| Document and Entity Information | Feb. 29, 2024 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Feb. 29, 2024 |
| Entity Registrant Name | SANA BIOTECHNOLOGY, INC. |
| Entity Central Index Key | 0001770121 |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
| Entity File Number | 001-39941 |
| Entity Incorporation, State or Country Code | DE |
| Entity Tax Identification Number | 83-1381173 |
| Entity Address, Address Line One | 188 East Blaine Street |
| Entity Address, Address Line Two | Suite 400 |
| Entity Address, City or Town | Seattle |
| Entity Address, State or Province | WA |
| Entity Address, Postal Zip Code | 98102 |
| City Area Code | 206 |
| Local Phone Number | 701-7914 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, $0.0001 par value per share |
| Trading Symbol | SANA |
| Security Exchange Name | NASDAQ |
