Male pattern hair loss, or androgenetic alopecia. Can be blamed on a hormone by-product called dihydrotestosterone (DHT).
DHT is an androgen and helps give males their male characteristics. It causes hair follicles to atrophy. This contributes to male pattern hair loss.
DHT can be treated with hair loss treatments
In men, the enzyme 5-alpha-reductase (5-AR) converts testosterone into DHT. In the testes and the prostate. Up to 10 per cent of testosterone is normally converted into DHT.
For reasons that are not well understood. DHT is essential for most hair growth. But it is detrimental to head hair growth. Male pattern hair growth is not affected by DHT. Around the back and sides of the head. With even advanced hair loss stages a man keeps a band of hair around the back and sides.
Male pattern hair loss can have a negative effect on the self-esteem of a man. To help relieve this, some treatments have already been developed. Finasteride was approved for safety and efficacy in 1997, by the U.S. Food and Drug Administration (FDA).
It is a selective inhibitor of type 2 5-AR. It is thought to act on the 5-AR enzyme that concentrates in the hair follicles to inhibit production of DHT. Finasteride can be taken orally, at a dose of 1 milligram (mg) every day. If treatment stops, hair loss will continue.
Adverse effects include a loss of libido, a reduced ability to develop and maintain an erection, and a decrease in ejaculate.