SEC Form DEFA14A filed by Avadel Pharmaceuticals plc

Step 1: Go to www.envisionreports.com/AVDL. Step 2: Click on Cast Your Vote or Request Materials. Step 3: Follow the instructions on the screen to log in. www.envisionreports.com/AVDL Online Go to www.envisionreports.com/AVDL or scan the QR code — login details are located in the shaded bar below. Shareholder Meeting Notice 045RSA Important Notice Regarding the Availability of Proxy Materials for the Avadel Pharmaceuticals plc Shareholder Meeting to be Held on July 29, 2025. Under Securities and Exchange Commission rules, you are receiving this notice that the proxy materials for the annual shareholders’ meeting are available on the Internet. Follow the instructions below to view the materials and vote online or request a copy. The items to be voted on and location of the annual meeting are on the reverse side. Your vote is important! This communication presents only an overview of the more complete proxy materials that are available to you on the Internet. We encourage you to access and review all of the important information contained in the proxy materials before voting. The 2025 Proxy Statement, 2024 Annual Report and 2024 Irish Statutory Financial Statements are available at: Obtaining a Copy of the Proxy Materials – If you want to receive a copy of the proxy materials, you must request one. There is no charge to you for requesting a copy. Please make your request as instructed on the reverse side on or before July 18, 2025 to facilitate timely delivery. 2NOT Easy Online Access — View your proxy materials and vote. When you go online, you can also help the environment by consenting to receive electronic delivery of future materials. The Sample Company Step 4: Make your selections as instructed on each screen for your delivery preferences. Step 5: Vote your shares. Votes submitted electronically must be received by 10:00 am Irish Standard Time on July 28, 2025. MMMMMMMMMMMM MMMMMMMMM 000001MR A SAMPLE DESIGNATION (IF ANY) ADD 1 ADD 2 ADD 3 ADD 4 ADD 5 ADD 6 ENDORSEMENT_LINE______________ SACKPACK_____________ 1234 5678 9012 345 C 1234567890 COY MMMMMMM

Here’s how to order a copy of the proxy materials and select delivery preferences: Current and future delivery requests can be submitted using the options below. If you request an email copy, you will receive an email with a link to the current meeting materials. PLEASE NOTE: You must use the number in the shaded bar on the reverse side when requesting a copy of the proxy materials. — Internet – Go to www.envisionreports.com/AVDL. Click Cast Your Vote or Request Materials. — Phone – Call us free of charge at 1-866-641-4276. — Email – Send an email to [email protected] with “Proxy Materials Avadel Pharmaceuticals plc” in the subject line. Include your full name and address, plus the number located in the shaded bar on the reverse side, and state that you want a paper copy of the meeting materials. To facilitate timely delivery, all requests for a paper copy of proxy materials must be received by July 18, 2025. The Avadel Pharmaceuticals plc Annual Meeting of Shareholders will be held on July 29, 2025, 10:00 AM (Irish Standard Time) at Ten Earlsfort Terrace, Dublin 2, D02 T380 Ireland. Proposals to be voted on at the meeting are listed below along with the Board of Directors’ recommendations. The Board of Directors recommends a vote FOR the election of each director nominee and FOR Proposal 2: 1. Election of Directors: 01 - Gregory J. Divis 02 - Dr. Eric J. Ende 03 - Geoffrey M. Glass 04 - Dr. Mark A. McCamish 05 - Linda S. Palczuk 06 - Peter J. Thornton 07 - Dr. Naseem S. Amin 2. To ratify, on a non-binding advisory basis, the appointment of Deloitte & Touche LLP as the Company’s independent registered public auditor and accounting firm for the fiscal year ending December 31, 2025, and to authorize, in a binding vote, the Audit Committee of the Board of Directors to set the independent registered public auditor and accounting firm remuneration The Board of Directors will consider and act upon any other business as may properly come before the meeting or any adjournment or postponement thereof. PLEASE NOTE – YOU CANNOT VOTE BY RETURNING THIS NOTICE. To vote your shares you must go online or request a paper copy of the proxy materials to receive a proxy card. If you wish to attend and vote at the meeting, please bring this notice with you. Shareholder Meeting Notice