Methods and compositions for stimulating the growth of hair are disclosed wherein said compositions include bimatoprost and minoxidil in a vehicle for topical application to the skin of a mammal, e.g. a human, whereby the combination of bimatoprost and minoxidil produces a faster onset of hair growth in humans or other mammals and wherein said composition brings about a synergistic result of faster onset of hair growth as compared to compositions comprising bimatoprost and minoxidil, alone.
