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Morning after Pill – Emergency Contraceptive Plan B


Description of the Morning After Pill (Plan B):

Often referred to as the morning after pill, Plan B is a form of emergency contraception. Plan B can be used after intercourse to prevent pregnancy. It is important to remember that Plan B does not protect against any STDs, including HIV.

How the Morning After Pill (Plan B) Works:

Plan B works like a regular birth control pill. It prevents pregnancy mainly by stopping the release of an egg from the ovary, and may also prevent the fertilization of an egg (the uniting of sperm with the egg). Plan B may also work by preventing it from attaching to the uterus. It is important to know that Plan B will not affect a fertilized egg already attached to the uterus; it will not affect an existing pregnancy.

Plan B is not the same thing as RU-486 (called the abortion pill).

How to use the Morning After Pill (Plan B):

Plan B is easy to take. There are two pills.

  • Take the first tablet as soon as possible within 3 days (72 hours) after unprotected sex.
  • Take the second tablet 12 hours after you take the first tablet.

The sooner you take the first pill after having unprotected intercourse the more effective it will be.

Failure Rates for the Morning After Pill (Plan B):


If it is taken within 72 hours after unprotected sex, it will decrease the chance that you will get pregnant by 89%, meaning 7 out of every 8 women who would have gotten pregnant will not get pregnant.

Plan B is most effective if taken soon after unprotected intercourse. If you are having intercourse and using a reliable form of birth control, you may still want to find out where to get a prescription for Plan B in case of emergency.

Cost of the Morning After Pill (Plan B):

Fees may be less at family planning clinics and health centers. Some use a sliding scale based on income. Costs vary from community to community, based on regional and local expenses. Contact your nearest Planned Parenthood health center at 1-800-230-PLAN for information about costs in your area. Costs also depend on which of the following services are needed. The cost for Plan B could be anywhere from $10 - $35.

Where to get the Morning After Pill (Plan B):

In the U.S. you require a prescription for Plan B. Some hospitals and pharmacists refuse to prescribe Plan B. If you don’t have a regular doctor you can go to for a prescription, you may want to contact Planned Parenthood (call 1-800-230-PLAN) to see if they have a clinic in your area they can recommend.

Despite scientific agreement that it should be available, the FDA continues to delay making Plan B available without prescription.

Side Effects of the Morning After Pill (Plan B) May Include:

  • nausea
  • vomiting
  • abdominal pain li]tiredness
  • headache
  • menstrual changes
  • dizziness
  • breast tenderness

Things to Watch out for with the Morning After Pill (Plan B):

  • Some women may have their period earlier or later than their normal cycle. If your menstrual cycle is delayed more than one week, you may be pregnant.
  • If you vomit within an hour of taking either dose of Plan B you need to retake the dose.
  • Remember, if you are already pregnant Plan B will not work, as it does not affect an existing pregnancy.

More Contraception Profiles

Published December 9, 2005.

Contraception Information on About.com:

The following information is compiled from a variety of sources, including the CDC, information from drug manufacturers, Planned Parenthood, and Family Health International.

We strive to keep this information up to date, but new studies and information about side effects and effectiveness may not be reflected immediately in this information. This should be used as a guide only, and a health care professional should be consulted when considering a new or changed contraceptive method.

Updated December 18, 2005.

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