disability or any other basis proscribed by law.

The process followed by our nominating and corporate governance committee to identify and evaluate director candidates includes requests to board members and others for recommendations, meetings from time to time to evaluate biographical information and background material relating to potential candidates and interviews of selected candidates by members of the committee and our

Board of Directors. The qualifications, qualities and skills that our nominating and corporate governance committee believes must be met by a committee-recommended nominee for a position on our Board of Directors are as follows:

The nominating and corporate governance committee may use a third-party search firm in those situations where particular qualifications are required or where existing contacts are not sufficient to identify an appropriate candidate.

Stockholders may recommend individuals to the nominating and corporate governance committee for consideration as potential director candidates. Any such proposals should be submitted to our corporate secretary at our principal executive offices and should include appropriate biographical and background material to allow the nominating and corporate governance committee to properly evaluate the potential director candidate and the number of shares of our stock beneficially owned by the stockholder proposing the candidate. The specific requirements for the information that is required to be provided for such recommendations to be considered are specified in our amended and restated bylaws and must be received by us no later than the date referenced below under the heading “Stockholder Proposals.” Assuming that biographical and background material has been provided on a timely basis, any recommendations received from stockholders will be evaluated in the same manner as potential nominees proposed by the nominating and corporate governance committee. If our Board of Directors determines to nominate a stockholder-recommended candidate and recommends his or her election, then his or her name will be included on our proxy card for the next Annual Meeting of Stockholders.

Director Independence

Applicable Nasdaq rules require a majority of a listed company’s board of directors to be comprised of independent directors within one year of listing. In addition, Nasdaq rules require that, subject to specified exceptions, each member of a listed company’s audit, compensation and nominating and corporate governance committees be independent under the Securities Exchange Act of 1934, as amended, or the Exchange Act. Audit committee members must also satisfy the independence criteria set forth in Rule 10A-3 under the Exchange Act, and compensation committee members must also satisfy the independence criteria set forth in Rule 10C-1 under the Exchange Act. Under applicable Nasdaq rules, a director will only qualify as an “independent director” if, in the opinion of the listed company’s board of directors, that person does not have a relationship that would interfere with the exercise of independent judgment in carrying out the responsibilities of a director. In order to be considered independent for purposes of Rule 10A-3, a member of an audit committee of a listed company may not, other than in his or her capacity as a member of the audit committee, the board of directors, or any other board committee, accept, directly or indirectly, any consulting, advisory, or other compensatory fee from the listed company or any of its subsidiaries or otherwise be an affiliated person of the listed company or any of its subsidiaries. In order to be considered independent for purposes of Rule 10C-1, the board of directors of a listed company must consider, for each member of the company’s compensation committee, all factors specifically relevant to determining whether a director has a relationship to such company that is material to that director’s ability to be independent from management in connection with the duties of a compensation committee member, including, but not limited to: (1) the source of compensation of the director, including any consulting, advisory or other compensatory fee paid by such company to the director; and (2) whether the director is affiliated with the company or any of its subsidiaries or affiliates.

In April 2025, our Board of Directors undertook a review of the composition of our Board of Directors and the independence of each director. Based upon information requested from and provided by each director concerning his or her background, employment and affiliations, including family relationships, our Board of Directors has determined that each of our directors, with the exception of Ms. Good, is an “independent director” as defined under applicable Nasdaq rules. In making such determination, our Board of Directors considered the relationships that each such non-employee director has with our Company and all other facts and circumstances that our Board of Directors deemed relevant in determining his or her independence, including the beneficial ownership of our capital stock by each non-employee director. Ms. Good is not an independent director under these rules because she is our President and Chief Executive Officer.

There are no family relationships among any of our directors or executive officers.

Board Committees

Our Board of Directors has established an audit committee, a compensation committee, and a nominating and corporate governance committee. Each of the audit committee, compensation committee and nominating and corporate governance committee operates under a charter. A current copy of the charter for each of the audit committee, compensation committee and the nominating and corporate governance committee is posted under the heading "Corporate Governance" on the Investors & News section of our website, which is located at https://www.trevitherapeutics.com.

Audit Committee

The current members of our audit committee are Mr. Colangelo, Mr. Heffernan, and Ms. VanLent. Ms. VanLent is the chair of our audit committee. Our Board of Directors has determined that each of Mr. Colangelo, Mr. Heffernan and Ms. VanLent is independent within the meaning of Rule 10A-3 under the Exchange Act. Our Board of Directors has determined that Ms. VanLent is an “audit committee financial expert” as defined in applicable SEC rules. Our Board of Directors believes that the composition of our audit committee meets the requirements for independence under current Nasdaq and SEC rules and regulations. Our audit committee assists our Board of Directors in its oversight of our accounting and financial reporting process and the audits of our consolidated financial statements. The audit committee met four times during the year ended December 31, 2024, including telephonic meetings. Our audit committee’s responsibilities include:

All audit services to be provided to us and all non-audit services, other than de minimis non-audit services, to be provided to us by our registered public accounting firm must be approved in advance by our audit committee.

Compensation Committee

The members of our compensation committee are Messrs. Colangelo, Heffernan and Mathers. Mr. Heffernan is the chair of our compensation committee. Our Board of Directors has determined that each of Messrs. Colangelo, Heffernan and Mathers are independent within the meaning of Rule 10C-1 under the Exchange Act. Our compensation committee assists our Board of Directors in the discharge of its responsibilities relating to the compensation of our executive officers. The compensation committee met three times during the year ended December 31, 2024, including telephonic meetings. Our compensation committee’s responsibilities include:

Nominating and Corporate Governance Committee

The members of our nominating and corporate governance committee are Dr. Meeker and Ms. VanLent. Dr. Cassella served as a member of and the chair of our nominating and corporate governance committee until September 2024. The nominating and corporate governance committee met one time during the year ended December 31, 2024, including telephonic meetings. Our nominating and corporate governance committee’s responsibilities include:

Board and Committee Meetings Attendance

The full Board of Directors met six times during 2024. During 2024, each member of the Board of Directors attended in person or participated in 75% or more of the aggregate of (i) the total number of meetings of the Board of Directors (held during the period for which such person has been a director) and (ii) the total number of meetings held by all committees of the Board of Directors on which such person served (during the periods that such person served).

