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Interested in alternatives to birth control pills? Visit UPMC's page on birth control shots to learn more.

Birth Control Pills — Combined Oral Contraceptives

What is “the Pill?”

The birth control pill, also known as “the pill,” is a medicine that can prevent pregnancy, make periods lighter and less crampy, and make periods come regularly. A birth control pill has two hormones: estrogen (ESS-tre-jen) and progestin (pro-JESS-tin). Taking the pill every day prevents your ovaries from releasing an egg every month. Progestin only contraceptives are another type of birth controll pill.

How Effective is the Pill in Preventing Pregnancy?

With typical use, about 8 women out of 100 who take the pill may become pregnant in 1 year. This means it is about 92 percent effective in preventing pregnancy. If you take the pill exactly as directed (correct and consistent use), less than 1 out of 100 may become pregnant in 1 year.

How Do I Start the Pill?

Your doctor or nurse will suggest 1 of the following methods to begin taking the pill:

  • Start your first pack of pills on the first day of your menstrual period. Use a backup method of birth control (such as condoms with spermicide) until you start the pill. The pill will start working right away for birth control if you start on the first day of your period.
  • Start your first pack of pills on the Sunday after you start your menstrual period. You should use a backup method of birth control (condoms with spermicide) until you start the pill. You also will need to use a backup method of birth control (condoms with spermicide) during the first 7 days of the pill package.
  • Start your pills today. If you start your pills today, you should use a backup method of birth control (condoms with spermicide) during the first 7 days of the pill package. Birth control pills will start to protect you from pregnancy after the first week, if you take them correctly.

How Do I Take the Pill Correctly?

Take 1 pill at the same time each day until you finish all of the pills in the pack. When you finish the last pill, start a new package of pills the next day.

  • Take the pills in the correct order.
  • Take the pills at the same time each day.
  • If you have nausea with your pill, try taking the pill with food, after eating, or at bedtime.
  • Your menstrual period will usually come during the last 7 days of each pill pack, once your body adjusts to the pills.
  • Start a new pill pack the day after you finish the last pill in your old pack.
  • Never miss a day of taking your pill.

What Should I Do if I Miss a Pill?

Be careful not to miss any pills, but if you do:

  • Take the pill as soon as you remember it.
  • Take your next pill at the correct time.
  • If you realize when taking your pill that you skipped one, take the pill you skipped and the new one together. It’s OK to take 2 pills at once.
  • If you forget to take a pill for 2 days in a row, take 2 pills each day for the next 2 days, and then go back to 1 pill each day. Use a backup method (condoms) for one week.
  • If you forget 3 or more pills in a row, start a new package of pills. Use a backup method (such as condoms with spermicide) for one week.
  • If you have sex when you have not been taking your pill correctly, or if the backup method fails (for example, the condom breaks), you should use emergency contraception to prevent pregnancy. If you do not already have emergency contraception at home, you can visit a drug store to buy ECP (emergency contraception, sometimes called the morning-after pill).
  • One brand of ECP (such as Plan B One-Step® or Next Choice)®, is often kept behind the pharmacy counter so you have to ask for it, but you do not need a prescription unless you are under age 17. Another brand of ECP, called ella®, requires a prescription for women of all ages.
  • If you have severe nausea and vomiting and can't keep the birth control pill in your stomach, you can put the pill in your vagina. You will get the same effect from the hormone in the pill in your vagina as compared to swallowing the pill.

What Side Effects Will I Have?

Minor side effects usually will go away within 3 months after starting birth control pills.
These may include:

  • Nausea
  • Headache
  • Breast tenderness
  • Bloating, water weight gain
  • Mood changes
  • Depression
  • Bleeding/spotting between periods (called break-through bleeding) — call your doctor or nurse if you soak 1 or more pads or tampons each hour.
  • Missed periods — If you skip 1 period and have taken your pills correctly, start a new pill pack as you normally would. Take a pregnancy test 1 week into your new pill pack if you do not start to bleed. If the test is negative, continue taking the pills. If the test is positive, stop the pills and call your doctor. If you miss more than 2 periods in a row, call your doctor.

Do not stop taking your pills if these side effects happen. They often go away within 3 months as your body fully adjusts to the pills. If the side effects bother you a lot, make an appointment to see your doctor.

