What is birth control?

Birth control is a way to prevent pregnancy. There are many different birth control methods. Some also reduce the risk for sexually transmitted infections (STIs). In the United States, just under half of pregnancies are unintended (occur when the woman wasn't planning for it).

The birth control pill, often referred to as "the pill," is a form of birth control used by women that is taken by mouth. When taken correctly, it is 98% effective. However, because many women do not take it correctly, on average about 9% of women have an unintended pregnancy each year while on the pill. The pill does not protect against STIs, including HIV (the virus that causes AIDS). The male latex condom provides the best protection from most STDs.

How does the pill work?

Normally, a woman becomes pregnant when an egg released from her ovary (the organ that holds her eggs) is fertilized by a man's sperm. The fertilized egg attaches to the woman's womb (uterus), where it receives nourishment and develops into a fetus.

Hormones in a woman's body control the release of the egg from the ovary and prepare the body to accept a fertilized egg. The pill contains a small amount of synthetic (artificial) hormones. These hormones work with the body's natural hormones to prevent pregnancy. The pill prevents the body from releasing an egg from the ovary (which is called ovulation). It also thickens up the mucus at the cervix (the entrance to the uterus). This helps prevent sperm from reaching the ovary.

What does the pill contain?

Most pills contain a combination of two female hormones, estrogen and progestin. Different pills contain various strengths of these hormones. The "mini" pill only contains progestin.

Where can I get birth control pills?

Birth control pills are available with a doctor's prescription. In a few states, they are available over-the-counter, after you discuss your medical history with a trained pharmacist.

How are the pills packaged?

You will receive a set of pills packaged in a thin case. The FDA has approved birth control pills for extended cycles beyond the traditional one-month cycle. These are packages that contain continuous active pills for three months, or the entire year.

Taking birth control pills continuously improves their effectiveness. Also, women who have medical problems during their menstrual cycle (including acne, headaches, premenstrual syndrome [PMS]) usually have an improvement in symptoms if they are on a continuous regimen.

Other options have 21-26 active pills, with two to seven days of placebo (sugar pills) to complete a 28-day cycle. The placebo pills do not contain hormones; they are used when you expect to have a menstrual flow (period). They are added to remind you to start a new pill pack after 28 days.

Talk to your doctor about which options are best for you.

How do I take the first pill pack?

The first pill pack can be started any time a woman is sure that she is not pregnant. International medical guidelines advise that a woman can be reasonably certain that she is not pregnant if she has no symptoms or signs of pregnancy, and meets any one of the following criteria:

  • Is within seven days after the start of normal menses (period);
  • Has not had sexual intercourse since the start of last normal menses;
  • Has been correctly and consistently using a reliable method of contraception;
  • Is within seven days of a spontaneous or induced abortion;
  • Is within four weeks postpartum (delivery of a baby);
  • Is fully or nearly fully (at least 85% of the time) breast-feeding. In order to be confident that you are not pregnant while you are breast-feeding, you should not have any menstrual bleeding and also be within six months of delivery.

Birth control pills can be safely taken while you are breast-feeding. However, you should speak with your doctor about when is the best time to start the pill after delivering a baby.

It's best to take the pills at the same time every day. Some people find it helpful to set a timer or place a daily reminder in a calendar.

When do I start another pill pack?

You will start each new pill pack on the same day of the week. For example, if you start your first pill pack on a Sunday, you will start your next pill pack on a Sunday.

If you are on the 21-day pill pack (which does not contain placebo pills), start the new pill pack seven days after you finished the old pill pack. If you are on the 28-day pill pack, begin the new pack after taking the last pill in the old pack. Your doctor may recommend a different schedule of taking the pill if you will be using it continuously.

Start your new pill pack as scheduled above, whether or not you get your period or are still having your period.

How soon does the pill work?

Your body will need about one to three months to adjust to the pill. Use another form of birth control, such as latex condoms, during the first week. After the first week of taking pills regularly, you can use only the pill for birth control.

What if I forget to take a pill?

If you forget to take a pill, take it as soon as you remember. If you don't remember until the next day, go ahead and take two pills that day.

If you forget to take your pills for two days, take two pills the day you remember and two pills the next day. Continue taking the remaining pills at the usual time. Use backup protection (such as condoms), or avoid sexual intercourse until the pill has been taken for seven days.

Call your doctor for instructions on how to take the remainder of the pill pack. Your doctor may discuss emergency contraception with you if avoiding pregnancy is a high priority (such as in women with complicated medical problems or who are taking medications that may potentially be harmful for a baby).

When you forget to take a pill, you increase the chance of releasing an egg from your ovary. If you miss your period and forgot to take one or more pills, get a pregnancy test. If you have any questions about missing doses or if you have pregnancy concerns, call your doctor.

Are there side effects associated with the pill?