Director Attendance at Annual Meeting of Stockholders

Although we do not have a formal policy regarding attendance by members of our Board of Directors at our Annual Meeting of Stockholders, we encourage all of our directors to attend. Six of our then-serving directors attended our Annual Meeting of Stockholders in 2024.

Code of Business Conduct and Ethics

We have adopted a written code of business conduct and ethics that applies to our directors, officers and employees, including our principal executive officer (PEO), principal financial officer, principal accounting officer or controller, or persons performing similar functions. A copy of the code is posted under the heading “Corporate Governance” on the Investors & News section of our website, which is located at https://www.trevitherapeutics.com. If we make any substantive amendments to, or grant any waivers from, the code of business conduct and ethics for any officer or director, we will disclose the nature of such amendment or waiver on our website or in a current report on Form 8-K.

Corporate Governance Guidelines

Our Board of Directors has adopted corporate governance guidelines to assist in the exercise of its duties and responsibilities and to serve the best interests of our company and our stockholders. The guidelines provide that:

A copy of the corporate governance guidelines is posted under the heading “Corporate Governance” on the Investors & News section of our website, which is located at https://www.trevitherapeutics.com.

Board Leadership Structure and Board’s Role in Risk Oversight

Our corporate governance guidelines provide that the roles of chairman of the board and chief executive officer may be separated or combined. Our Board of Directors has considered its leadership structure and determined that, at this time, the roles of chairman of the Board of Directors and chief executive officer should be separate. Separating the chairman and the chief executive officer positions allows our Chief Executive Officer, Ms. Good, to focus on running the business, while allowing our chairman of the Board of Directors, Dr. Meeker, to lead our board in its fundamental role of providing advice to and oversight of management.

Our corporate governance guidelines also provide that in the event the chairman of our Board of Directors is not an independent director under Nasdaq rules, the nominating and corporate governance committee may designate an independent director to serve as

“Lead Director”, who shall be approved by a majority of the independent directors. The duties of the Lead Director include the following:

Our Board of Directors believes that this structure ensures a greater role for the independent directors in the oversight of our company and active participation of the independent directors in setting agendas and establishing priorities and procedures for the work of our Board of Directors. Our Board of Directors has three standing committees that currently consist of independent directors. Our Board of Directors delegates substantial responsibilities to the committees, which then report their activities and actions back to the full Board of Directors. We believe that the independent committees of our Board of Directors promote effective independent governance. We believe this structure represents an appropriate allocation of roles and responsibilities for our company at this time because it strikes an effective balance between management and independent leadership participation in our Board of Director proceedings.

Risk is inherent with every business and how well a business manages risk can ultimately determine its success. We face a number of risks, including those described under “Risk Factors” in our Annual Report on Form 10-K for the fiscal year ended December 31, 2024. Our Board of Directors is actively involved in oversight of risks that could affect us. This oversight is conducted primarily by our full Board of Directors, which has responsibility for general oversight of risks. Our Board of Directors oversees our risk management processes directly and through its committees. Our management is responsible for risk management on a day-to-day basis and our board and its committees oversee the risk management activities of management. Our Board of Directors satisfies this responsibility through full reports by each committee chair regarding the committee’s considerations and actions, as well as through regular reports directly from officers responsible for oversight of particular risks within our company. Our audit committee oversees risk management activities related to financial controls and legal and compliance risks. Our compensation committee oversees risk management activities relating to our compensation policies and practices. Our nominating and corporate governance committee oversees risk management activities relating to board composition and management succession planning. In addition, members of our senior management team attend our board meetings and are available to address any questions or concerns raised by the Board of Directors on risk management and any other matters. Our Board of Directors believes that full and open communication between management and the Board of Directors is essential for effective risk management and oversight.

Communication with Our Directors

Any interested party with concerns about our company may report such concerns to the Board of Directors, or the chairman of our Board of Directors, by submitting a written communication to the attention of the board the chairman at the following address:

c/o Trevi Therapeutics, Inc.

195 Church Street

16th Floor

New Haven, CT 06510

United States

You may submit your concern anonymously or confidentially by postal mail. You may also indicate whether you are a stockholder, customer, supplier, or other interested party.

Absent unusual circumstances or as contemplated by the committee charters, the chairman of our Board of Directors shall, subject to advice and assistance from our legal counsel, (1) be primarily responsible for monitoring communications from stockholders and other interested parties, and (2) provide copies or summaries of such communications to the other directors as he or she considers appropriate.

A copy of any such written communication may be retained for a reasonable period of time. The director may discuss the matter with our legal counsel, with independent advisors, with non-management directors, or with our management, or may take other action or no action as the board or director determines in good faith, using reasonable judgment and discretion.

Communications may be forwarded to all directors if they relate to important substantive matters and include suggestions or comments that may be important for the directors to know. In general, communications relating to corporate governance and corporate

strategy are more likely to be forwarded than communications relating to ordinary business affairs, personal grievances and matters as to which we receive repetitive or duplicative communications.

Limitations on Liability and Indemnification

Our restated certificate of incorporation limits the personal liability of directors and officers for breach of fiduciary duty to the maximum extent permitted by the Delaware General Corporation Law, or the DGCL, and provides that no director or officer will have personal liability to us (in the case of directors) or to our stockholders (in the case of directors and officers) for monetary damages for breach of fiduciary duty as a director or officer. However, these provisions do not eliminate or limit liability:

Any amendment to or repeal of these provisions will not eliminate or reduce the effect of these provisions in respect of any act, omission or claim that occurred or arose prior to such amendment or repeal. If the DGCL is amended to provide for further limitations on the personal liability of directors or officers of corporations, then the personal liability of our directors and officers will be further limited to the greatest extent permitted by the DGCL.

In addition, our restated certificate of incorporation provides that we must indemnify our directors and officers and we must advance expenses, including attorneys’ fees, to our directors and officers in connection with legal proceedings, subject to very limited exceptions.

