Minoxidil is a topical medication approved for both men and women. It currently is available as a 2% liquid, 5% liquid, and 5% foam. It thought to act as a direct anagen-prolonging agent. It is effective in both men and women, although not to the same degree as finasteride. Although the packaging inserts state it is for the vertex, it works in both the front and crown.
Personal experience, and experience from colleagues suggests that approximately 50% of men have their hair loss slowed or stopped, 20% show some signs of regrowth, and 30% continue to lose hair (i.e. no effect) .
A big problem with the use of minoxidil is compliance. In addition to irritation, the original product was oily and messy. The newer 5% foam contains no propylene glycol. It is much easier to use and is better accepted by patients. It was recently FDA approved for women as a once a day therapy.