Dihydrotestosterone

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For other uses, see DHT (disambiguation).
Dihydrotestosterone
Systematic (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
Identifiers
CAS number 521-18-6
ATC code A14AA01
PubChem 10635
Chemical data
Formula C19H30O2 
Mol. mass 290.440 g/mol
Pharmacokinetic data
Bioavailability Oral 0-2%
Metabolism Hepatic
Half life  ?
Excretion Renal
Therapeutic considerations
Pregnancy cat.

X
Legal status

Schedule III (US), Schedule IV (CA)
Routes Intramuscular, transdermal

Dihydrotestosterone (DHT) (Full name: 5α-Dihydrotestosterone, abbreviating to 5α-DHT; INN: androstanolone) is a biologically active metabolite of the hormone testosterone, formed primarily in the prostate gland, testes, hair follicles, and adrenal glands by the enzyme 5α-reductase by means of reducing the 4,5 double-bond. Dihydrotestosterone belongs to the class of compounds called androgens, also commonly called androgenic hormones or testoids. Androgens are part of the biology of gender by stimulating and controlling the development and maintenance of masculine characteristics. DHT is 3 times more potent than testosterone; testosterone is 5-10 times more potent than adrenal androgens.[1]

While DHT is known mostly just for male pattern hair loss and prostate problems, it is crucial to virilization and is necessary to mitigate estrogen's effects in men.

Contents

[edit] Significance

Testosterone. Note the major difference -- the 4,5 double-bond on the A (leftmost) ring.
Testosterone. Note the major difference -- the 4,5 double-bond on the A (leftmost) ring.

DHT is produced by males in utero and is responsible for the formation of male sex-specific characteristics. DHT is an important contributor to other characteristics generally attributed to males, including facial and body hair growth, and deepening of the voice. DHT also plays a crucial role in both sex drive and the growth of muscle tissue.[2] Unlike other androgens such as testosterone, DHT cannot be converted by the enzyme aromatase to estradiol[3]. It therefor frequently used in research settings to distinguish between effects of testosterone caused by binding to the androgen receptor, and those caused by testosterone's conversion to estradiol and subsequent binding to estrogen receptors.

[edit] Pathology

DHT is the primary contributing factor in male-pattern baldness. This is not the case for women; female-pattern baldness is characterized by increased rates of production of testosterone, but not of DHT.[4] Women with increased levels of DHT may develop certain androgynous male secondary sex characteristics, including a deepened voice and facial hair. DHT also plays a role in the development or exacerbation of benign prostatic hyperplasia, or BPH, and prostate cancer, by enlarging the prostate gland.[5]

DHT is also known to participate in the development in some cases of acne.

[edit] Treatment

The drugs belonging to the group known as 5α-reductase inhibitors are used for treatment of problems stemming from DHT. This group includes finasteride (sold under the names Proscar for BPH and Propecia for androgenic alopecia as well as in generic formulation) and dutasteride (sold under the name Avodart). Dutasteride is three times more potent than finasteride inhibiting the type II enzyme and 100 times more potent than finasteride inhibiting the type I form of the DHT producing enzyme. Dutasteride is not approved by the FDA for the treatment of Male Pattern Hair Loss and is approved at a dose of 0.5 mg a day for the treatment of prostate enlargement. While both the type I and type II enzymes are found in the hair follicle, there is a recent study which shows that type I is present in the human brain. The function of this enzyme in the brain is still unclear.[6]

Currently, DHT supplementation is not used as a treatment for DHT/androgen deficiency.

[edit] References

  1. ^ [1]
  2. ^ Max Muscle Sports & Fitness
  3. ^ [2]
  4. ^ Production rates of testosterone and of dihydrotestosterone in female pattern hair loss
  5. ^ http://tuberose.com/Prostate.html
  6. ^ Update on Dutasteride | IAHRS Hair Transplant & Hair Loss Info Center
v • d • e
Anabolic steroids (A14) (trademark names in brackets)
Androstan (carbon 19 present)
Estren (carbon 19 absent)