Hormone blockers (such as spironolactone, cyproterone acetate, and flutamide) are oral drugs that specifically reduce the production of testosterone by the adrenal glands and can thereby prevent DHT from having an effect on the hair follicle. But these are serious drugs and are not a consideration for men due to their feminizing effects, but can be considered an option for women, especially when combined with minoxidil. Studies indicate a good success rate especially when combined with the topical use of minoxidil. (Sources: British Journal of Dermatology, March 2005, pages 466-473; and The Journal of Clinical Endocrinology & Metabolism, January 2000, pages 89-94.)