Minoxidil is available over-the-counter and applied topically to the scalp skin in areas of hair loss. Monoxidil is marketed under the brand name Rogaine®. Minoxidil is available in both 2% and 5% strengths. The 5% strength has been shown to be more effective in both men and women in slowing hair loss and promoting new hair growth. Results of Minoxidil's effectiveness in slowing or halting hair loss to some degree in men have ranged from 50% to 80% of men treated. A lower percentage has reported new hair growth. Minoxidil is ineffective for some men and women who continue to lose hair.
While it is available without prescription it is used most effectively in a physician-guided program of hair restoration, after the cause of hair loss has been diagnosed. Minoxidil's mode of action is not completely understood. It appears to act to prolong the anagen (growth) phase of the hair follicle.