| Systematic (IUPAC) name | |
|---|---|
| (8R,9S,10R,13S,14S)-13-Methyl-1,2,6,7,8,9,10,11,12,14,15,16-dodecahydrocyclopenta[a]phenanthrene-3,17-dione | |
| Clinical data | |
| Pregnancy cat. | ? |
| Legal status | Schedule III (US) |
| Routes | Oral |
| Identifiers | |
| CAS number | 734-32-7 |
| ATC code | ? |
| PubChem | CID 92834 |
| DrugBank | DB01434 |
| ChemSpider | 83803 |
| Chemical data | |
| Formula | C18H24O2 |
| Mol. mass | 272.38 g/mol |
| SMILES | eMolecules & PubChem |
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19-Norandrostenedione (4-estrene-3,17-dione, NOR) is a precursor of the anabolic steroid nandrolone. Until 2005 19-Norandrostenedione was available without prescription in United States, where it was marketed as a prohormone, but it is now classified as a Schedule III drug. 19-Norandrostenedione is readily metabolized to nandrolone after oral administration, but its potency to transactivate the androgen receptor dependent reporter gene expression is 10 times lower as compared to dihydrotestosterone (DHT).[1]
Scientific studies have shown that oral administration of 19-norandrostenedione is "a very ineffective strategy for stimulating skeletal muscle mass increases but may be associated with side effects".[2]
In vivo experiments in castrated rats demonstrated that subcutaneous treatment with 19-norandrostenedione resulted only in a stimulation of the weight of the levator ani muscle, while the prostate and seminal vesicle weights remained completely unaffected. In contrast to its metabolite nandrolone, 19-norandrostenedione highly selectively stimulates the growth of the skeletal muscles but has only weak androgenic properties.[1]
In the early 2000s, contamination of androstenedione products with traces of 19-norandrostenedione caused false positives for doping tests for nandrolone because 19-norandrosterone is a metabolite of both nandrolone and 19-norandrostenedione. In a randomized controlled trial trace contamination of androstenedione with 19-norandrostenedione was sufficient for users of androstendione to test positive for nandrolone.[3] This detail became less relevant after androstenedione itself was banned by major sporting bodies.