Hormones are substances produced naturally in the body. They act as chemical messengers and help control the activity of cells and organs. Hormonal therapies interfere with the way hormones are made or how they work in the body.
Many cancers need hormones to grow. Megestrol is a drug that is similar to the female sex hormone progesterone. It works by interfering with the hormone balance in the body, which may stop the cancer growing. It can also act directly on cancer cells so that they cannot grow.