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Can Any Woman Use Emergency Contraception?


Yes! Let Me Explain

Emergency Contraception, whether over-the-counter or prescription pills or IUD, is highly effective and safe. Here’s what you need to know:

What Is Emergency Contraception (EC)?

EC is therapy used to prevent pregnancy after an unprotected or inadequately protected episode of sexual intercourse. Examples of when EC would be useful include if a condom breaks, or if you miss two or more birth control pills in a row, or if you haven’t used any contraception. (1).

Who Can Use EC?

Anyone! Even if you have conditions that would make typical oral contraception (estrogen plus progesterone) unsafe for you – such as a history of stroke, embolism or liver disease – you can still safely use EC (2). Women who are breastfeeding may use emergency contraception as well.

How Does EC Work?

Hormonal EC medications prevent or delay ovulation (3-5) and do NOT cause abortion. EC medications work only before a pregnancy is established. By the way, though, if you are already pregnant and don’t know it when you take EC medication, there is no known risk to a developing embryo. Also, EC oral medications have no effect on your future fertility.

What Medicines Are Used for EC?

Levonorgestrel (Plan B One-Step and its generic forms such as Take Action and My Way)

Levonorgestrel is the most commonly used oral emergency contraceptive regimen. It sold over the counter and has no minimum age requirement. Like every EC method, it most effective at protecting against pregnancy if you take it as soon as possible after unprotected sex. It is labeled for use for up to 72 hours, but may have some effectiveness up to 5 days after unprotected sex (6). Levonorgestrel is much less effective in women with obesity (6).

Ulipristal Acetate (Ella, EllaOne, and Fibristal.)

Ulipristal acetate requires a prescription. This antiprogestin has two advantages over levonorgestrel: its stated effectiveness is for up to 120 hours (5 days) after unprotected sex (6), and it is more effective for women with obesity.


An IUD is an excellent form of emergency contraception, although it requires a visit with a medical provider to have it inserted. The copper IUD is highly effective if placed within 5 days of sexual intercourse and may even be effective as many as 10 days later (7). A recent study showed that levonorgestrel-containing IUDs are equally effective when used within 5 days of intercourse (8).

A high-dose estrogen–progestin emergency contraceptive regimen (“Yuzpe Method”) is not generally recommended, for three reasons:

  1. It is less effective than the other methods
  2. It is a higher-risk regimen, particularly for any women with conditions where estrogens are less safe
  3. Since the dose of hormones is so high, significant nausea and vomiting are common (9)

How Effective is EC?

EC is extremely effective, especially when taken very soon after unprotected intercourse. Approximate numbers show that IUD’s have a pregnancy rate of 0.3%, ulipristal acetate 1.4%, and levonorgestrel 2.2% (6).

Body weight influences the effectiveness of oral emergency contraception. Levonorgestrel, in particular, is less effective in women who are or obese (10). While IUD’s are an ideal form of EC if you have obesity, they do require a doctor’s visit. Ulipristal acetate especially, an even levonorgestrel, are better than nothing.

You may want to consider having a dose (or prescription) for EC on hand, since it is most effective in preventing pregnancy when used immediately after unprotected sex.

Are There Any Side Effects with EC?

Side effects are minimal and temporary. Fewer than 20% of women who take either of these medications develop nausea or headaches (6). Some women experience unpredictable light bleeding during or after the month they use, which resolves itself without treatment.

Most women get their periods within 1 week of the expected time.  If your period is more than a week late, you should get a pregnancy test.

Can EC Be Used More Than Once?

You can use EC may be used more than once, even within the same menstrual cycle. It’s important to realize, though, that EC is generally less effective than long-term methods of birth control.

While some women use levonorgestrel as a long-term form of birth control by taking one tablet immediately before and after each episode of intercourse, the pregnancy rate is 5.4% (11)

Also, keep in mind that if you have unprotected sex, you should be tested for sexually transmitted infections.

Is There Anything I Need to Do After Using EC?

After having unprotected sex, you should be tested for sexually transmitted infections. You should also have a pregnancy test if your period is more than a week late, and you should consider having a discussion about getting started on an effective method of long-term birth control.

When Should I Resume Regular Contraception After EC?

