| Cover | Jan. 25, 2024 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Jan. 25, 2024 |
| Entity File Number | 001-41742 |
| Entity Registrant Name | SAGIMET BIOSCIENCES INC. |
| Entity Central Index Key | 0001400118 |
| Entity Tax Identification Number | 20-5991472 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 155 Bovet Road |
| Entity Address, Address Line Two | Suite 303 |
| Entity Address, City or Town | San Mateo |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 94402 |
| City Area Code | 650 |
| Local Phone Number | 561-8600 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Series A Common Stock, $0.0001 par value per share |
| Trading Symbol | SGMT |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | true |
| Elected Not To Use the Extended Transition Period | false |
