Antiprogestogen

An antiprogestogen, also called an antiprogesterone agent, or in the case of a synthetic compound, an antiprogestin, is a type of hormone antagonist which antagonizes or suppresses the action of progesterone in the body, a sex hormone that plays a role in the menstrual cycle and pregnancy. Antiprogestogens may stop some cancer cells from growing and they are being studied in the treatment of breast cancer. They are also used as abortifacients.