Annual report pursuant to Section 13 and 15(d)

Document and Entity Information

Document and Entity Information - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2021
Mar. 16, 2022
Jun. 30, 2021
Document and Entity Information      
Document Type 10-K    
Document Period End Date Dec. 31, 2021    
Document Annual Report true    
Document Transition Report false    
Entity File Number 001-12584    
Entity Registrant Name Synthetic Biologics, Inc.    
Entity Incorporation, State or Country Code NV    
Entity Tax Identification Number 13-3808303    
Entity Address, Address Line One 9605 Medical Center Drive, Ste. 270    
Entity Address, City or Town Rockville    
Entity Address, Country MD    
Entity Address, Postal Zip Code 20850    
City Area Code 301    
Local Phone Number 417-4364    
Title of 12(b) Security Common Stock    
Trading Symbol SYN    
Security Exchange Name NYSE    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Non-accelerated Filer    
Entity Small Business true    
Entity Emerging Growth Company false    
Entity Shell Company false    
Entity Common Stock, Shares Outstanding   158,437,840  
Entity Central Index Key 0000894158    
Current Fiscal Year End Date --12-31    
Document Fiscal Year Focus 2021    
Document Fiscal Period Focus FY    
Amendment Flag false    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Public Float     $ 79.2
ICFR Auditor Attestation Flag false    
Auditor Name BDO USA, LLP    
Auditor Firm ID 243    
Auditor Location Potomac, Maryland