Birth control pills (oral contraceptives) are a method of birth control that uses hormones to prevent pregnancy. The man-made female hormones in the pills change a woman's natural hormone levels and prevent her ovaries from releasing an egg each month. The hormones also help prevent pregnancy in 2 other ways. They cause a thickening of the mucus on the cervix and they change the lining of the uterus. The thickened mucus on the cervix makes it hard for sperm to enter the uterus. The change in the lining of the uterus helps prevent a fertilized egg from attaching to the uterus.
The most commonly used pills are "combined" pills. They contain man-made forms of 2 hormones: estrogen and progesterone. There is also a progesterone-only pill (the mini-pill), but it is not as effective and causes a lot of blood spotting between menstrual periods.
The combined pills usually come in a package of 28 pills. They are also available in 21-pill or 91-pill packs. You and your healthcare provider will decide which type of package is best for you. Your provider will probably advise you to start taking the pills on the Sunday after your period has started or on the first day of your next period, depending on your preference.
21-day pill pack
If you are using the 21-pill pack, take 1 pill every day for 3 weeks. Stop taking the pills for 7 days and then start a new pack. Your period comes during the week that you are not taking pills.
28-day pill pack
If you are using the 28-day package, take 1 pill every day for 4 weeks and then start a new package the next day. The last 7 pills are inactive and contain no medicine for birth control. They just keep you in the habit of taking a pill every day. Your period comes during the week that you are taking the last 7 pills.
91-day pill pack
If you are using the 91-day pill pack, you take 1 pill of active medicine every day for 12 weeks (84 days). Then you take 1 inactive pill every day for 1 week (7 days). You will have your period while you are taking the inactive pills. This means that you have a period just once every 3 months.
Generally, most women have no trouble getting pregnant after they stop taking the pills. When you want to get pregnant, it is recommended that you wait until you have had at least 2 normal menstrual periods after stopping the pills. Getting pregnant while taking birth control pills or right after stopping them does not appear to cause problems with the baby.
Your risk of pregnancy increases when you miss any pills.
If you forget 1 pill, take it as soon as you remember, even if it is the next day. Take the next pill on time.
If you miss 2 or more doses in a row, see the information sheet that comes in the medicine package or ask your healthcare provider what to do. Use an additional method of birth control, such as condoms or spermicide, until your next period starts.
If you are breast-feeding your baby, do not use birth control pills unless your healthcare provider says it is OK. Remember that breast-feeding is not sure protection against pregnancy, so use another form of birth control before you start taking birth control pills again. Progesterone is usually the only hormone you can use when you are breastfeeding.
If you are not breast-feeding your baby, you may be able to start taking birth control pills 1 to 2 weeks after the birth or when you begin menstruating again. Use condoms or spermicides until you start the pills. Be sure to check with your healthcare provider before you start taking birth control pills again.
The benefits are:
One disadvantage of birth control pills is that you must remember to take a pill every day.
The pills usually have no side effects, but sometimes they cause side effects such as:
You should not smoke. Smoking increases the risk of serious side effects, such as heart attack, stroke, and blood clots. This is especially true if you are over 35 years old and smoke 15 or more cigarettes a day.
Other risks of taking birth control pills include cataracts, gallstones, and non-cancerous liver tumors.
Birth control pills do not protect you from sexually transmitted diseases such as AIDS. Latex or polyurethane condoms are the only safe way to protect against AIDS.
Some medicines can affect the way birth control pills work in your body. Birth control pills may not keep protecting you against pregnancy if you are taking certain antibiotics or medicines for seizures or fungal infections. Tell your healthcare provider about all medicines or natural remedies you are taking. You may need to use an additional form of birth control while you are taking these medicines.
Some women with chronic diseases or other problems should not use birth control pills. For example, women who have had blood clots, abnormal menstrual bleeding, high blood pressure, certain cancers, heart attack. or stroke should not use the pills. You should also not take birth control pills if you think you may be pregnant. Your healthcare provider will discuss your medical history with you.
Call your provider right away if you have:
Call during office hours if you have: