Chemical Name: FINASTERIDE (fi-NAS-teer-ide) PROPECIA(Finasteride) is a medication prescribed to treat and preventmale pattern baldnessin male patients. Male pattern baldness (androgenetic alopecia) typically occurs in adults over the age of 18. In men with this condition, the scalp contains hair follicles with an increased amount of receptors for dihydrotestosterone (DHT) compared to those without male pattern baldness. DHT receptors often increase with age. PROPECIA works by lowering the amount of circulating DHT, preventing the destruction of hair follicles. PROPECIA is a 5-alpha-reductase inhibitor and works by preventing enzyme 5-alpha-reductase from converting testosterone to DHT. PROPECIA may take several weeks or months to begin showing a noticeable effect. PROPECIA must be taken every day to work effectively.