| Cover | Feb. 02, 2023 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Feb. 02, 2023 |
| Entity File Number | 000-56228 |
| Entity Registrant Name | IANTHUS CAPITAL HOLDINGS, INC. |
| Entity Central Index Key | 0001643154 |
| Entity Tax Identification Number | 98-1360810 |
| Entity Incorporation, State or Country Code | A1 |
| Entity Address, Address Line One | 420 Lexington Avenue |
| Entity Address, Address Line Two | Suite 414 |
| Entity Address, City or Town | New York |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 10170 |
| City Area Code | 646 |
| Local Phone Number | 518-9418 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | true |
| Elected Not To Use the Extended Transition Period | false |
