PROGESTIN
Progestin-only oral contraceptives are used to prevent pregnancy. Progestin is a female hormone. It works by preventing the release of eggs from the ovaries (ovulation) and changing the cervical mucus and the lining of the uterus. Progestin-only oral contraceptives are a very effective method of birth control, but they do not prevent the spread of AIDS and other sexually transmitted diseases.
Source: National Library of Medicine, Medline Plus 2008
