| Cover | Sep. 30, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Sep. 30, 2021 |
| Entity File Number | 001-36856 |
| Entity Registrant Name | Hepion Pharmaceuticals, Inc. |
| Entity Central Index Key | 0001583771 |
| Entity Tax Identification Number | 46-2783806 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 399 Thornall Street |
| Entity Address, Address Line Two | First Floor |
| Entity Address, City or Town | Edison |
| Entity Address, State or Province | NJ |
| Entity Address, Postal Zip Code | 08837 |
| City Area Code | 732 |
| Local Phone Number | 902-4000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock |
| Trading Symbol | HEPA |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | true |
| Elected Not To Use the Extended Transition Period | true |
