Company: GANX
Filing Date: 2025-07-15
Form Type: 424B5
Source: 0001104659-25-068103
Chunk: 12

Company: Gain Therapeutics, Inc.
Filing Date: 2025-07-15
Form: 424B5
Chunk 12
---
 stock issuable upon the exercise of such Pre-Funded Warrants.

Common Warrants offered by us pursuant to this prospectus supplement

Common Warrants to purchase an aggregate of , at the rate of one Common Warrant for every two shares of common stock or Pre-Funded Warrants purchased in this offering. The Common Warrants may only be exercisable for a whole number of shares of our common stock and, because the Underwriter will allocate purchases by investors in round lots comprised of an even number of shares and/or Pre-Funded Warrants, no fractional shares will be issued in this offering. Each Common Warrant has an exercise price of $ per share. The Common Warrants will be exercisable beginning on the date of issuance and expire on the fifth anniversary of the date of issuance. For more information, see the section titled “Description of Securities We Are Offering — Common Warrants.” This prospectus supplement also relates to the offering of the shares of common stock issuable upon the exercise of such Common Warrants.

Common stock to be outstanding after this offering

shares of common stock (or shares of common stock if the underwriter exercises its option to purchase additional securities), assuming the exercise in full of all Pre-Funded Warrants issued in this offering and no exercise of any of the Common Warrants.

<div align='center'>S-7</div>

TABLE OF CONTENTS

#### Option to purchase additional securities
We have granted to the underwriter the option, exercisable for 30 days from the date of this prospectus, to purchase up to additional shares of our common stock and/or Common Warrants to purchase additional shares of common stock, in each case at the public offering price, less underwriting discounts and commissions, to cover overallotments, if any.

#### Use of proceeds
We estimate that the net proceeds to us from this offering, after deducting estimated underwriting discounts and estimated offering expenses payable by us, will be approximately $ million and assuming no exercise of the Common Warrants (or approximately $ million if the underwriter exercises its option to purchase additional securities in full).

We intend to use the net proceeds of this offering to continue clinical and nonclinical development of our lead product candidate GT-02287 for the treatment of neurodegenerative diseases, including GBA1 Parkinson’s disease, and for general corporate purposes. See “Use of Proceeds” on page S-14of this prospectus supplement.

#### Risk factors
Investing in our securities involves risks. See the “Risk Factors” section of this