Dihydrotestosterone by Ray Sahelian, M.D.

DHT ( dihydrotestosterone ) is an androgen from testosterone through the action of the enzyme 5-alpha-reductase. 5-alpha-reductace concentrations are highest in the peripheral tissues (genital skin and hair follicles). Dihydrotestosterone is primarily responsible for the physical changes that occur during male sexual maturation and is thought to be related to sex drive as well as erectile capabilities in men. In addition, dihydrotestosterone has been associated with benign prostate hypertrophy (BPH) and prostate cancer.

Dihydrotestosterone and hair loss
Male and female pattern hair loss is thought to be due to the effects of dihydrotestosterone on genetically predisposed hair follicles. Binding of dihydrotestosterone to the hair follicle results in gradual miniaturization of the hair and eventual hair loss. Finasteride is a 5alpha-reductase inhibitor approved for the treatment of male pattern hair loss. Originally approved for the treatment of benign prostatic hypertrophy in 1992, its approval was expanded in 1997 to include the treatment of androgenetic alopecia in men at a dose of 1 mg/day. Finasteride inhibits 5alpha-reductase, thereby prohibiting the conversion of testosterone to dihydrotestosterone, which is implicated in the development of hairless in some men. Reduction in dihydrotestosterone results in a significant improvement in subjective and objective assessments of hair growth and density.

Natural Dihydrotestosterone blockers
There are certain herbs that may be natural dihydrotestosterone blockers, but, at this time, no long term studies have been done to determine if taking certain herbs has an influence on hair growth. Saw palmetto may be a partial dihydrotestosterone blocker in prostate tissue.

Dihydrotestosterone versus testosterone - how are they different?
Testosterone influences overt masculinization in the adult male, and dihydrotestosterone influences prostatic growth, acne, facial beard, and male pattern baldness. Inhibition of dihydrotestosterone in adults results in prostatic shrinkage and symptomatic relief in many men, without the serious side effects seen with conventional androgen-deprivation therapy.

Dihydrotestosterone questions
Q. I take finasteride to block testosterone to dihydrotestosterone. I have noticed my libido has dropped a little. Is this due to the dihydrotestosterone blocker use?
   A. Most likely. Blocking the conversion of testosterone to dihydrotestosterone does appear to negatively influence libido in some men.