Definition

A type of birth control that uses hormones to prevent pregnancy. Hormonal contraceptives contain estrogen and progesterone, or progesterone only. They prevent pregnancy by blocking the release of eggs from the ovaries, thinning the lining of the uterus, or thickening the mucus in the cervix to help keep sperm from reaching the egg. Hormonal contraceptives may be taken by mouth, injected or inserted under the skin, placed on the skin as a patch, or placed in the vagina or uterus.