RESEARCH MONOGRAPH · KDC-MN-393
Nandrolone
Nandrolone (19-nortestosterone) is the parent of an entire class of anabolic steroids defined by the missing 19-carbon. That single deletion does two useful things: it reduces aromatization to estrogen and it prevents 5-alpha-reduction from making a more potent metabolite. Instead, 5-alpha-reduction in skin and other tissues yields dihydronandrolone, which has lower AR affinity than the parent, so androgenic side effects are blunted. The decanoate ester (Deca-Durabolin) gives a 14-day half-life IM; phenylpropionate is faster (3 to 4 days). Approved for anemia of kidney disease and historically for osteoporosis. Schedule III. Heavy non-medical use in bodybuilding for lean mass and (anecdotally) joint support. Sexual dysfunction with prolonged use is attributed to progestogenic metabolites. Canonical 19-nor AAS. Not stocked by Kodiac. This monograph is provided for research and educational reference.
Intrigue 0–100 blends mechanism novelty, evidence strength, and translational potential. Kodiac editorial, not peer-reviewed.
19-nortestosterone (parent of nandrolone class)
19-nortestosterone; the parent compound of the nandrolone class of AAS; the decanoate ester is approved for anemia and osteoporosis.
Abstract
Nandrolone (17-beta-hydroxyestr-4-en-3-one; CAS 434-22-0; molecular formula C18H26O2; molecular weight 274.40) is the parent compound of the 19-nortestosterone (nandrolone) class of AAS; the 19-nor modification reduces aromatization to estrogen and prevents 5-alpha-reduction to a more potent metabolite. The compound itself binds AR with affinity approximately 5-fold higher than testosterone but with reduced effects in some tissues (5-alpha-reduction by 5-AR produces dihydronandrolone, which has lower AR affinity than nandrolone, in contrast to testosterone-DHT relationship; the result is reduced androgenic side effects). The decanoate ester (Deca-Durabolin) provides a 14-day half-life for IM administration; the phenylpropionate ester provides a shorter (3 to 4 day) half-life. Approved for anemia of chronic kidney disease and (historically) osteoporosis. Schedule III. Widely used in non-medical bodybuilding for lean mass gains and (anecdotally) joint support. The "deca dick" sexual dysfunction is attributed to the progestogenic activity of nandrolone metabolites. Used as the canonical 19-nor AAS in research.
Mechanism of action
19-nortestosterone parent compound; AR agonism with reduced 5-alpha-reduction potency and reduced aromatization. Progestogenic metabolite activity.
Reported research dose ranges
Reported research dose ranges vary across the published literature.
References
- Kicman AT. Pharmacology of anabolic steroids. Br J Pharmacol 2008.
- Hartgens F, Kuipers H. Effects of androgenic-anabolic steroids in athletes. Sports Med 2004.
- Mosby's Drug Reference. Nandrolone decanoate. 2018.
Read the full monograph
Available as a research-use-only PDF download.
The full reference document is provided strictly for research use only. It reports research dose ranges from the published literature, not instructions for use in humans or animals.
FOR RESEARCH USE ONLY. Not for medical, diagnostic, or therapeutic purposes. Not for human consumption. All information is provided for research and educational purposes only.