5α-Dihydronandrolone

5α-Dihydronandrolone
Clinical data
Synonyms Dihydronandrolone; DHN; 5α-DHN; 5α-Dihydro-19-nortestosterone; 5α-Estran-17β-ol-3-one; 19-nor-5α-androstan-17β-ol-3-one
Identifiers
CAS Number
PubChem CID
ChemSpider
UNII
ChEMBL
Chemical and physical data
Formula C18H28O2
Molar mass 276.42 g/mol
3D model (JSmol)

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]

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
CompoundrAR (%)hAR (%)
Testosterone3838
5α-Dihydrotestosterone77100
Nandrolone7592
5α-Dihydronandrolone3550
EthylestrenolND2
NorethandroloneND22
5α-DihydronorethandroloneND14
Metribolone100110
Abbreviations: rAR = Rat prostate androgen receptor at 4°C. hAR = Intact human MCF-7 breast cancer androgen receptor at 37°C. Miscellaneous: Direct link to table. Sources: [4][5]

See also

References

  1. 1 2 3 4 5 6 7 8 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. 1 2 3 4 5 John A. Thomas (6 December 2012). Drugs, Athletes, and Physical Performance. Springer Science & Business Media. pp. 29–. ISBN 978-1-4684-5499-4.
  3. 1 2 3 William Llewellyn (2011). Anabolics. Molecular Nutrition Llc. pp. 464–. ISBN 978-0-9828280-1-4.
  4. 1 2 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.
  5. ↑ Bergink EW, Geelen JA, Turpijn EW (1985). "Metabolism and receptor binding of nandrolone and testosterone under in vitro and in vivo conditions". Acta Endocrinol Suppl (Copenh). 271: 31–7. doi:10.1530/acta.0.109S0031. PMID 3865479.


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