| Document and Entity Information | Sep. 13, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Sep. 13, 2021 |
| Entity Registrant Name | ELIEM THERAPEUTICS, INC. |
| Entity Central Index Key | 0001768446 |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
| Entity File Number | 001-40708 |
| Entity Incorporation, State or Country Code | DE |
| Entity Tax Identification Number | 83-2273741 |
| Entity Address, Address Line One | 23515 NE Novelty Hill Road |
| Entity Address, Address Line Two | Suite B221 #125 |
| Entity Address, City or Town | Redmond |
| Entity Address, State or Province | WA |
| Entity Address, Postal Zip Code | 98053 |
| City Area Code | 425 |
| Local Phone Number | 276-2300 |
| Title of 12(b) Security | Common Stock, par value $0.0001 per share |
| Trading Symbol | ELYM |
| Security Exchange Name | NASDAQ |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
