v3.26.1
Document and Entity Information - shares
 3 Months Ended
Mar. 31, 2026
Apr. 30, 2026
Document and Entity Information [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Mar. 31, 2026  
Document Transition Report false  
Securities Act 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 Montgomery Lane  
Entity Address, Address Line Two Suite 220  
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  
Title of 12(b) Security Common Stock, par value $0.0001 per share  
Trading Symbol GANX  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Non-accelerated Filer  
Entity Small Business true  
Entity Emerging Growth Company true  
Entity Ex Transition Period false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   42,654,038
Entity Central Index Key 0001819411  
Current Fiscal Year End Date --12-31  
Document Fiscal Year Focus 2026  
Document Fiscal Period Focus Q1  
Amendment Flag false