We maintain a general liability insurance policy that covers specified liabilities of our directors and officers arising out of claims based on acts or omissions in their capacities as directors or officers. In addition, we have entered into indemnification agreements with our directors and executive officers. These indemnification agreements may require us, among other things, to indemnify each such executive officer or director for some expenses, including attorneys’ fees, judgments, fines and settlement amounts incurred by him or her in any action or proceeding arising out of his or her service as one of our executive officers or directors.

Some of our non-employee directors may, through their relationships with their employers, be insured or indemnified against specified liabilities incurred in their capacities as members of our Board of Directors.

Insofar as indemnification for liabilities arising under the Securities Act of 1933, as amended, or the Securities Act, may be permitted to directors, executive officers or persons controlling us, in the opinion of the Securities and Exchange Commission, such indemnification is against public policy as expressed in the Securities Act and is therefore unenforceable.

Rule 10b5-1 Sales Plans

Our directors and executive officers may adopt written plans, known as Rule 10b5-1 plans, in which they will contract with a broker to buy or sell shares of our common stock on a periodic basis. Under a Rule 10b5-1 plan, a broker executes trades pursuant to parameters established by the director or officer when entering into the plan, without further direction from the director or officer. It is also possible that the director or officer could amend or terminate the plan when not in possession of material, nonpublic information. In addition, our directors and executive officers may buy or sell additional shares outside of a Rule 10b5-1 plan when they are not in possession of material, nonpublic information.

Insider Trading Policy

We have adopted an Insider Trading Policy governing the purchase, sale and/or other dispositions of our securities by our directors, officers, employees, and other covered persons. We believe the Insider Trading Policy is reasonably designed to promote compliance with insider trading laws, rules and regulations, and Nasdaq listing standards. A copy of our Insider Trading Policy is filed as Exhibit 19.1 to our Annual Report on Form 10-K for the fiscal year ended December 31, 2024.

Our Insider Trading Policy expressly prohibits all of our employees, including our named executive officers, as well as our directors and certain of their family members and related entities, from engaging in short sales of our securities, including short sales “against the box”; purchases or sales of puts, calls or other derivative securities based on our securities and purchases of financial instruments (including prepaid variable forward contracts, equity swaps, collars and exchange funds) that are designed to hedge or offset any decrease in the market value of our securities.

Director Compensation

We do not pay any compensation to our President and Chief Executive Officer in connection with her service on our Board of Directors. Ms. Good is one of our named executive officers and, accordingly, the compensation that we pay to Ms. Good is discussed under “—Executive Compensation—2024 Summary Compensation Table” and “Executive Compensation—Narrative to Summary Compensation Table.”

Under our director compensation program, we pay our non-employee directors a cash retainer for service on the Board of Directors and for service on each committee on which the director is a member. The chairman of the board and the chairman of each committee receive higher retainers for such service. These fees are payable in arrears in four equal quarterly installments on the last day of each quarter, provided that the amount of such payment is prorated for any portion of such quarter that the director was not serving on our Board of Directors or on such committee. The fees paid to non-employee directors in 2024 as a retainer for service on the Board of Directors and for service on each committee of the Board of Directors on which the director was a member were as follows:

We also reimburse our non-employee directors for reasonable travel and out-of-pocket expenses incurred in connection with attending board of director and committee meetings.

In addition, under our director compensation program, each non-employee director elected or appointed to our Board of Directors receives upon his or her initial election or appointment to our Board of Directors an option to purchase shares of our common stock under our 2019 Plan. Each of these options vests as to 50% of the shares of our common stock underlying such option at the earlier of the first anniversary of the date of grant or the date of the first annual meeting of stockholders held following the date of grant, with the remainder vesting on the earlier of the second anniversary of the date of grant or the date of the second annual meeting of stockholders held following the date of grant, subject to the non-employee director’s continued service as a director, employee or consultant. Further, on the date of each annual meeting of stockholders, each non-employee director that has served on our Board of Directors for at least six months receives an option to purchase shares of our common stock under the 2019 Plan. Each of these options fully vests on the earlier of the first anniversary of the date of grant or the date of the next annual meeting of stockholders, subject to the non-employee director’s continued service as a director, employee or consultant. All options granted to our non-employee directors under our director compensation program are issued at exercise prices equal to the fair market value of our common stock on the date of grant and become exercisable in full in the event of a change in control.

In 2024, each non-employee director elected or appointed to our Board of Directors was eligible to receive upon his or her initial election or appointment to our Board of Directors an option to purchase 60,000 shares of our common stock under the 2019 Plan. Further, on the date of the 2024 Annual Meeting of Stockholders, each non-employee director was eligible to, and did receive, an option to purchase 30,000 shares of our common stock under the 2019 Plan.

The table below shows all compensation to our non-employee directors for the year ended December 31, 2024.

Effective February 18, 2025, we modified our director compensation program. Under the modified director compensation program, the option awards to be granted to our non-employee directors were increased. Under the modified director compensation program, each non-employee director elected or appointed to our Board of Directors will receive upon his or her initial election or appointment to our Board of Directors an option to purchase 90,000 shares of our common stock, and on the date of each annual meeting of stockholders, each non-employee director that has served on our Board of Directors for at least six months will receive an option to purchase 45,000 shares of our common stock. The vesting terms for both of these option grants remain unchanged.

EXECUTIVE COMPENSATION

The following discussion relates to the compensation of Jennifer Good, our President and Chief Executive Officer, James Cassella, Ph.D., our Chief Development Officer, and Lisa Delfini, our Chief Financial Officer. These individuals are collectively referred to in this proxy statement as our named executive officers.

2024 Summary Compensation Table

The following table sets forth information regarding compensation awarded to and earned by our named executive officers for the years ended December 31, 2024 and December 31, 2023:

Narrative to Summary Compensation Table

Base Salary. The base salary for our named executive officers is determined by our compensation committee or by our Board of Directors upon the recommendation of our compensation committee. Base salaries for our named executive officers typically are established through arms’ length negotiation at the time the named executive officer is hired, taking into account the position for which the named executive officer is being considered and the named executive officer’s qualifications, prior experience and salary expectations. In addition, on an annual basis, our compensation committee reviews and evaluates, with input from our Chief Executive Officer (other than with respect to herself), the need for adjustment of the base salaries of our named executive officers. Each determination as to base salary is based on the scope of each officer’s responsibilities along with his or her respective experience and, in the case of continuing officers, contributions to our company during the prior year. When reviewing base salaries, the compensation committee takes factors into account such as blended peer group and broader market data reviewed with the committee’s external compensation consultant, market competitiveness, expected future contribution, experience, impact and individual performance and internal parity relative to similar positions within our company, but does not assign any specific weighting

to any factor. In assessing executive base salaries against the blended peer group and broader market data, the compensation committee generally targets base salaries at the 50th percentile for each of the named executive officers with variation based on other factors such as tenure and scope of responsibilities. None of our named executive officers is currently party to an employment agreement or other agreement or arrangement that provides for automatic or scheduled increases in base salary.

