Regaine Foam contains the active ingredient Minoxidil 5 Percent Regaine foam for men works by preventing further hair loss and helping hair to regrow. It contains Minoxidil which is thought to work by helping the blood flow to the hair follicles on your scalp. Regaine foam can be applied to dry hair after swimming and can be used on dyed hair as long as the person who is applying the coloring massages it gently into your scalp to prevent breakage to the newly grown hair.