Combination birth control pills, also known as the pill, are oral contraceptives that contain estrogen and a progestin.
Combination birth control pills keep your ovaries from releasing an egg. They also cause changes in the cervical mucus and the lining of the uterus (endometrium) to keep sperm from joining the egg.
Different types of combination birth control pills contain different doses of estrogen and progestin. Continuous-dosing or extended-cycle pills allow you to reduce the number of periods you have each year.
If you want to use combination birth control pills, your health care provider can help you decide which type is right for you.