The following table sets forth the annualized base salary for our named executive officers during the years ended December 31, 2024 and December 31, 2023:

Annual Bonus. The compensation committee or our Board of Directors upon the recommendation of our compensation committee may, in its discretion, award bonuses to our named executive officers. We typically establish annual bonus targets based on specified corporate goals for our named executive officers and conduct annual performance reviews to determine the attainment of such goals by each named executive officer. Bonus targets are generally established at the 50th percentile for each of our named executive officers. Our Chief Executive Officer may propose bonus awards to the compensation committee as part of this review process. The compensation committee or our Board of Directors upon the recommendation of our compensation committee makes the final determination of the eligibility requirements for and the amount of each bonus awarded to a named executive officer.

For 2024, the target annual bonus as a percentage of base salary was 55% for Ms. Good, 40% for Dr. Cassella and 40% for Ms. Delfini. For the 2024 bonus period, our Board of Directors established corporate performance goals, each having a designated weighting, which related to key development, strategic and financial goals of the company. In March 2025, our compensation committee met and evaluated the performance of the company against these performance goals and considered other achievements of the company. In light of the company’s performance against these goals and these achievements and factors, our compensation committee determined that we had achieved a corporate performance score of 110% and approved payment of a cash bonus for 2024 of $368,974 for Ms. Good, $53,666 for Dr. Cassella and $182,160 for Ms. Delfini. Dr. Cassella’s cash bonus was prorated for the time he was employed in 2024.

The stock options we have granted to our executive officers are typically subject to time-based vesting, although we have and may also grant stock options with performance-based vesting. The options with time-based vesting that we have granted to our executive officers typically become exercisable as to 25% of the shares underlying the option on the first anniversary of the grant date, and as to an additional 1/48th of the original number of shares underlying the option monthly thereafter. Vesting rights cease upon termination of employment and exercise rights cease shortly after termination, except that exercisability is extended in the case of death or disability and for options granted prior to July 14, 2017, vesting is fully accelerated upon a change of control. Prior to the exercise of an option, the holder has no rights as a stockholder with respect to the shares subject to such option, including no voting rights and no right to receive dividends or dividend equivalents.

The exercise prices of all stock options granted are equal to the fair market value of shares of our common stock on the date of grant determined by reference to the closing market price of our common stock on the date of grant.

In February 2024, we granted to Ms. Good and Ms. Delfini options with time-based vesting and options with performance-based vesting. Specifically, we granted to Ms. Good a time-based vesting option to purchase 630,000 shares of our common stock and a performance-based option to purchase 170,000 shares of our common stock and we granted to Ms. Delfini a time-based vesting option to purchase 175,000 shares of our common stock and a performance-based option to purchase 120,000 shares of our common stock. Ms. Good’s and Ms. Delfini’s time-based options vested with respect to 25% of the shares underlying the respective options on the one-year anniversary of the date of grant. The remaining 75% of the shares underlying the options are scheduled to vest in equal monthly installments thereafter through the remaining 36 months. The options with performance-based vesting that we granted to Ms. Good and Ms. Delfini in February 2024 were subject to vesting based on the timing and successful results of our Phase 2b clinical trial of Haduvio (nalbuphine ER) for the treatment of chronic cough in patients with idiopathic pulmonary fibrosis, which we refer to as the CORAL trial, and our Phase 2a clinical trial of Haduvio for the treatment of patients with refractory chronic cough, which we refer to as the RIVER trial. In March 2025, the compensation committee certified that the performance metrics related to the successful results of the RIVER trial were satisfied with respect to 80% of the performance-based options subject to the RIVER trial performance metrics, resulting in the vesting of the performance-based options granted to Ms. Good and Ms. Delfini as to 54,400 shares and 38,400 shares of common stock, respectively. The performance-based stock options granted to Ms. Good and Ms. Delfini remain eligible for vesting with respect to 102,000 and 72,000 additional shares of common stock underlying the respective options in the event that the performance metrics related to the successful results of the CORAL trial are satisfied.

In February 2025, our board of directors granted to our named executive officers options with time-based vesting, including to Ms. Good a stock option to purchase 811,000 shares of our common stock, to Dr. Cassella a stock option to purchase 257,500 shares of our common stock and to Ms. Delfini a stock option to purchase 225,500 shares of our common stock. These options are scheduled to vest with respect to 25% of the shares underlying the respective options on the one-year anniversary of the date of grant. The remaining 75% of the shares underlying the options are scheduled to vest in equal monthly installments thereafter through the remaining 36 months.

Role of our Compensation Committee. Our compensation committee reviews and approves, or recommends to our Board of Directors which approves, all compensation components including base salary, bonus, benefits, equity incentives and other perquisites, as well as severance arrangements, change-in-control benefits and other forms of compensation for our Chief Executive Officer and our other executive officers. In all cases, our compensation committee reviews executive compensation decisions with our Board of Directors before making a final determination. In addition, the compensation committee also considers matters related to individual compensation, such as compensation for new executive hires, as well as high-level strategic issues, such as the effectiveness of our compensation strategy, potential modifications to that strategy and new trends, plans, or approaches to compensation, at various meetings throughout the year. The compensation committee also reviews and approves the compensation of non-employee directors and has the authority to administer our equity-based plans.

Under its charter, our compensation committee may form and delegate authority to subcommittees consisting of independent directors, as it deems appropriate. Pursuant to the 2019 Plan, the compensation committee has delegated to our Chief Executive Officer the authority to approve grants of stock options to new hire employees below the level of Vice President, subject to specified limitations, including certain limitations for each level of employment and an annual aggregate maximum amount of awards that can be granted pursuant to such delegated authority.

