The use of minoxidil in the treatment of male and female androgenetic alopecia: a story of more than 30 years.

Even if minoxidil has been known for over 30 years as "hair growth stimulator" the precise mechanism of its action is not completely elucitated. Minoxidil shortens telogen, accelerates telogen-exogen phase and causes the premature entry of resting hair follicles into anagen phase. Moreover, minoxidil increases hair follicle size. A large part of hair treatment scientific literature confirms the efficacy of topically applied minoxidil in humans. In particular, patients treated with minoxidil showed a significant increase in "non vellus" hair count starting from baseline. Preparation of minoxidil requires molecule stability and solubility. Today are available on the market minoxidil-based formulations having low-concentration of propylene glycol to obtain preparations with a better cosmetical acceptance and dermatological safety. The body of evidences indicates that minoxidil still represent a milestone in the treatment of androgenetic alopecia and that its story is going on.