What is emergency contraception (EC)?

Emergency contraception (EC) is a form of birth control that women can use within 72 (three days) to 120 hours (five days) — depending on the type of medication — of having unprotected vaginal sex. EC pills are a safe way to prevent pregnancy.

Although it is sometimes called the morning-after pill, you don’t need to wait until the next day. If you’ve had unprotected sex and have EC available, take it right away.

Another form of emergency contraception is an intrauterine device (IUD). This type of long-term birth control is inserted into your uterus by your healthcare provider. It’s very effective and doesn’t require you to do anything additional for pregnancy prevention. Your provider can insert an IUD after unprotected sexual intercourse to prevent pregnancy.

When do I use emergency contraception (EC)?

You can use an emergency contraception method to prevent pregnancy if you recently had sex and:

  • Didn’t use a condom or other form of routine birth control.
  • Made a mistake with your regular birth control, such as forgetting to take the pill, change your patch or miss a dose of the birth control shot.
  • The condom broke or slipped off after your partner ejaculated.
  • Your partner didn’t pull out in time.

You may also choose emergency contraception in cases of rape. If someone forced you to have sex or have unprotected sex, talk to a healthcare provider about your options. A health professional can help you avoid pregnancy and get care for sexually transmitted infections (STIs). You may wish to contact the Rape, Abuse and Incest National Network (RAINN), which operates the National Sexual Assault Hotline (800-656-HOPE).

What emergency contraception (EC) pills are available?

In the U.S., two types of EC pills are available:

  • Progestin-only (levonorgestrel): Plan B One-Step® or Next Choice™.
  • Ulipristal acetate: ella®.

It’s important to know that these two types of emergency contraception have different windows of time during which they are most effective at preventing pregnancy. Progestin-only pills are typically the most effective at preventing pregnancy within the first 72 hours (three days) after unprotected sexual intercourse. Ulipristal acetate has a slightly longer window of time — 120 hours (five days). You will have the best results with either medication when you take it as soon as possible after intercourse.

Levonorgestrel (Plan B One-Step®) is available over-the-counter. Ulipristal acetate (ella®) is only available by prescription.

Are emergency contraception (EC) pills safe?

Yes. