A method for inhibiting hair growth in mammals using compositions containing FP receptor antagonists (e.g., prostaglandin F analogs that are block activation of the FP receptor). The compositions can be applied topically to the skin and/or hair. The compositions can arrest hirsutism or hypertrichosis, reverse hirsutism and hypertrichosis, and further prevent hair growth. These compositions can also be used to protect hair from chemical or radiation-induced alopecia or hair loss. These compositions can also be used to inhibit pigmentation of the hair or skin.