Dihydrotestosterone

Dihydrotestosterone

Clinical data
Pregnancy category	X
Routes of administration	Intramuscular, transdermal
ATC code	A14AA01 (WHO)
Pharmacokinetic data
Bioavailability	Oral: 0–2%
Metabolism	Hepatic
Excretion	Renal
Identifiers
IUPAC name (5S,8R,9S,10S,13S,14S,17S)-17-hydroxy-10,13-dimethyl-1,2,4,5,6,7,8,9,11,12,14,15,16,17-tetradecahydrocyclopenta[a]phenanthren-3-one
CAS Number	521-18-6 Y
PubChem (CID)	10635
IUPHAR/BPS	2856
DrugBank	DB02901 Y
ChemSpider	10189 Y
UNII	08J2K08A3Y Y
ChEBI	CHEBI:16330 Y
ChEMBL	CHEMBL27769 N
ECHA InfoCard	100.007.554
Chemical and physical data
Formula	C19H30O2
Molar mass	290.442 g/mol
3D model (Jmol)	Interactive image
SMILES O=C4C[C@@H]3CC[C@@H]2[C@H](CC[C@]1(C)[C@@H](O)CC[C@H]12)[C@@]3(C)CC4
InChI InChI=1S/C19H30O2/c1-18-9-7-13(20)11-12(18)3-4-14-15-5-6-17(21)19(15,2)10-8-16(14)18/h12,14-17,21H,3-11H2,1-2H3/t12-,14-,15-,16-,17-,18-,19-/m0/s1 Y Key:NVKAWKQGWWIWPM-ABEVXSGRSA-N Y
NY (what is this?)

Dihydrotestosterone (DHT), or 5α-dihydrotestosterone (5α-DHT), also known as 5α-androstan-17β-ol-3-one, is an endogenous androgen sex steroid and hormone. The enzyme 5α-reductase catalyzes the formation of DHT from testosterone in certain tissues including the prostate gland, seminal vesicles, epididymides, skin, hair follicles, liver, and brain. This enzyme mediates reduction of the C4-5 double bond of testosterone. Relative to testosterone, DHT is considerably more potent as an agonist of the androgen receptor (AR).

DHT has an affinity (K_d) of 0.25 to 0.5 nM for the human AR, which is about 2- to 3-fold higher than that of testosterone (K_d = 0.4 to 1.0 nM) and 15–30 times higher than that of adrenal androgens. The dissociation rate of DHT from the AR is 5-fold slower than that of testosterone. The EC₅₀ of DHT for activation of the AR is 0.13 nM, which is about 5-fold higher than that of testosterone (EC₅₀ = 0.66 nM). In bioassays, DHT has been found to be 2.5- to 10-fold more potent than testosterone.