Exemestane is a medication used to treat breast cancer.
Some breast cancers require estrogen to grow. Those cancers have estrogen receptors (ERs), and are called ER positive. They may also be called estrogen responsive, hormonally responsive, or hormone receptor positive. Aromatase is an enzyme that synthesizes estrogen. Aromatase inhibitors block the synthesis of estrogen. This lowers the estrogen level, and slows the growth of cancers.
Exemestane has been used in doping to raise luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels, which in turn increases the ratio of male over female sexual hormones and so improves performance. The drug also counteracts gynecomastia as well as fat and water retention following excessive aromatase production due to testosterone doping.