The compensation committee meets regularly in executive session. However, from time to time, various members of management and other employees, as well as outside advisors or consultants, may be invited by the compensation committee to make presentations, to provide financial or other background information or advice, or to otherwise participate in compensation committee meetings. No officer may participate in, or be present during, any deliberations or determinations of the compensation committee regarding the compensation for such officer or any immediate family member of such officer. The charter of the compensation committee grants the compensation committee full access to all of our books, records, facilities and personnel, as well as authority to obtain, at our expense, advice and assistance from internal and external legal, accounting, or other advisors and consultants and other external resources that the compensation committee considers necessary or appropriate in the performance of its duties. In particular, the compensation committee may, in its sole discretion, retain compensation consultants to assist in its evaluation of executive and director compensation, including the authority to approve the consultant’s reasonable fees and other retention terms.

The compensation committee engaged Alpine Rewards, LLC, or Alpine, as its compensation consultant in mid-2023. Our compensation committee has considered the relationship that Alpine has with us, the members of our Board of Directors and our executive officers. Based on its evaluation, the compensation committee has determined that no conflicts of interest exist between the company and Alpine.

Alpine assisted the committee in conducting a competitive compensation assessment for our executive officers for the fiscal year ended December 31, 2024, including with respect to its determinations and recommendations with respect to base salary, target bonus, target bonus percentage and option grants. In setting or recommending the compensation for our executive officers in 2024, the

compensation committee, with the assistance of Alpine, reviewed and updated a peer group of publicly traded companies in the biopharmaceutical industry, which was comprised of companies whose market capitalization, number of employees, number of years as a public company, geographic region, maturity of product development pipeline and area of therapeutic focus are similar to ours.

Outstanding Equity Awards at December 31, 2024

The following table sets forth information regarding all outstanding stock options held by each of our named executive officers as of December 31, 2024. No unvested restricted stock awards were outstanding as of December 31, 2024.

Agreements with our Executive Officers

We have entered into employment agreements with each of our named executive officers.

Employment Agreement with Ms. Good

In December 2012, we and Ms. Good entered into an employment agreement. Under the agreement, Ms. Good is an “at will” employee, and her employment with us can be terminated by her or us at any time and for any reason. The agreement sets forth Ms. Good’s initial base salary, subject to adjustment from time to time and for any reason and provides that she is eligible, at the sole discretion of our Board of Directors, to earn an annual bonus of up to a specified percentage of her base salary. In September 2019, our Board of Directors approved our Executive Separation Benefits and Retention Plan, or Separation Benefits Plan, which superseded the terms of Ms. Good’s employment agreement pertaining to potential payments upon the termination of her employment in certain circumstances, including following a change in control. The Separation Benefits Plan is discussed below.

Offer Letter with Dr. Cassella

In September 2024, we and Dr. Cassella entered into an offer letter agreement. Under the agreement, Dr. Cassella is an “at will” employee, and his employment with us can be terminated by him or us at any time and for any reason. The offer letter sets forth Dr. Cassella’s initial base salary, subject to adjustment from time to time and for any reason, and provides that he is eligible, at the sole discretion of our Board of Directors, to earn an annual bonus of up to a specified percentage of his base salary. The offer letter also provides that Dr. Cassella is eligible for benefits pursuant to the Separation Benefits Plan, which is discussed below.

Offer Letter with Ms. Delfini

In June 2021, we and Ms. Delfini entered into an offer letter agreement. Under the agreement, Ms. Delfini is an “at will” employee, and her employment with us can be terminated by her or us at any time and for any reason. The offer letter sets forth Ms. Delfini’s initial base salary, subject to adjustment from time to time and for any reason, and provides that she is eligible, at the sole discretion of our Board of Directors, to earn an annual bonus of up to a specified percentage of her base salary. The offer letter also provides that Ms. Delfini is eligible for benefits pursuant to the Separation Benefits Plan, which is discussed below.

Employee Non-Competition, Non-Solicitation, Confidentiality and Assignment of Inventions Agreements

Each of our named executive officers has entered into standard form agreements with us with respect to non-competition, non-solicitation, confidential information and assignment of inventions. Under these agreements, each named executive officer has agreed not to compete with us during his or her employment and for a period ranging from one to two years after the termination of his or her employment, not to solicit our employees, independent contractors, clients, customers or business partners during his or her employment and for a period ranging from one to two years after the termination of his or her employment and to protect our confidential and proprietary information indefinitely.

Potential Payments upon Termination or Change in Control

In September 2019, the compensation committee of our Board of Directors adopted our Separation Benefits Plan. The Separation Benefits Plan applies to our Chief Executive Officer and our other officers, who we refer to collectively as our covered executives. Ms. Good, Dr. Cassella and Ms. Delfini are covered executives under the Separation Benefits Plan.

The Separation Benefits Plan provides for separation benefits in the event of (i) a termination of a covered executive’s employment by us other than for cause or by reason of such covered executive’s death or disability, or (ii) a resignation by such covered executive for good reason. Except as specifically provided in the Separation Benefits Plan, the separation benefits set forth in the Separation Benefits Plan supersede any separation benefits set forth in any award agreements and/or employment offer letters between us and any covered executive.

Under the terms of the Separation Benefits Plan, subject to the execution and effectiveness of a separation and release of claims agreement, if a covered executive’s employment is terminated by us other than for cause or by reason of such covered executive’s death or disability, or the covered executive resigns for good reason, in each case other than upon or within 12 months following a change in control (as defined in the Separation Benefits Plan), which we refer to as the CIC period, we will be obligated to:

Under the terms of the Separation Benefits Plan, subject to the execution and effectiveness of a severance and release of claims agreement, if, during the CIC period, a covered executive’s employment is terminated by us other than for cause (as defined in the Separation Benefits Plan) or by reason of such covered executive’s death or disability, or the covered executive resigns for good reason, we will be obligated to:

The Separation Benefits Plan is administered by our Board of Directors or our compensation committee. Our Board of Directors or our compensation committee may amend, modify, or terminate the Separation Benefits Plan at any time in its sole discretion; provided that (a) any such amendment, modification or termination made prior to a change in control that adversely affects the rights of any covered executive must be unanimously approved by our Board of Directors, including Ms. Good as Chief Executive Officer, (b) no such amendment, modification or termination may affect the rights of a covered executive then receiving payments or benefits under the Separation Benefits Plan without the consent of such covered executive, and (c) no such amendment, modification or termination made after a change in control will be effective for one year from the date of the change in control.

