| Cover | Dec. 22, 2021 |
| Document Information [Line Items] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Dec. 22, 2021 |
| Entity File Number | 001-37759 |
| Entity Registrant Name | Outlook Therapeutics, Inc. |
| Entity Central Index Key | 0001649989 |
| Entity Tax Identification Number | 38-3982704 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 485 Route 1 South |
| Entity Address, Address Line Two | Building F |
| Entity Address, Address Line Three | Suite 320 |
| Entity Address, City or Town | Iselin |
| Entity Address, State or Province | NJ |
| Entity Address, Postal Zip Code | 08830 |
| City Area Code | 609 |
| Local Phone Number | 619-3990 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Common Stock [Member] | |
| Document Information [Line Items] | |
| Title of 12(b) Security | Common Stock |
| Trading Symbol | OTLK |
| Security Exchange Name | NASDAQ |
| Series A Warrants [Member] | |
| Document Information [Line Items] | |
| Title of 12(b) Security | Series A Warrants |
| Trading Symbol | OTLKW |
| Security Exchange Name | NASDAQ |
