Spironolactone is a prescription medication that is FDA-approved for the treatment of androgenic alopecia in women. It was originally developed as a blood pressure medication (diuretic) however it has anti-androgen properties. Androgens are hormones that play a role in hair loss. While spironolactone does have anti-androgen properties, it is less effective at inhibiting DHT than 5-alpha-reductase inhibitors like finasteride or spironolactone. Spironolactone is available in tablet form and should be taken once daily. The most common side effects of spironolactone include irregular periods, weight gain, and headaches.