You should use barrier contraception (eg, condoms, diaphragms, and spermicides) to prevent pregnancy for at least 7 days after using EC oral medications. If you’re usually on birth control pills, you can resume them right away if you’ve taken levonorgetrel. But if you’ve taken ulipristal acetate, then wait at least 5 days before you start your birth control pill again (12). This is because ulipristal acetate may make birth control pills less effective.  An IUD is effective contraception immediately.


  • Emergency Contraception (EC) is extremely safe, even for women who cannot use birth control pills.
  • EC methods are most effective when used as soon as possible after unprotected intercourse.
  • EC delays or prevents ovulation – it does not cause abortion.
  • No matter where you are in your menstrual cycle, EC is a good idea if you’ve had unprotected sex.
  • You may want to consider having a dose (or prescription) for EC on hand, since it is most effective in preventing pregnancy when used immediately after unprotected sex.
  • Oral emergency contraception may be used more than once, even within the same menstrual cycle.
  • Increased body weight reduced the effectiveness of oral EC, but not IUD’s.
  • After using EC, get a pregnancy test if your next period is more than a week late.

Recommended resource for further questions:



(1)ACOG Clin Bulletin 152.

(2)Centers for Disease Control and Prevention (CDC). U S. Medical Eligibility Criteria for Contraceptive Use, 2010. MMWR Recomm Rep. 2010 Jun 18;59(RR-4):1-86. PMID: 20559203.(3)Grimes DA, Raymond EG. Emergency contraception. Ann Intern Med. 2002 Aug 6;137(3):180-9. doi: 10.7326/0003-4819-137-3-200208060-00010. PMID: 12160366.(4)Croxatto HB, Fuentealba B, Brache V, Salvatierra AM, Alvarez F, Massai R, Cochon L, Faundes A. Effects of the Yuzpe regimen, given during the follicular phase, on ovarian function. Contraception. 2002 Feb;65(2):121-8. doi: 10.1016/s0010-7824(01)00299-2. PMID: 11927114.(5)Durand M, del Carmen Cravioto M, Raymond EG, Durán-Sánchez O, De la Luz Cruz-Hinojosa M, Castell-Rodríguez A, Schiavon R, Larrea F. On the mechanisms of action of short-term levonorgestrel administration in emergency contraception. Contraception. 2001 Oct;64(4):227-34. doi: 10.1016/s0010-7824(01)00250-5. PMID: 11747872.(6)Glasier AF, Cameron ST, Fine PM, Logan SJ, Casale W, Van Horn J, Sogor L, Blithe DL, Scherrer B, Mathe H, Jaspart A, Ulmann A, Gainer E. Ulipristal acetate versus levonorgestrel for emergency contraception: a randomised non-inferiority trial and meta-analysis. Lancet. 2010 Feb 13;375(9714):555-62. doi: 10.1016/S0140-6736(10)60101-8. Epub 2010 Jan 29. Erratum in: Lancet. 2014 Oct 25;384(9953):1504. PMID: 20116841.(7)Turok DK, Godfrey EM, Wojdyla D, Dermish A, Torres L, Wu SC. Copper T380 intrauterine device for emergency contraception: highly effective at any time in the menstrual cycle. Hum Reprod. 2013 Oct;28(10):2672-6. doi: 10.1093/humrep/det330. Epub 2013 Aug 14. PMID: 23945595.(8)Turok DK et al. Levonorgestrel vs. Copper Intrauterine Devices for Emergency Contraception. N Engl J Med 2021; 384:335-344
DOI: 10.1056/NEJMoa2022141
(9)Cheng L, Che Y, Gülmezoglu AM. Interventions for emergency contraception. Cochrane Database of Systematic Reviews . 2012, Issue 8. Art. No.: CD001324. DOI: 10.1002/14651858.CD001324.pub4.(10)Kapp N, Abitbol JL, Mathe H, Scherrer B, Guillard H, Gainer E, et al. Effect of body weight and BMI on the efficacy of levonorgestrel emergency contraception. Contraception 2015;91:97–104.(11)Halpern V, Raymond EG, Lopez LM. Repeated use of pre- and postcoital hormonal contraception for prevention of pregnancy. Cochrane Database Syst Rev. 2014 Sep 26;2014(9):CD007595. doi: 10.1002/14651858.CD007595.pub3. PMID: 25259677; PMCID: PMC7196890.(12)U.S. Food and Drug Administration. Ulipristal acetate tablet: highlights of prescribing information. Silver Spring (MD): FDA; 2015. Available