Finasteride is a powerful 5-alpha reductase inhibitor found in this formulation. In normal testosterone metabolism, the body uses the enzyme 5-alpha reductase to convert it into dihydrotestosterone (DHT). Long-term exposure to DHT has been shown to shrink and damage hair follicles. Since 5-Alpha reductase is found in the oil glands of hair follicles, it is believed that this pathway is a potential culprit in the progression of androgenetic alopecia. Researchers have found that by suppressing the production of DHT, hair follicle miniaturization can be slowed down or stopped if caught early enough..