Male-pattern baldness, another term for androgenetic alopecia, is due to the harmful effects of the male hormone called dihydrotestosterone or DHT. The result would be that there is significant hair loss in the front, top and crown of the scalp (rather than the sides and at the back of the head). Dihydrotestosterone causes one to lose hair by means of shortening the anagen phase (growth phase) of the hair growth cycle. This results to the decreased size or miniaturization of the hair follicles. The affected hair shafts become shorter and extremely finer, until it gradually breaks off and the root hairs cease growing.
DHT is created by the action of the enzyme known as 5-alpha reductase on the male hormone testosterone. The one that can block this kind of enzyme is called finasteride. By blocking the enzyme, the testosterone cannot be converted to dihydrotestosterone (DHT) in the hair follicles. Finasteride bears the brand name Propecia – the only oral medication for hair loss that is approved by the FDA. Continue reading