| Document and Entity Information - USD ($) | 12 Months Ended | | |
| Dec. 31, 2023 | Mar. 25, 2024 | Jun. 30, 2023 |
| Cover [Abstract] | | | |
| Document Type | 10-K/A | | |
| Amendment Flag | true | | |
| Amendment Description | In this Amendment No. 1 on Form 10-K/A (“Amendment No. 1”), unless the context requires otherwise, “Eledon”, the "Company", "we", "our", and "us" means Eledon Pharmaceuticals, Inc. (formerly Novus Therapeutics, Inc.) and all of its wholly-owned subsidiaries.This Amendment No. 1 amends the Annual Report on Form 10-K of Eledon Pharmaceuticals, Inc. for the fiscal year ended December 31, 2023, as filed with the Securities and Exchange Commission (the “SEC”) on March 28, 2024 (the “Original Report”). The Company is filing Amendment No. 1 to present the information required by Part III (Items 10, 11, 12, 13 and 14) of Form 10-K as we will not file our definitive proxy statement within 120 days of the end of our fiscal year ended December 31, 2023. In addition, in accordance with Rule 12b-15 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), Item 15 of Part IV of the Original Report is being amended and restated solely to include as exhibits the certifications of our principal executive officer and principal financial officer required by Rule 13a-14(a) under the Exchange Act. Except as otherwise expressly noted herein, this Amendment No. 1 does not amend, modify or update any other information set forth in the Original Report. Furthermore, this Amendment No. 1 does not change any previously reported financial results, nor does it reflect events occurring after the filing date of the Original Report. Information not affected by this Amendment No. 1 remains unchanged and reflects the disclosures made at the time the Original Report was filed. Accordingly, this Amendment No. 1 should be read in conjunction with the Original Report and our other filings with the SEC. Certain capitalized terms used and not otherwise defined in this Amendment No. 1 have the meanings given to them in the Annual Report. | | |
| Document Period End Date | Dec. 31, 2023 | | |
| Document Fiscal Year Focus | 2023 | | |
| Document Fiscal Period Focus | FY | | |
| Trading Symbol | ELDN | | |
| Entity Registrant Name | ELEDON PHARMACEUTICALS, INC. | | |
| Entity Central Index Key | 0001404281 | | |
| Current Fiscal Year End Date | --12-31 | | |
| Entity Well-known Seasoned Issuer | No | | |
| Entity Current Reporting Status | Yes | | |
| Entity Interactive Data Current | Yes | | |
| Entity Voluntary Filers | No | | |
| Entity Filer Category | Non-accelerated Filer | | |
| Entity Small Business | true | | |
| Document Financial Statement Error Correction [Flag] | false | | |
| Entity Shell Company | false | | |
| Entity Emerging Growth Company | false | | |
| Entity File Number | 001-36620 | | |
| Entity Tax Identification Number | 20-1000967 | | |
| Entity Address, Address Line One | 19900 MacArthur Boulevard | | |
| 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 | | |
| Entity Incorporation, State or Country Code | DE | | |
| Document Annual Report | true | | |
| Document Transition Report | false | | |
| ICFR Auditor Attestation Flag | false | | |
| Title of 12(b) Security | Common Stock, $0.001 par value | | |
| Security Exchange Name | NASDAQ | | |
| Entity Common Stock, Shares Outstanding | | 24,813,130 | |
| Entity Public Float | | | $ 25,607,310 |
| Documents Incorporated by Reference | DOCUMENTS INCORPORATED BY REFERENCE None | | |
