FDA Approved Drugs for Hair Loss Finasteride (Propecia®)—an oral medication that treats the root cause of male-pattern hair loss by inhibiting the activity of the hormone responsible for hair loss.Finasteride is available only by prescription. Finasteride is usually not prescribed for women; women who may become pregnant are at risk for a certain type of birth defect in the unborn child. Finasteride works best for early to moderate degrees of hair loss. Men with extensive hair loss are unlikely to have much regrowth. Regrowth associated with finasteride is better over the crown of the scalp than at the frontal receding hairline. When used in conjunction with hair transplantation, finasteride may prevent further hair loss while transplantation fills in areas such as the frontal hairline.