Company: GANX
Filing Date: 2025-11-28
Form Type: 424B5
Source: 0001104659-25-116944
Chunk: 25

Company: Gain Therapeutics, Inc.
Filing Date: 2025-11-28
Form: 424B5
Chunk 25
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000,000. This prospectus provides you with a general description of the securities we may offer. When we issue securities pursuant to this prospectus, we will provide a prospectus supplement that will contain specific information about the terms of that offering. The prospectus supplement may also add, update or change information contained in this prospectus. You should read both this prospectus and any prospectus supplement together with additional information described under the heading “Additional Information” and “Incorporation of Certain Information by Reference.”

Gain Therapeutics, Inc. is referred to herein as “Gain,” “the Company,” “we,” “us,” and “our,” unless the context indicates otherwise.

You may only rely on the information contained in or incorporated by reference in this prospectus, and any accompanying prospectus supplement or in any free writing prospectus prepared by or on behalf of us or to which we have referred you. We have not authorized anyone to provide you with different information. This prospectus and any prospectus supplement do not constitute an offer to sell or a solicitation of an offer to buy any securities other than the securities offered by this prospectus or such accompanying prospectus supplement. This prospectus and any prospectus supplement do not constitute an offer to sell or a solicitation of an offer to buy any securities in any circumstances in which such offer or solicitation is unlawful. Neither the delivery of this prospectus or any prospectus supplement nor any sale made hereunder shall, under any circumstances, create any implication that there has been no change in our affairs since the date of this prospectus or such prospectus supplement or that the information incorporated by reference to this prospectus or any prospectus supplement is correct as of any time after its date.

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TABLE OF CONTENTS

### PROSPECTUS SUMMARY
The following summary highlights some information from this prospectus. It is not complete and does not contain all of the information that you should consider before making an investment decision. You should read this entire prospectus, including the “Risk Factors” section on page 4 and the disclosures to which that section refers you, the financial statements and related notes and the other more detailed information appearing elsewhere or incorporated by reference into this prospectus before investing in any of the securities described in this prospectus.

### Overview
We are a biotechnology company developing novel small molecule therapeutics to treat diseases across several therapeutic areas, including, central nervous system (“CNS”) disorders, lysosomal storage disorders (“LSDs”), metabolic