Androgenetic Alopecia, commonly known as male pattern baldness (MPB), accounts for more than 95% of hair loss in men. By age 35, two-thirds of American men will have some degree of appreciable hair loss and by age 50, approximately 85% of men have significantly thinning hair. About 25% of men who suffer from male pattern baldness begin the painful process before they reach 21.
Contrary to societal belief, most men who suffer from male pattern baldness are extremely unhappy with their situation and would do anything to change it. Hair loss affects every aspect of their life. It affects interpersonal relationships as well as their professional life. It is not uncommon for men to change their career paths because of hair loss.
A variety of genetic (and possibly environmental) factors apparently play a role in androgenic alopecia. Although researchers have long studied the factors that may contribute to this condition, many remain unknown. Minimally, pattern hair loss is related to hormones called androgens, particularly dihydrotestosterone (DHT). Androgens are important for normal male sexual development before birth and during puberty. Androgens also have other important functions in both males and females, such as regulating hair growth and sex drive.
Male pattern baldness is caused by a genetic sensitivity of hair follicles to DHT. This hormone causes follicles to shrink or “miniaturize.” In turn, this shortens their lifespan and prevents them from producing hair normally.
Recently, the existing theories have been challenged on the ground that while the androgens in question are responsible for hair growth on the face and all over the body of men, hair loss only occurs at the top of the scalp. Recent research suggests that elevated levels of the enzyme prostaglandin D2 synthase and its product prostaglandin D2 (PGD2) in hair follicles causes androgenetic alopecia.