Abstract
Androgenetic alopecia produces a chronic, progressive, patterned hair loss in both men and women. Androgen hormones and, in particular, dihydrotestosterone bind to androgen receptors in sensitized hair follicles. Susceptibility to androgenetic alopecia and, in particular, early-onset androgenetic alopecia is a complex polygenic trait. Polymorphism of the androgen receptor gene has been strongly associated with androgenetic alopecia in males but not in females. Drugs that inhibit androgen synthesis, androgen metabolism or the androgen receptor can be used to treat androgenetic alopecia. The principle roles of these medications are to arrest hair loss and to stimulate hair regrowth. While these agents are highly effective at preventing hair loss and most patients experience some regrowth, few patients experience dramatic hair regrowth. Minoxidil lotion has been shown to be effective in treating androgenetic alopecia. Its effects are nonandrogen-mediated and this agent can be combined with antiandrogen therapy for an additive effect, as can hair transplantation surgery.