Minoxidil is an antihypertensive vasodilator medication which also slows or stops hair loss and promotes hair regrowth. Now off-patent, it is available over-the-counter for the treatment of androgenic alopecia. Minoxidil must be used indefinitely for continued support of existing hair follicles and the maintenance of any experienced hair regrowth.
Widely available in generic versions and under the brand name Rogaine, minoxidil seems to be more effective for women suffering from diffuse androgenetic alopecia than it is for men. Product labeling recommends that women only use the 2% concentration of minoxidil, not 5%, because the FDA has not approved use of the higher concentration in women.