v3.26.1
Document and Entity Information
 12 Months Ended
Dec. 31, 2025
shares
Document Information [Line Items]  
Document Type 20-F
Document Registration Statement false
Document Annual Report true
Document Period End Date Dec. 31, 2025
Document Transition Report false
Document Shell Company Report false
Entity File Number 001-39179
Entity Registrant Name Addex Therapeutics Ltd
Entity Incorporation, State or Country Code V8
Entity Address, Address Line One Chemin des Mines 9
Entity Address, Address Line Two CH
Entity Address, Postal Zip Code 1202
Entity Address, City or Town Geneva
Entity Address, Country CH
Entity Common Stock, Shares Outstanding 147,831,814
Entity Well-known Seasoned Issuer No
Entity Voluntary Filers No
Entity Current Reporting Status Yes
Entity Interactive Data Current Yes
Entity Filer Category Non-accelerated Filer
Entity Emerging Growth Company false
ICFR Auditor Attestation Flag false
Document Accounting Standard International Financial Reporting Standards
Entity Shell Company false
Entity Central Index Key 0001574232
Amendment Flag false
Current Fiscal Year End Date --12-31
Document Fiscal Year Focus 2025
Document Fiscal Period Focus FY
Auditor Name BDO AG
Auditor Location Zurich, Switzerland
Auditor Firm ID 5988
Document Financial Statement Error Correction [Flag] false
Common shares  
Document Information [Line Items]  
Title of 12(b) Security Shares, par value CHF 0.01 per share
No Trading Symbol Flag true
American Depositary Shares  
Document Information [Line Items]  
Title of 12(b) Security American Depositary Shares
Trading Symbol ADXN
Security Exchange Name NASDAQ
Business Contact [Member]  
Document Information [Line Items]  
Entity Address, Address Line One Chemin des Mines 9
Entity Address, Address Line Two CH
Entity Address, Postal Zip Code 1202
Entity Address, City or Town Geneva
Entity Address, Country CH
Contact Personnel Name Tim Dyer
Country Region 41
City Area Code 22
Local Phone Number 884 1555