DHT: The Hair Killer
DHT (Dihydrotestosterone) is a normal male hormone, or Androgen, that is produced from Testosterone by a very interesting group of enzymes, 5-alpha reductase 1, 2, and 3.
The reason these enzymes are interesting is that certain families in the Dominican Republic, deficient in 5-alpha reductase, do not develop prostate enlargement and do not develop male pattern baldness! This observation, made in the late 60’s, ultimately revealed the specific Androgen responsible for prostate enlargement and hair loss, namely Dihydrotestosterone or DHT.
It’s important to note that Dihydrotestosterone is a normal male hormone or Androgen. This Androgen is especially important, allowing the male fetus to develop a normal urogenital tract; absence of DHT results in ambiguous genitalia in newborn males. In adults, DHT causes prostate enlargement and hair loss.
DHT Mediated Miniaturization
In men with androgenetic thinning, the normally present DHT causes the genetically predisposed follicles, within the thinning pattern, to shrink. This DHT mediated process is called miniaturization.
It follows that if we block 5-alpha reductase from producing DHT, we would also block the balding effects of this hair killing Androgen. An FDA approved medication developed by Merck, called Propecia (Propecia is 1 mg of Finasteride), inhibits the conversion of Testosterone (T) to Dihydrotestosterone (DHT) and is used to treat hair loss.
Early treatment with Finasteride can, in some patients with moderate thinning, reverse the miniaturization effects of DHT.
AVODART and Proscar
Another medication called Avodart, developed by GlaxoSmithKline, also inhibits the 5-alpha reductase enzymes, but in a more complete fashion than Finasteride. Avodart, or Dutasteride, is FDA approved for the treatment of prostate enlargement. Proscar (Proscar is 5 mg of Finasteride), is also FDA approved for the treatment of prostate enlargement.