| Document and Entity Information | Jan. 13, 2020 |
| Cover [Abstract] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001438533 |
| Document Type | 8-K |
| Document Period End Date | Jan. 13, 2020 |
| Entity Registrant Name | RETROPHIN, INC. |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-36257 |
| Entity Tax Identification Number | 27-4842691 |
| Entity Address, Address Line One | 3721 Valley Centre Drive |
| Entity Address, Address Line Two | Suite 200 |
| Entity Address, City or Town | San Diego |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 92130 |
| City Area Code | (888) |
| Local Phone Number | 969-7879 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock, par value $0.0001 per share |
| Trading Symbol | RTRX |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
