How many birth control pills can be taken after unprotected sex for emergency contraception?

Originally Published: May 1, 1994 - Last Updated / Reviewed On: March 20, 2014
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Dear Alice,

Is there any way for a woman to combine her birth control pills to get the same effect as PCC (post-coital contraception)? If so, what is the dosage? For example, could I take three or four or even all of my birth control pills at once in order to get the same effect? I need to know the answer: How many pills will equal one PCC dosage? Please tell me because otherwise I'm going to take the whole month's worth at once.

—Desperate

Dear Desperate,

"Post-coital contraception," "the morning after pill," and "emergency contraception" are all names given to hormonal medication that is taken after unprotected sex to prevent pregnancy. Some birth control pills that contain ethinyl estradiol and levonorgestrel are considered safe and effective for use as emergency contraception (EC). However, if a woman has been taking her birth control pills regularly and as directed by her health care provider, taking them in the higher emergency contraceptive dose isn't necessary to prevent pregnancy.

The number of combined hormonal birth control pills to be used as emergency contraception depends on how much of each hormone the pills have, which varies by brand. Studies have shown that 100 micrograms (mcg) of ethinyl estradiol together with 0.5 milligrams of levonorgestrel taken in two doses 12 hours apart is approximately 75 percent successful at preventing pregnancy, if taken within 5 days (120 hours) after sex that occurred when a birth control method failed or wasn’t used. For more information, you can visit Princeton University’s emergency contraception website. It might also be a good idea to talk to a health care provider for guidance if you choose to take this route. Taking an entire pill-pack, however, isn't recommended since taking so many pills at once will likely cause vomiting. Since the effectiveness of these pills to prevent pregnancy depends on their being absorbed into the bloodstream, they won't work if they're thrown up.

The sooner after sex the pills are taken, the more effective they are at preventing pregnancy. Side effects may include temporary nausea, but otherwise, the risks associated with taking these combined emergency contraception are the same as those associated with daily birth control pills and are minimal.

The one-pill, progestin-only formulation of EC, including Plan B One-Step and its generic versions My Way and Next Choice, are now available over-the-counter. This means you will be able to find them on-the-shelf in the family planning aisle at your local pharmacy or drugstore. Both brand name and generic progestin-only EC is 88 percent effective at preventing pregnancy if taken within 72 hours (as stated on the label) after sex and has fewer side-effects than daily combined hormonal birth control pills taken as EC.

As you’ve mentioned in your question, you are currently taking a daily birth control pill. Is it difficult to remember to take it each day? Are you bothered by the side effects? Are you curious about other birth control options available? If you find yourself saying yes to any of these questions, it may be time to speak with your health care provider about another option long-term birth control method that is a better fit for you. If you are a Columbia student, you can make an appointment at Medical Services (Morningside) or at the Student Health Service (CUMC). For more information about what birth control options are available, check out the Planned Parenthood website.

Hope this helps!

Alice