| Document and Entity Information | Aug. 11, 2021 |
| Document and Entity Information [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Aug. 11, 2021 |
| Entity File Number | 001-40237 |
| Entity Registrant Name | Gain Therapeutics, Inc. |
| Entity Incorporation, State or Country Code | DE |
| Entity Tax Identification Number | 85-1726310 |
| Entity Address, Address Line One | 4800 Hampden Lane |
| Entity Address, Adress Line Two | Suite 200 |
| Entity Address, City or Town | Bethesda |
| Entity Address, State or Province | MD |
| Entity Address, Postal Zip Code | 20814 |
| City Area Code | 301 |
| Local Phone Number | 500-1556 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, $0.0001 par value |
| Trading Symbol | GANX |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | true |
| Entity Central Index Key | 0001819411 |
| Amendment Flag | false |
