| Document and Entity Information | Jan. 24, 2024 |
| Document And Entity Information [Line Items] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001828522 |
| Document Type | 8-K |
| Document Period End Date | Jan. 24, 2024 |
| Entity Registrant Name | eFFECTOR Therapeutics, Inc. |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-39866 |
| Entity Tax Identification Number | 85-3306396 |
| Entity Address, Address Line One | 142 North Cedros Avenue |
| Entity Address, Address Line Two | Suite B |
| Entity Address, City or Town | Solana Beach |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 92075 |
| City Area Code | (858) |
| Local Phone Number | 925-8215 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
| Common Stock 0.0001 Par Value Per Share 2 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Common stock, $0.0001 par value per share |
| Trading Symbol | EFTR |
| Security Exchange Name | NASDAQ |
| Warrants To Purchase Common Stock 1 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Warrants to purchase common stock |
| Trading Symbol | EFTRW |
| Security Exchange Name | NASDAQ |