Serious side effects are very rare, but they may occur. Call your doctor right away if you have:

  • Severe headaches that do not go away
  • Loss of vision or change in vision
  • Numbness in any body part
  • Severe chest pain
  • Difficulty breathing
  • Coughing up blood
  • Fainting
  • Severe leg pain (calf or thigh)

Smoking can increase the risk of complications associated with the pill.

Birth control pills that contain estrogen can increase your risk of a blood clot that can travel to the lungs or brain, but the risk is still less than the risk of blood clots during pregnancy.

Don’t Run Out of Pills

Call to schedule a return appointment with your doctor when you have 2 packs of pills left on your prescription. Plan ahead so you don’t run out of pills.

Will Other Medicines Affect the Way Birth Control Pills Work?

Some drugs can prevent the birth control pill from working well. Talk with our doctor if you take any of these drugs.

These include:

  • Drugs to prevent seizures (anticonvulsant drugs): phenobarbital, carbamazepine (Tegretol®), primidone, ethosuximide, and phenytoin (Dilantin®), barbiturates, topiramate, and oxcarbazepine
  • Antibiotics: Rifampin (rifampicin), griseofulvin. If you are taking antibiotics, it is recommended that you use a back-up method (such as condoms with spermicide). Continue to take your  pills and use a backup method of birth control (condoms with spermicide) during the time you take the antibiotics. Continue to use the backup method for 48 hours after the prescription is finished.
  • Anti-HIV medications
  • St. John’s Wort: Some recent studies suggest that St. John’sWort may affect birth control pills, so that they don’t work. If you think you must use St. John’sWort, talk with your doctor.

What if I Just Had a Baby?

Combined oral contraceptives are not recommended the first 21 days after the birth of a baby due to the increase risk of a blood clot in the legs. They are also not recommended for breastfeeding mothers until 4 weeks after delivery because they can have an affect on the milk supply.


If you have any questions or need more information, call your doctor.

Use condoms the right way

To protect against STDs (sexually transmitted diseases), use condoms the right way.

Except for not having sex (abstinence), latex condoms give the best protection from many STDs including HIV, the virus that causes AIDS. Condoms are helpful only if used the right way. Use a latex condom every time you have sex. Always put the condom on before the penis touches or enters the vagina. If you or your partner has an allergy to latex, you should use a plastic (polyurethane) condom.

Important steps for using condoms the right way:

  1. Check the expiration date.
  2. Check the condition of the package.
  3. Open the package carefully.
  4. Hold the condom by the last 1/2 inch at the tip, and squeeze out the air.
  5. If the penis is uncircumcised, pull back the foreskin.
  6. Place the condom on the tip of the penis.
  7. Unroll the condom to the base of the penis. Smooth out any extra air.
  8. If you want or need to use lubricant on the condom, only use water-based lubricants like K-Y Jelly or Surgilube. Do not use oil-based lubricants. They can weaken condoms and cause them to break. Do not use petroleum jelly, cooking or vegetable oil, mineral or baby oil, massage oil, butter, margarine, oil-based creams, or lotions.
  9. Immediately after ejaculation, hold the condom firmly by the rim at the base of the penis, and pull the penis and condom out of the vagina together, while the penis is still erect.
  10. Look carefully at the condom to see if there is a hole in it. If you are not sure, fill the condom with water to see if it leaks.
  11. Discard the condom. Wrap it in tissue, and throw it away. Do not flush it down the toilet.
  12. Never re-use a condom.



For UPMC Mercy patients: UPMC Mercy, a Catholic hospital, abides by the Ethical and Religious Directives for Catholic Health Care Services, as determined by the United States Conference of Catholic Bishops. As such, UPMC Mercy neither endorses nor provides medical practices or procedures that contradict the moral teachings of the Roman Catholic Church.


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For UPMC Mercy Patients: As a Catholic hospital, UPMC Mercy abides by the Ethical and Religious Directives for Catholic Health Care Services, as determined by the United States Conference of Catholic Bishops. As such, UPMC Mercy neither endorses nor provides medical practices and/or procedures that contradict the moral teachings of the Roman Catholic Church.

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