401(k) Retirement Plan

We maintain a defined contribution employee retirement plan for our employees, including our named executive officers. The plan is intended to qualify as a tax-qualified 401(k) plan so that contributions to the 401(k) plan and income earned on such contributions, are not taxable to participants until withdrawn or distributed from the 401(k) plan (except in the case of contributions under the 401(k) plan designated as Roth contributions). The 401(k) plan provides that we make non-discretionary matching contributions of 50% of the first 6% of elective contributions. Participants are immediately vested in their contributions, as well as any earnings thereon. Vesting in the employer match contribution portion of their accounts, as well as any earnings thereon, is based on years of credited service, vesting over a one-year period, with 100% vesting after one completed year.

Securities Authorized for Issuance under Equity Compensation Plans

The following table contains information about our equity compensation plans as of December 31, 2024. As of December 31, 2024, we had three equity compensation plans: our 2012 Stock Incentive Plan, as amended to date, or the 2012 Plan; the 2019 Plan; and our 2019 Employee Stock Purchase Plan, or the 2019 ESPP; each of which was approved by our stockholders.

Equity Compensation Plan Information

Pay Versus Performance

The Company is a smaller reporting company, and its most recent fiscal year ended December 31, 2024. As required by Item 402(v) of Regulation S-K, we are providing the following information regarding the relationship between executive compensation and our financial performance for each of the last two completed fiscal years. In determining the “compensation actually paid”, or CAP, to our NEOs, we are required to make various adjustments to amounts that have been previously reported in the Summary Compensation Table in previous years, as the SEC’s valuation methods for this section differ from those required in the Summary Compensation Table.

Analysis of the Information Presented in the Pay Versus Performance Table

TRANSACTIONS WITH RELATED PERSONS

Since January 1, 2023, we have engaged in the following transactions with our directors, executive officers and holders of 5% or more of our voting securities, and affiliates of our directors, executive officers and holders of 5% or more of our voting securities. We believe that all of these transactions were on terms as favorable as could have been obtained from unrelated third parties.

2024 Registered Offering

On December 17, 2024, we issued and sold 12,500,000 shares of our common stock to certain investors in an underwritten registered direct offering (the “December 2024 Offering”), at an offering price to investors of $4.00 per share of common stock pursuant to an underwriting agreement with Leerink Partners LLC, Stifel, Nicolaus & Company, Incorporated and Oppenheimer & Co. Inc, as representatives of the several underwriters. The December 2024 Offering resulted in aggregate gross proceeds to us of $50.0 million.

The following table sets forth the number of shares of our common stock that were issued and sold to certain of our 5% stockholders and their respective affiliates in the December 2024 Offering:

Registration Rights

We are a party to a second amended and restated investors’ rights agreement, which we refer to as the investors’ rights agreement, with certain of our 5% stockholders and their affiliates, as well as entities affiliated with some of our directors. This investors’ rights agreement provides these holders the right, subject to certain conditions, to demand that we file a registration statement or to request that their shares be covered by a registration statement that we are otherwise filing.

Indemnification Agreements

Our restated certificate of incorporation provides that we will indemnify our directors and officers to the fullest extent permitted by Delaware law. In addition, we have entered into indemnification agreements with all of our directors and executive officers.

Employment Agreements

See the “Executive Compensation—Agreements with our Executive Officers” section of this proxy statement for a further discussion of these arrangements.

Other Transactions

Jordyn Saradhi, the daughter of our Chief Executive Officer, has been employed as our Director, R&D Financial Operations since January 1, 2025. Prior to that, she was employed as the Director, FP&A and Accounting Operations from May 30, 2023 to December 31, 2024. From January 1, 2024 through December 31, 2024, Jordyn Saradhi was paid total compensation of $340,840 representing her base salary, the grant date fair value of stock awards granted to her and other compensation related to her employment by the company. From May 30, 2023 through December 31, 2023, Jordyn Saradhi was paid total compensation of $168,281 representing her base salary, the grant date fair value of stock awards granted to her and other compensation related to her employment by the company.

Policies and Procedures for Related Person Transactions

Our Board of Directors has adopted written policies and procedures for the review of any transaction, arrangement or relationship in which our company is a participant, the amount involved exceeds $120,000 and one of our executive officers, directors, director nominees or 5% stockholders, or their immediate family members, each of whom we refer to as a “related person,” has a direct or indirect material interest.

If a related person proposes to enter into such a transaction, arrangement or relationship, which we refer to as a “related person transaction,” the related person will be required to report the proposed related person transaction to our Chief Financial Officer and the chairman of our audit committee. The policy calls for the proposed related person transaction to be reviewed and, if deemed appropriate, approved by our audit committee. Whenever practicable, the reporting, review and approval will occur prior to entry into the proposed related person transaction. If advance review and approval is not practicable, the committee will review and in its discretion, may ratify the related person transaction. The policy also permits the chairman of the audit committee to review and if deemed appropriate, approve proposed related person transactions that arise between committee meetings, subject to ratification by the committee at its next meeting. Any related person transactions that are ongoing in nature will be reviewed annually.

A related person transaction reviewed under the policy will be considered approved or ratified if it is authorized by the audit committee after full disclosure of the related person’s interest in the transaction. As appropriate for the circumstances, the audit committee will review and consider:

Our audit committee may approve or ratify the transaction only if it determines that, under all of the circumstances, the transaction is in, or is not inconsistent with, our best interests. Our audit committee may impose any conditions on the related person transaction that it deems appropriate.

In addition to the transactions that are excluded by the instructions to the SEC’s related person transaction disclosure rule, our Board of Directors has determined that the following transactions do not create a material direct or indirect interest on behalf of related persons and therefore, are not related person transactions for purposes of this policy:

The policy provides that transactions involving compensation of executive officers will be reviewed and approved by our compensation committee in the manner specified in the compensation committee’s charter.

