This is a side effect, and 80% is kind of scary! You basically become a wolf-man.
Dermatologic-Hypertrichosis-Elongation, thickening, and enhanced pigmentation of fine body hair are seen in about 80% of patients taking minoxidil (minoxidil (minoxidil (minoxidil tablets) tablets) tablets) tablets. This develops within 3 to 6 weeks after starting therapy. It is usually first noticed on the temples, between the eyebrows, between the hairline and the eyebrows, or in the side-burn area of the upper lateral cheek, later extending to the back, arms, legs, and scalp. Upon discontinuation of minoxidil (minoxidil (minoxidil (minoxidil tablets) tablets) tablets) , new hair growth stops, but 1 to 6 months may be required for restoration to pretreatment appearance. No endocrine abnormalities have been found to explain the abnormal hair growth; thus, it is hypertrichosis without virilism. Hair growth is especially disturbing to children and women and such patients should be thoroughly informed about this effect before therapy with minoxidil (minoxidil (minoxidil (minoxidil tablets) tablets) tablets) is begun. Allergic-Rashes have been reported, including rare reports of bullous eruptions, and Stevens-Johnson Syndrome.