| Product Name | CAS Registry Number |
| Resorcine | 108-46-3 |
| Resorcinol sulfide | 97-29-0 |
| Resveratrol | 501-36-0 |
| Retinol palmitate | 79-81-2 |
| Retinyl acetate | 127-47-9 |
| Rhamnetin | 90-19-7 |
| Rhein | 478-43-3 |
| Rhodamine B | 81-88-9 |
| Rhodanine | 141-84-4 |
| Rhodanine-3-acetic acid | 5718-83-2 |