They are the most widely used and successful method of reversible birth control.
Oral contraceptives work by preventing the ovaries from ovulating, or releasing eggs.
Most BCP's use a combination of estrogen and progesterone. The BCP is taken for 21 to 25 days, followed by the use of placebo pills until day 28. The brain no longer signals the ovaries to produce and release an egg. Prior to beginning the pill, a woman will have a physical exam . This exam includes a pelvic examination, a PAP smear screening, blood pressure measurement and blood tests to check blood glucose and cholesterol levels.