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| Clinical data | |
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| Other names | Dihydronandrolone; DHN; 5α-DHN; 5α-Dihydro-19-nortestosterone; 5α-Estran-17β-ol-3-one; 19-nor-5α-androstan-17β-ol-3-one |
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| Chemical and physical data | |
| Formula | C18H28O2 |
| Molar mass | 276.420 g·mol−1 |
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5α-Dihydronandrolone (also known as5α-DHN,dihydronandrolone,DHN,5α-dihydro-19-nortestosterone, or5α-estran-17β-ol-3-one) is anaturally occurringanabolic–androgenic steroid (AAS) and a5α-reducedderivative ofnandrolone (19-nortestosterone).[1] It is a majormetabolite of nandrolone and is formed from it by the actions of theenzyme5α-reductase analogously to the formation ofdihydrotestosterone (DHT) fromtestosterone.[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 theskin,hair follicles, andprostate gland, among others.[1] The conversion of testosterone into DHT is an important factor in theetiology of a variety ofandrogen-dependent conditions, includingacne,excessive facial/body hair growth,scalp hair loss,prostate enlargement, andprostate cancer.[1] Unlike the case of testosterone and DHT, 5α-DHN is a much weakeragonist of theandrogen 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 ofanabolic toandrogenic effects seen with nandrolone.[1][2]
The combination of nandrolone with a5α-reductase inhibitor likefinasteride ordutasteride 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 androgenicside effects.[3]
| 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. | ||||||||
