Topically applied Minoxidil was the first medication approved by the FDA for male and female pattern hair loss. It is available over the counter in 2% and 5% strengths. The original studies on Rogaine were performed on the crown, so there is a misconception that it only works in this area. Although minoxidil usually works best in the crown, it also works to a lesser degree in other areas, such as the front of the scalp, as long as there is some fine (miniaturized) hair in the area. It does not work when the area is totally bald. The greatest benefit from the medication is seen from 5 months to 2 years, with a gradual decrease in effectiveness after that. Those using minoxidil long-term will continue to lose hair, but at a somewhat slower rate.
Oral finasteride is FDA approved for use in male pattern baldness. This drug is a 5 alpha reductase inhibitor that reduced the formation of dihydrotestosterone (DHT), a testosterone metabolite that has been shown to promote androgenetic alopecia (pattern hair loss). In some cases, finasteride may also be prescribed (off label) for women with evidence of female pattern hair loss. Although usually prescribed for post menopausal or women who are no longer of child bearing potential, finasteride may occasionally be prescribed to pre-menopausal women. In these instances pregnancy MUST be avoided while taking finasteride as well as for a period of time following finasteride therapy.
Dutasteride is similar in its mechanism of action to finasteride although because it is a stronger inhibitor of 5 alpha reductase it may have greater efficacy than finasteride in retaining and regrowing hair. However, the incidence of side effects, primarily sexual, are higher with use of this medication. The use of dutasteride for male and female patten hair loss is not FDA approved for this use and is considered “off-label.” Dutasteride will sometimes be discussed as a treatment option for patients who have continued to lose hair after an adequate trial of finasteride therapy.
Spironolactone is a medication that is primarily used to treat high blood pressure. However, because of its anti-androgenic effects this medication has been used off label in women who suffer from hormonal acne, hirsutism (body and facial hair growth) and female hair loss. Spironolactone inhibits the binding of androgens to their cellular receptors and decreases testosterone synthesis. Since the medication is a diuretic and is potassium sparing it is important to avoid supplemental or excessive potassium intake and to have periodic monitoring of potassium blood levels. Because of sexual side effects due to testosterone inhibition spironolactone is not an option for treatment of hair loss in men.
Latisse is FDA approved for treatment of eyelashes to promote thickening and growth. This medication is also used off label to promote thickening of eyebrows. A similar version of this drug is currently being studied for use in scalp hair loss.