19-Norandrostenedione

19-Norandrostenedione

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
Routes of administration	Oral
Legal status	Schedule III (US)
Identifiers
CAS Number	734-32-7
PubChem	CID 92834
DrugBank	DB01434
ChemSpider	83803
UNII	U90987PVU5
Chemical data
Formula	C18H24O2
Molar mass	272.38 g/mol
SMILES O=C4/C=C3/CC[C@@H]2[C@H](CC[C@@]1(C(=O)CC[C@H]12)C)[C@H]3CC4
InChI InChI=1S/C18H24O2/c1-18-9-8-14-13-5-3-12(19)10-11(13)2-4-15(14)16(18)6-7-17(18)20/h10,13-16H,2-9H2,1H3/t13-,14+,15+,16-,18-/m0/s1 Key:JRIZOGLBRPZBLQ-QXUSFIETSA-N
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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. It is also banned from use in many sports, including the Olympic Games, under the World Anti-Doping Code.^[1] 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).^[2]

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".^[3]

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.^[2]

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.^[4] This detail became less relevant after 19-norandrostenedione and androstenedione were banned by major sporting bodies.

See also

• selective androgen receptor modulator

References

1. "The World Anti-Doping Code: The 2012 Prohibited List" (PDF). World Anti-Doping Agency. Retrieved 2012-07-16.
2. Diel P, Friedel A, Geyer H, Kamber M, Laudenbach-Leschowsky U, Schänzer W, Schleipen B, Thevis M, Vollmer G, Zierau O (April 2008). "The prohormone 19-norandrostenedione displays selective androgen receptor modulator (SARM) like properties after subcutaneous administration". Toxicol. Lett. 177 (3): 198–204. doi:10.1016/j.toxlet.2008.01.014. PMID 18325697.
3. Parr, MK; Laudenbach-Leschowsky, U; Höfer, N; Schänzer, W; Diel, P (2009). "Anabolic and androgenic activity of 19-norandrostenedione after oral and subcutaneous administration--analysis of side effects and metabolism". Toxicology letters 188 (2): 137–41. doi:10.1016/j.toxlet.2009.03.024. PMID 19446246.
4. Catlin DH, Leder BZ, Ahrens B, Starcevic B, Hatton CK, Green GA, Finkelstein JS (2000). "Trace contamination of over-the-counter androstenedione and positive urine test results for a nandrolone metabolite". JAMA 284 (20): 2618–21. doi:10.1001/jama.284.20.2618. PMID 11086369.