Compare to the active ingredient in Rogaine for women. Hair Regrowth Treatment For Women, Minoxidil 5%, Topical Aerosol (Foam) contains the #1 Dermatologist Recommended Active Ingredient for hair regrowth (of U.S. Physicians surveyed by an independent market research firm). When used as directed, this once a day minoxidil foam works beneath the surface to reactivate hair follicles to stimulate hair regrowth on top of the scalp. For women who have a general thinning of hair on the top of the scalp.