Trevi Therapeutics Inc美国存托凭证发行说明书（2025年6月2日版）

SUBJECT TO COMPLETION, DATED JUNE2, 2025 PRELIMINARY PROSPECTUS SUPPLEMENT(To Prospectus dated August15, 2023) We are offering $100,000,000 of shares of our common stock in this offering. Our common stock is listed on the Nasdaq Global Market under the symbol “TRVI.” The lastreported sale price for our common stock on May30, 2025, was $6.51 per share. We are a “smaller reporting company” under applicable Securities and Exchange Commission, or theSEC, rules and, as such, have elected to comply with certain reduced public company disclosurerequirementsfor this prospectus supplement and future filings.See“Prospectus Supplement Investing in our securities involves significant risks. See “Risk Factors” beginning on pageS-8of thisprospectus supplement and in our filings with the Securities and Exchange Commission that areincorporated by reference in this prospectus supplement to read about factors you should consider Offering priceUnderwriting discounts and commissions(1) (1)We have agreed to reimburse the underwriters for certain offering-related expenses. See “Underwriting” beginning onpage S-18 for additional information regarding these expenses and the underwriting discounts and commissions payable inthis offering. We have granted the underwriters an option for a period of 30 days to purchase up to an additional $15,000,000 of shares of ourcommon stock at the public offering price per share of common stock, less underwriting discounts and commissions. If theunderwriters exercise their option in full, the total underwriting discounts and commissions payable by us will be $, The information in this preliminary prospectus supplement is not complete and may be changed. A registration statement relating to these securities has been declaredeffective by the Securities and Exchange Commission. This preliminary prospectus supplement and the accompanying prospectus are not an offer to sell these securitiesand we are not soliciting an offer to buy these securities in any state or jurisdiction where the offer or sale is not permitted.Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of thesesecurities or passed upon the accuracy or adequacy of this prospectus supplement or the accompanying prospectus. Anyrepresentation to the contrary is a criminal offense. The underwriters expect to deliver the shares of common stock to investors on or about June Joint Book-Running Managers MORGANSTANLEY STIFELCANTOR Table of Contents ABOUT THIS PROSPECTUS SUPPLEMENT This document is in two parts. The first part is this prospectus supplement, which describes the specific terms of this offering and also adds to andupdates information contained in the accompanying prospectus and the documents incorporated by reference herein and therein. The second part, theaccompanying prospectus, provides more general information about our business and our securities. Generally, when we refer to this prospectus, we arereferring to both parts of this document combined. To the extent there is a conflict between the information contained in this prospectus supplement, onthe one hand, and the information contained in the accompanying prospectus or any document incorporated by reference herein or therein filed before Before buying any of the securities that we are offering, we urge you to carefully read this prospectus supplement and the accompanyingprospectus, all of the information contained in the documents incorporated by reference in this prospectus supplement and the accompanying prospectus, We further note that the representations, warranties and covenants made by us in any agreement that is filed as an exhibit to any document that isincorporated by reference herein were made solely for the benefit of the parties to such agreement, including, in some cases, for the purpose of We have not authorized, and the underwriters have not authorized, anyone to provide you with any information other than that contained orincorporated by reference in this prospectus supplement, the accompanying prospectus or in any free writing prospectus that we authorize for use inconnection with this offering and to which we have referred you. We and the underwriters take no responsibility for and can provide no assurance as tothe reliability of, any other information that others may give you. This prospectus supplement and the accompanying prospectus do not constitute an Other than in the United States, no action has been taken by us or the underwriters that would permit an offering of the securities offered by thisprospectus supplement and the accompanying prospectus in any jurisdiction where action for that purpose is required. The securities offered by thisprospectus supplement and the accompanying prospectus may not be offered or sold, directly or indirectly, nor may this prospectus supplement, theaccompanying prospectus or any other offering material or advertisements in connection with the