We did not have a written policy regarding the review and approval of related person transactions prior to our initial public offering. Nevertheless, with respect to such transactions, it has been the practice of our Board of Directors to consider the nature of and business reasons for such transactions, how the terms of such transactions compared to those which might be obtained from unaffiliated third parties and whether such transactions were otherwise fair to and in the best interests of, or not contrary to, our best interests.

PRINCIPAL STOCKHOLDERS

The following table sets forth information with respect to the beneficial ownership of our common stock as of April 23, 2025 by:

The column entitled “Percentage of Shares Beneficially Owned” is based on a total of 101,744,767 shares of our common stock outstanding as of April 23, 2025.

Beneficial ownership is determined in accordance with the rules and regulations of the SEC and includes voting or investment power with respect to our common stock. Shares of our common stock subject to options that are currently exercisable or exercisable within 60 days after April 23, 2025 are considered outstanding and beneficially owned by the person holding the options for the purpose of calculating the percentage ownership of that person but not for the purpose of calculating the percentage ownership of any other person. Except as otherwise noted, the persons and entities in this table have sole voting and investing power with respect to all of the shares of our common stock beneficially owned by them, subject to community property laws, where applicable. Except as otherwise set forth below, the address of each beneficial owner is c/o Trevi Therapeutics, Inc., 195 Church Street, 16th Floor, New Haven, Connecticut 06510.

* Less than one percent

REPORT OF THE AUDIT COMMITTEE

Our audit committee has reviewed our audited financial statements for the year ended December 31, 2024 and discussed them with our management and our independent registered public accounting firm, Ernst & Young LLP.

Our audit committee has also received from, and discussed with, Ernst & Young LLP various communications that Ernst & Young LLP is required to provide to our audit committee, including the matters required to be discussed by the applicable requirements of the Public Company Accounting Oversight Board and the Securities and Exchange Commission.

In addition, Ernst & Young LLP provided our audit committee with the written disclosures and the letter required by applicable requirements of the Public Company Accounting Oversight Board regarding the independent registered public accounting firm’s communications with the audit committee concerning independence and the audit committee has discussed with the company’s independent registered public accounting firm their independence.

Based on the review and discussions referred to above, our audit committee recommended to our Board of Directors that our financial statements audited by Ernst & Young LLP be included in our Annual Report on Form 10-K for the year ended December 31, 2024.

By the audit committee of the Board of Directors of Trevi Therapeutics, Inc.

Anne VanLent, Chairman

Dominick Colangelo

Michael Heffernan

HOUSEHOLDING

Some banks, brokers and other nominee stockholders of record may be participating in the practice of “householding” proxy statements, annual reports and notices of Internet availability of proxy materials. This means that only one copy of our documents, including the Notice, may have been sent to multiple stockholders in your household. We will promptly deliver a separate copy of any such document to you upon written or oral request to Trevi Therapeutics, Inc., 195 Church Street, 16th Floor, New Haven, CT 06510, Attention: Investor Relations, telephone: 203-304-2499. If you want to receive separate copies of our proxy statements, annual reports, or notices of Internet availability of proxy materials in the future, or if you are receiving multiple copies and would like to receive only one copy per household, you should contact your bank, broker or other nominee stockholders of record, or you may contact us at the above address and phone number.

STOCKHOLDER PROPOSALS

A stockholder who would like to have a proposal considered for inclusion in our 2026 proxy statement must submit the proposal in accordance with the procedures outlined in Rule 14a-8 of the Exchange Act so that it is received by us no later than January 2, 2026. However, if the date of the 2026 Annual Meeting of Stockholders is changed by more than 30 days from the date of the previous year’s annual meeting, then the deadline is a reasonable time before we begin to print and send our proxy statement for the 2026 Annual Meeting of Stockholders. SEC rules set standards for eligibility and specify the types of stockholder proposals that may be excluded from a proxy statement. Stockholder proposals should be addressed to Trevi Therapeutics, Inc., 195 Church Street, 16th Floor, New Haven, CT 06510, Attention: Investor Relations.

If a stockholder wishes to propose a nomination of persons for election to our Board of Directors or present a proposal at an annual meeting but does not wish to have the proposal considered for inclusion in our proxy statement, our amended and restated bylaws establish an advance notice procedure for such nominations and proposals. The required notice must be delivered by the stockholder and received by our corporate secretary at our principal executive offices and must otherwise meet the requirements set forth in our amended and restated bylaws, including the requirements of Rule 14a-19 under the Exchange Act, if the stockholder intends to comply with the SEC’s universal proxy rules and to solicit proxies in support of director nominees other than our nominees. Stockholders at an annual meeting may only consider proposals or nominations specified in the notice of the annual meeting or brought before the annual meeting by or at the direction of the Board of Directors or by a stockholder of record on the record date for the annual meeting, who is entitled to vote at the annual meeting and who has delivered timely notice in proper form to our corporate secretary of the stockholder’s intention to bring such business before the annual meeting.

The required notice must be in writing and received by our corporate secretary at our principal executive offices not less than 90 days nor more than 120 days prior to the first anniversary of the preceding year’s annual meeting. However, in the event that the date of the annual meeting is advanced by more than 30 days, or delayed by more than 60 days, from the first anniversary of the preceding year’s annual meeting, a stockholder’s notice must be so received no earlier than the 120th day prior to such annual meeting and not later than the close of business on the later of (A) the 90th day prior to such annual meeting and (B) the tenth day following the day on which notice of the date of such annual meeting was given or public disclosure of the date of such annual meeting was made, whichever first occurs. For stockholder proposals to be brought before the 2026 Annual Meeting of Stockholders, the required notice must be received by our corporate secretary at our principal executive offices no earlier than February 11, 2026 and no later than March 13, 2026; provided, however, that if the annual meeting is held earlier than May 12, 2026 or has not been held by August 10, 2026, then such notice must be received no later than the close of business on the later of (i) the 90th day prior to such annual meeting and (ii) the tenth day following the day on which notice of the date of such annual meeting was given or public disclosure of the date of such annual meeting was made, whichever first occurs.