Yes, although the majority of the side effects are not serious. They include:

  • Nausea
  • Sore or swollen breasts
  • Small amount of blood, or spotting, between periods
  • Lighter periods
  • Mood changes (could be changes for the better or worse)

Most of these side effects improve with continued use of the pill over 2-3 months.

The following side effects are less common but more serious. If you have any of these, contact your doctor immediately. If you cannot reach your doctor, go to an emergency room or urgent care center for evaluation. These symptoms may indicate a serious disorder, such as gallbladder disease, blood clots, or high blood pressure. They include:

  • Abdominal pain (severe, in the upper right abdomen)
  • Chest pain, difficulty breathing
  • Swelling and/or aching in the legs and thighs

Studies show that with the lower doses of birth control pills commonly used today, chances of strokes or heart attacks are minimal. The vast majority of the pills used today contain 35 mcg or less of estrogen. However, there may be a risk of heart attacks or strokes in women who take higher dose estrogen pills (more than 30 mcg).

Can any woman take the pill?

The pill can be taken safely by most women, but is not recommended for women who are over the age of 35 if they smoke. Non-smokers can use the pill until menopause. You should not take the pill if you have had:

  • Blood clots
  • Serious heart disease
  • Unexplained vaginal bleeding
  • Cancer of the breast or uterus

Make sure to discuss your family history with your doctor. The vast majority of women with a family history of breast cancer can take the pill. It is important for your doctor to know if you have a first-degree relative (parent, brother, sister, child) who has had blood clots in the legs or lungs. However, most women with such a family history can take birth control pills. The risks of having a serious medical problem with unintended pregnancy is always much higher than the risks associated with taking the pill.

The pill can raise your blood pressure if you have a history of hypertension (high blood pressure). This needs to be watched closely. Women who have several risk factors for heart disease (smoking, high blood pressure, obesity) may want to consider an alternative highly effective contraceptive option, such as a progestin-only arm implant or an intrauterine device (IUD).

Are there any health benefits from taking the pill?

There are many health benefits from using a birth control pill. Typically, the longer that a woman uses the pill, the more the pills help protect from certain conditions. The birth control pill has been shown to:

  • Decrease the risks of ovarian and uterine cancers.
  • Improve death rates in women.
  • Lighten menstrual flow.
  • Improve anemia (low blood count).
  • Treat premenstrual syndrome (PMS) and premenstrual dysphoric disorder (PMDD).
  • Prevent menstrual migraines.
  • Treat acne.

Is it okay to take other drugs while taking the pill?

Some drugs can stop the pill from working properly. Tell your doctor about all of the medicines you are taking, including herbal medications and anti-seizure medications. Women with HIV may safely take the pill, but certain HIV medications can make the pill less effective.

How do mini-pills (progestin-only pills) work?

Mini-pills work similarly to combination (estrogen- and progestin-containing) pills. However, they are less effective in preventing ovulation. A pill is taken every day, without a placebo break. Because the hormones in progestin-only pills are cleared from the body much more quickly, it is extremely important to take the mini-pill at the same time each day.

How effective are mini-pills?

Approximately 9 out of 100 women have an unintended pregnancy each year while taking the mini-pill.

What is emergency contraception or Plan B?

Emergency contraception—also called the "morning after pill"—is a form of birth control that may be used by women within 120 hours of having unprotected sex. There are two types of emergency contraception pills available in the United States: progestin-only (such as Plan B One-Step® or Next Choice®) and ulipristal acetate (ella®).

If dedicated emergency contraception pills are unavailable, women can—under a doctor’s care—use higher doses of certain regular oral contraceptives. This course of treatment is also called the Yuzpe regimen. However, ulipristal and progestin-only methods are preferred over the Yuzpe regimen. Not only are they more effective, but they also cause minimal side effects such as nausea and vomiting (which are common with high-dose combined birth control pill regimens).

Another option for emergency contraception is the insertion of a copper IUD into the uterus within five days of unprotected sex. The copper IUD is 99.9% effective at preventing pregnancy when inserted after sex. It provides at least 10 years of excellent ongoing contraception.

Points to keep in mind when taking the pill:

  • Keep another form of birth control, like condoms, on hand in case you forget to take a pill.
  • Carry your pills with you if you don't always sleep at home.
  • Get your pill refills soon after you start the last pill pack. Don't wait until the last minute.
  • Birth control pills are medication. Always inform your doctor or pharmacist that you are on the pill.

There are other forms of hormonal contraception besides the pill, including:

  • The vaginal ring (NuvaRing®), which is a contraceptive ring inserted into the vagina and left in place for three weeks;
  • The weekly contraceptive patch (Ortho Evra®), which is applied to the skin once a week for three weeks a month;
  • A progestin-only arm implant (Nexplanon®);
  • The levonorgestrel-releasing IUD (Mirena®, Skyla®, Kyleena®, Liletta®), which is placed in the uterus.

Last reviewed by a Cleveland Clinic medical professional on 11/04/2016.


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