| Document And Entity Information | Nov. 15, 2021 |
| Document Information [Line Items] | |
| Entity, Registrant Name | First Wave BioPharma, Inc. |
| Document, Type | 8-K |
| Document, Period End Date | Nov. 15, 2021 |
| Entity, Incorporation, State or Country Code | DE |
| Entity, File Number | 001-37853 |
| Entity, Tax Identification Number | 46-4993860 |
| Entity, Address, Address Line One | 777 Yamato Road, 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 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, par value $0.0001 per share |
| Trading Symbol | FWBI |
| Security Exchange Name | NASDAQ |
| Entity, Emerging Growth Company | true |
| Entity, Ex Transition Period | false |
| Amendment Flag | false |
| Entity, Central Index Key | 0001604191 |
