Trevi Therapeutics, Inc.

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, 16 th 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.