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5α-Dihydronandrolone (also known as 5α-DHN, dihydronandrolone, DHN, 5α-dihydro-19-nortestosterone, or 5α-estran-17β-ol-3-one) is a naturally occurring anabolic–androgenic steroid (AAS) and a 5α-reduced derivative of nandrolone (19-nortestosterone).[1] It is a major metabolite of nandrolone and is formed from it by the actions of the enzyme 5α-reductase analogously to the formation of dihydrotestosterone (DHT) from testosterone.[1][2]

Clinical data
Other namesDihydronandrolone; DHN; 5α-DHN; 5α-Dihydro-19-nortestosterone; 5α-Estran-17β-ol-3-one; 19-nor-5α-androstan-17β-ol-3-one
CAS Number
PubChem CID
Chemical and physical data
Molar mass276.42 g/mol g·mol−1
3D model (JSmol)

When testosterone is 5α-reduced into DHT, which is a much more potent AAS in comparison, its effects are potentiated on a local level.[1][2] The tissues in which this occurs (i.e., the tissues that express 5α-reductase) are referred to as "androgenic" tissues and include the skin, hair follicles, and prostate gland, among others.[1] The conversion of testosterone into DHT is an important factor in the etiology of a variety of androgen-dependent conditions, including acne, excessive facial/body hair growth, scalp hair loss, prostate enlargement, and prostate cancer.[1] Unlike the case of testosterone and DHT, 5α-DHN is a much weaker agonist of the androgen receptor (AR) than is nandrolone.[1][2][3][4] For this reason, instead of local potentiation in androgenic tissues, there is a local inactivation when nandrolone is converted into 5α-DHN by 5α-reductase in these tissues.[1][2][3] This is thought to be largely or completely responsible for the exceptionally high ratio of anabolic to androgenic effects seen with nandrolone.[1][2]

The combination of nandrolone with a 5α-reductase inhibitor like finasteride or dutasteride will block the conversion of nandrolone into 5α-DHN and, unlike with testosterone and various other AAS, thereby considerably increase the propensity of nandrolone for producing androgenic side effects.[3]

Relative affinities of nandrolone and related steroids at the androgen receptor

Compound rAR (%) hAR (%)
Testosterone 38 38
5α-Dihydrotestosterone 77 100
Nandrolone 75 92
5α-Dihydronandrolone 35 50
Ethylestrenol ND 2
Norethandrolone ND 22
5α-Dihydronorethandrolone ND 14
Metribolone 100 110
Sources: See template.

See alsoEdit


  1. ^ a b c d e f g h Kicman AT (June 2008). "Pharmacology of anabolic steroids". British Journal of Pharmacology. 154 (3): 502–21. doi:10.1038/bjp.2008.165. PMC 2439524. PMID 18500378.
  2. ^ a b c d e John A. Thomas (6 December 2012). Drugs, Athletes, and Physical Performance. Springer Science & Business Media. pp. 29–. ISBN 978-1-4684-5499-4.
  3. ^ a b c William Llewellyn (2011). Anabolics. Molecular Nutrition Llc. pp. 464–. ISBN 978-0-9828280-1-4.
  4. ^ Bergink EW, Janssen PS, Turpijn EW, van der Vies J (June 1985). "Comparison of the receptor binding properties of nandrolone and testosterone under in vitro and in vivo conditions". J. Steroid Biochem. 22 (6): 831–6. doi:10.1016/0022-4731(85)90293-6. PMID 4021486.