Regaine contains Minoxidil, the only over-the-counter treatment clinically proven to help prevent further hereditary hair loss. Regaine products include Regaine Extra Strength, Regaine Regular Strength, Regaine Gel, Regaine For Women and Pregaine Shampoo. For some people, using Regaine even reverses the process, resulting in regrowth. Minoxidil, the active ingredient in Regaine, has been extensively researched and tested for its effectiveness in treating hereditary hair loss. Scientists believe it works by helping the blood flow to the hair follicle, stimulating and prolonging hair growth. It has been shown to help prevent further hair loss in 4 out of 5 men and help stimulate regrowth for a thicker, fuller head of hair.