Compare to the active ingredient in Women's Rogaine. Hair Regrowth Treatment For Women, Minoxidil Topical Aerosol, 5% (Foam) contains Minoxidil 5%, the #1 Dermatologist Recommended Active Ingredient for hair regrowth. When used as directed, this once a day 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.