Nioxin Hair Regrowth Treatment Minoxidil topical solution 2% is for women who have a general thinning of hair on the top of the scalp as shown. Minoxidil topical solution 2% has been shown to regrow hair in women with the following degrees of thinning hair or hair loss. Active ingredient Purpose Minoxidil 2% w/v Hair regrowth treatment use to regrow hair on the scalp. | Nioxin Minoxidil Hair Regrowth Treatment For Women, 2 fl. oz | Dermstore