ProPhase Labs Inc美股招股说明书(2025-12-29版)

(To the Prospectus Dated November 20, 2024) Up to $5,289,599.84 of Shares of Common Stock(Par Value $0.0005 per share) ProPhase Labs, Inc. We have entered into a sales agreement (the “Sales Agreement”) with WestPark Capital, Inc. (“WestPark” or the “Sales Agent”)relating to shares of our common stock, $0.0005 par value per share, offered by this prospectus supplement and accompanying baseprospectus. In accordance with the terms of the Sales Agreement, we may offer and sell shares of our common stock from time to time Upon our delivery of a placement notice and subject to the terms and conditions of the Sales Agreement, the Sales Agent may sellshares of common stock by methods deemed to be an “at the market offering” as defined in Rule 415(a)(4) promulgated under theSecurities Act of 1933, as amended (the “Securities Act”). The Sales Agent will use its commercially reasonable efforts consistent with We will pay the Sales Agent a total commission for its services in acting as agent in the sale of common stock equal to 3.0% of thegross sales price per share of all shares sold through the Sales Agent as agent under the Sales Agreement. See “Plan of Distribution” In connection with the sale of common stock on our behalf, the Sales Agent will be deemed to be an “underwriter” within the meaningof the Securities Act and the compensation to the Sales Agent will be deemed to be underwriting commissions or discounts. We have In addition to sales of shares through or to the Sales Agent as described in this prospectus supplement, we may from time-to-timeissue, sell, or pledge a portion of the shares offered by this prospectus supplement as collateral to secure loan or credit facilities withthird-party lenders. Any such issuances or pledges will not exceed the aggregate dollar amount of securities registered under our shelfregistration statement and will be counted against the maximum limit of securities we are permitted to offer and sell under the “baby Our common stock is traded on The Nasdaq Capital Market tier of The Nasdaq Stock Market, LLC under the symbol “PRPH.” OnDecember 17, 2025, the last reported sale price of our common stock on The Nasdaq Capital Market was $0.11 per share. As of the date of this prospectus supplement, the aggregate market value of our outstanding common stock held by non-affiliates, orour public float, was approximately $30,208,445.51 based on 56,997,067 outstanding shares of common stock held by non-affiliatesand a per share price of $0.53, the closing price of our common stock on October 10, 2025, which is the highest closing sale price ofour common stock on the Nasdaq Capital Market within the prior 60 days. We have sold an aggregate of $4,779,882 of securities We are a smaller reporting company under Rule 405 of the Securities Act and, as such, have elected to comply with certain reducedpublic company reporting requirements for this prospectus, the documents incorporated by reference herein and future filings. INVESTINGIN OUR SECURITIES INVOLVES RISKS.WE STRONGLY RECOMMEND THAT YOU READCAREFULLY THE RISKS WE DESCRIBE IN THIS PROSPECTUS SUPPLEMENT AND THE ACCOMPANYING BASEPROSPECTUS, AS WELL AS THE RISK FACTORS THAT ARE INCORPORATED BY REFERENCE INTO THIS Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved thesecurities we may be offering or determined if this prospectus is accurate or complete. Any representation to the contrary is acriminal offense. WestPark Capital, Inc. The date of this prospectus supplement isDecember 29, 2025 ABOUT THIS PROSPECTUS SUPPLEMENT This prospectus supplement and the accompanying base prospectus relate to an “at the market offering” of shares of our commonstock. Before purchasing any shares of our common stock offered hereby, you should carefully read both this prospectus supplement On November 12, 2024, we filed with the U.S. Securities and Exchange Commission (the SEC) a registration statement on Form S-3(File No. 333-283182), utilizing a shelf registration process relating to the securities described in this prospectus supplement, whichregistration statement was declared effective on November 20, 2024. Under this shelf registration process, we may, from time to time, This document is in two parts. The first part is this prospectus supplement, which describes the specific terms of this “at the marketoffering” of common stock and also adds to and updates information contained in the accompanying base prospectus and thedocuments incorporated by reference into the base prospectus and this prospectus supplement. The second part, the accompanyingbase prospectus dated November 20, 2024, including the documents incorporated by reference therein, gives more general If the description of the offering varies between this prospectus supplement and the accompanying base prospectus, you should rely onthe information contained in this prospectus supplement. However, if any statement in one