OTHER MATTERS

Our Board of Directors does not know of any other matters to be brought before the Annual Meeting. If any other matters not mentioned in this proxy statement are properly brought before the Annual Meeting, the individuals named in the enclosed proxy intend to use their discretionary voting authority under the proxy to vote the proxy in accordance with their best judgment on those matters.

By Order of the Board of Directors

Jennifer Good

President and Chief Executive Officer

TREVI THERAPEUTICS, INC. 195 CHURCH STREET, 16TH FLOORNEW HAVEN, CT 06510 SCAN TO VIEW MATERIALS & VOTEw VOTE BY INTERNET Before The Meeting - Go to www.proxyvote.com or scan the QR Barcode above Use the Internet to transmit your voting instructions and for electronic delivery of information up until 11:59 p.m. Eastern Time on June 10, 2025. Have your proxy card in hand when you access the website and follow the instructions to obtain your records and to create an electronic voting instruction form. During The Meeting - Go to www.virtualshareholdermeeting.com/TRVI2025 You may attend the meeting via the Internet and vote during the meeting. Have the information that is printed in the box marked by the arrow available and follow the instructions. VOTE BY PHONE - 1-800-690-6903 Call to transmit your voting instructions up until 11:59 p.m. Eastern Time on June 10, 2025. Have your proxy card in hand when you call and then follow the instructions. VOTE BY MAIL Mark, sign and date your proxy card and return it in the postage-paid envelope we have provided or return it to Vote Processing, c/o Broadridge, 51 Mercedes Way, Edgewood, NY 11717. V72231-P29416TREVI THERAPEUTICS, INC. The Board of Directors recommends you vote FOR the following proposals 1-3: 1.Election of two Class III directors to our Board ofDirectors, each to serve until the 2028 Annual Meeting of Stockholders. Nominees: ForWithhold1a.Jennifer Good!! 1b.Anne VanLent!!ForAgainstAbstain 2.Ratification of the appointment of Ernst & Young LLP as our independent registered public accounting firm for the fiscal year ending !!! December 31, 2025. 3.Approval, on an advisory basis, of the compensation paid to our named executive officers.!!! The Board of Directors recommends you vote 1 YEAR on the following proposal 4:1 Year2 Years3 YearsAbstain 4.Approval, on an advisory basis, of the frequency of future advisory votes to approve the compensation paid to our named executive officers.!!!! The Board of Directors recommends you vote FOR the following proposal 5:ForAgainstAbstain 5.Approval of an amendment to the Trevi Therapeutics, Inc. 2019 Stock Incentive Plan to increase the number of shares available for issuance under the !!! plan by 6,000,000 shares of common stock, and make certain other amendments. NOTE: Transaction of any other business properly brought before the Annual Meeting or any adjournment or postponement of the Annual Meeting. Please sign exactly as your name(s) appear(s) hereon. When signing as attorney, executor, administrator, or other fiduciary, please give full title as such. Joint owners should each sign personally. All holders must sign. If a corporation or partnership, please sign in full corporate or partnership name by authorized officer. Important Notice Regarding the Availability of Proxy Materials for the Annual Meeting: The Notice and Proxy Statement and Form 10-K are available at www.proxyvote.com. V72232-P29416 TREVI THERAPEUTICS, INC. ANNUAL MEETING OF STOCKHOLDERS JUNE 11, 2025 1:00 PM EASTERN TIME THIS PROXY IS SOLICITED ON BEHALF OF THE BOARD OF DIRECTORS The stockholder(s) hereby appoint(s) Jennifer Good, Lisa Delfini, and Christopher Galletta, or any of them, as proxies, each with the power to appoint his or her substitute, and hereby authorize(s) them to represent and to vote, as designated on the reverse side of this ballot, all of the shares of Common Stock of TREVI THERAPEUTICS, INC. that the stockholder(s) is/are entitled to vote at the Annual Meeting of Stockholders to be held at 1:00 p.m. Eastern Time, on June 11, 2025, at www.virtualshareholdermeeting.com/TRVI2025, and any adjournment or postponement thereof. This proxy, when properly executed, will be voted in the manner directed herein. If no such direction is made, this proxy will be voted in accordance with the Board of Directors' recommendations. Continued and to be signed on reverse side

Appendix A

Plan Amendment

AMENDMENT NO. 1 TO

2019 STOCK INCENTIVE PLAN

OF

TREVI THERAPEUTICS, INC.

WHEREAS, Trevi Therapeutics, Inc. (the “Company”) maintains the 2019 Stock Incentive Plan (the “Plan”); and

WHEREAS, the Board of Directors of the Company has determined that it is in the best interest of the Company and its stockholders to amend the Plan, pursuant to Section 11(d) thereof, to (i) increase the number of shares of Company common stock that may be granted under the Plan and (ii) remove the annual increase in shares of Company common stock that may be granted under the Plan.

NOW, THEREFORE, in consideration of the foregoing, the Plan is amended, pursuant to Section 11(d) thereof, by replacing Section 4(a)(1) in its entirety with the following:

“(1) Authorized Number of Shares. Subject to adjustment under Section 9, Awards may be made under the Plan (any or all of which Awards may be in the form of Incentive Stock Options, as defined in Section 5(b)) for up to such number of shares of common stock, $0.001 par value per share, of the Company (the “Common Stock”) as is equal to the sum of:

(A) 21,000,000 shares of Common Stock; plus

(B) such additional number of shares of Common Stock (up to 11,000,000 shares) as is equal to the number of shares of Common Stock subject to awards granted under the Company’s 2012 Stock Incentive Plan, as amended, that were outstanding as of the effective date of the Plan and which awards expire, terminate or are otherwise surrendered, canceled, forfeited or repurchased by the Company at their original issuance price pursuant to a contractual repurchase right (subject, however, in the case of Incentive Stock Options, to any limitations under the Code).

Shares of Common Stock issued under the Plan may consist in whole or in part of authorized but unissued shares or treasury shares.”

Except as set forth above, all other terms of the Plan shall remain unchanged and in full force and effect.

Approved by the Board of Directors on April 24, 2025