| Document and Entity Information | Apr. 07, 2021 |
| Cover [Abstract] | |
| Security Exchange Name | NASDAQ |
| Amendment Flag | false |
| Entity Central Index Key | 0001780097 |
| Document Type | 8-K |
| Document Period End Date | Apr. 7, 2021 |
| Entity Registrant Name | Baudax Bio, Inc. |
| Entity Incorporation, State or Country Code | PA |
| Entity File Number | 001-39101 |
| Entity Tax Identification Number | 47-4639500 |
| Entity Address, Address Line One | 490 Lapp Road |
| Entity Address, City or Town | Malvern |
| Entity Address, State or Province | PA |
| Entity Address, Postal Zip Code | 19355 |
| City Area Code | (484) |
| Local Phone Number | 395-2470 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock, par value $0.01 |
| Trading Symbol | BXRX |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | true |
