Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Mar. 28, 2022	Jun. 30, 2021
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Annual Report	true
Document Period End Date	Dec. 31, 2021
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Document Transition Report	false
Entity File Number	001-37853
Entity Registrant Name	FIRST WAVE BIOPHARMA, INC.
Entity Central Index Key	0001604191
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	46-4993860
Entity Address, Address Line One	777 Yamato Road
Entity Address, Address Line Two	Suite 502
Entity Address, City or Town	Boca Raton
Entity Address, State or Province	FL
Entity Address, Postal Zip Code	33431
City Area Code	561
Local Phone Number	589-7020
Title of 12(b) Security	Common stock, par value $0.0001 per share
Trading Symbol	FWBI
Security Exchange Name	NASDAQ
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 Small Business	true
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	false
Entity Shell Company	false
Entity Public Float			$ 67.1
Entity Common Stock, Shares Outstanding		16,700,640
Auditor Firm ID	339
Auditor Name	Mazars USA LLP
Auditor Location	New York, NY