The treatment of male pattern baldness (MPB) was revolutionized in 1998 by the release of Propecia (finasteride 1 mg) by Merck. The drug works by blocking the formation of dihydrotestosterone (DHT) in the scalp; DHT is the form of testosterone that causes hair loss in the vast majority of men and women by binding to follicles and gradually rendering them unable to continue growing hair. Now available in generic 1 mg and 5 mg tablets (the latter can be quartered with a dramatic reduction in monthly cost), finasteride remains the gold standard for treating male hair loss (and occasionally post-menopausal female hair loss). A large, carefully performed study found that after five years, the drug was effective for 90% of men (42% maintained hair, while 48% actually gained some hair). During the same period, 75% of those not taking finasteride continued to lose hair. No drug is completely without side effects, but the documented side effects of finasteride are rare. The combined incidence of decreased libido and erectile dysfunction is 1.1% when the documented placebo effect is subtracted. Because of the potential detrimental effects on pregnant women, people on Propecia (finasteride) cannot donate blood.
Though this drug has not been approved by the FDA for treatment of male pattern hair loss (androgenetic alopecia), it is often used off-label with results that can rival or surpass those with Propecia (finasteride). Whereas Propecia (finasteride) is an inhibitor of the Type II 5-alpha reductase enzyme responsible for the conversion of testosterone to dihydrotestosterone (DHT), Avodart (dutasteride) blocks both the Type I enzyme and the Type II enzyme. Along with its increased effectiveness as a DHT blocker comes a higher incidence and longer duration of side effects with Avodart (dutasteride). As with Propecia (finasteride), people taking Avodart (dutasteride) may not donate blood.
Originally developed in pill form to treat high blood pressure, minoxidil was found to cause hypertrichosis (excessive hair growth over the body). It was released as a topical solution, Rogaine, for application to the scalp in 1988. Generic minoxidil became available in 1996. A more convenient foam preparation (minus the propylene glycol which can cause scalp irritation) now seems to be preferred by most people. The drug is not as effective as finasteride, but it can be beneficial for both men and women with “miniaturized” (thinning) hair. Though claimed to be helpful only for the crown (back of the head), anyone who treats hair loss on a regular basis knows that benefits can be seen in any thinning area of the scalp. For men, the combination of finasteride and minoxidil can be particularly effective. Women may use the men’s formula (5%) once a day, instead of the women’s formula (2%) twice a day.
NOTE: All three of the above drugs can enhance growth following a hair transplant.