Combination birth control pills

Combination birth control pills, also known as the pill, are oral contraceptives that contain estrogen and a progestin.

Combination birth control pills suppress ovulation — keeping your ovaries from releasing an egg. Combination birth control pills 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. Some combination birth control pills, called continuous or extended-cycle pills, allow you to reduce the number of periods you have each year. If you'd like to use combination birth control pills, your health care provider can help you decide which type is right for you.


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Combination birth control pills are a reliable form of contraception that is also easily reversed. Fertility may return to normal almost immediately after stopping combination birth control pills. Combination birth control pills have noncontraceptive benefits as well, such as:

  • Decreased risk of ovarian and endometrial cancers, ectopic pregnancy, ovarian cysts, benign breast disease
  • Improvement in acne
  • Less severe menstrual cramps (dysmenorrhea)
  • Reduction in androgen production caused by polycystic ovary syndrome
  • Reduction in heavy menstrual bleeding due to uterine fibroids and other causes, as well as a reduction in related iron deficiency anemia
  • Relief from premenstrual syndrome (PMS)
  • Shorter, lighter and more predictable periods or, for some types of combination pills, fewer periods each year
  • Better control of monthly cycle and a reduction in hot flashes for women in perimenopause

Combination birth control pills come in different mixtures of active and inactive pills, including:

  • Conventional pack. The most common type of combination birth control pills contains 21 active pills and seven inactive pills. Formulations containing 24 active pills and four inactive pills, known as a shortened pill-free interval, also are available. A pill is taken every day and a new pack is started when the previous pack is completed (every 28 days). Bleeding occurs every month during the week when you take the last four to seven inactive pills.
  • Continuous dosing or extended cycle. These combination birth control pills typically contain 84 active pills and seven inactive pills. Bleeding generally occurs only four times a year during the week when you take the inactive pills.

    A 365-day pill is also available. This pill is taken every day at the same time. For some women, periods stop altogether. For others, periods become significantly lighter.

Continuous dosing or extended cycle pills may provide additional benefits of suppressing menstruation, such as:

  • Prevention and treatment of excessive bleeding related to uterine fibroids
  • Prevention of menstrual migraine
  • Reduction in the menstruation-associated worsening of certain conditions, including seizures and asthma
  • Relief from pain related to endometriosis

Combination birth control pills aren't appropriate for everyone, however. Your health care provider may suggest another form of birth control instead of combination birth control pills if you:

  • Are in the first month of breast-feeding
  • Are older than age 35 and smoke
  • Have poorly controlled high blood pressure
  • Have a history of or current deep vein thrombosis or pulmonary embolism
  • Have a history of stroke or heart disease
  • Have a history of breast cancer
  • Have migraines with aura
  • Have diabetes-related complications, such as nephropathy, retinopathy or neuropathy
  • Have liver disease
  • Have unexplained uterine bleeding
  • Will be immobilized for a prolonged period due to major surgery
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