Spironolactone was approved by the US Food and Drug Administration (FDA) 30 years ago for several noncutaneous conditions, such as congestive heart failure. It acts as an aldosterone antagonist and thereby promotes diuresis, reduces blood pressure, and retains potassium.1 Aside from these mechanisms of action, spironolactone also exerts several antiandrogenic effects in the skin. Spironolactone decreases sebum production by competing with both dihydrotestosterone (DHT) and testosterone for the androgen receptors and also halts the conversion of testosterone to the more potent sebum producer DHT. In addition, spironolactone decreases type 2 17β-hydroxysteroid dehydrogenase and thereby inhibits androgen synthesis.2 These antiandrogenic actions make spironolactone well suited to treat androgen-driven cutaneous disorders, such as acne.