Why it's done
By Mayo Clinic Staff
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 surger