| Document And Entity Information | Apr. 26, 2023 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Apr. 26, 2023 |
| Entity Registrant Name | Eledon Pharmaceuticals, Inc. |
| Entity Central Index Key | 0001404281 |
| Entity Emerging Growth Company | false |
| Securities Act File Number | 001-36620 |
| Entity Incorporation, State or Country Code | DE |
| Entity Tax Identification Number | 20-1000967 |
| Entity Address, Address Line One | 19900 MacArthur Blvd. |
| Entity Address, Address Line Two | Suite 550 |
| Entity Address, City or Town | Irvine |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 92612 |
| City Area Code | 949 |
| Local Phone Number | 238-8090 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, $0.001 par value |
| Trading Symbol | ELDN |
| Security Exchange Name | NASDAQ |
