| Record No. | Name | No. of Entries |
| 526 | N-Propargylnorapomorphine hydrochloride | 1 |
| 527 | N-Propionyldemecolcine | 1 |
| 528 | N-Propylnorapomorphine HCl | 1 |
| 529 | N-Trifluoroacetyldemecolcine | 1 |
| 530 | Nalbuphine | 5 |
| 531 | Nalorphine | 2 |
| 532 | Naltrexone | 1 |
| 533 | Nandazurine | 1 |
| 534 | Nantenine | 1 |
| 535 | Narcein | 2 |
| 536 | Narcophine | 1 |
| 537 | Narcotoline | 1 |
| 538 | NCGC00162160-01 | 1 |
| 539 | NCGC00180702-01 | 1 |
| 540 | NCGC00180968-01 | 1 |
| 541 | Nchembio.105-comp33 | 1 |
| 542 | Nchembio.2007.32-comp7 | 1 |
| 543 | Nchembio.78-comp20 | 1 |
| 544 | Neferine | 2 |
| 545 | Neoisocodeine | 1 |
| 546 | Neopine | 1 |
| 547 | Neopinone | 1 |
| 548 | Neuro_000455 | 1 |
| 549 | Nicocodine | 1 |
| 550 | Nicomorphine | 2 |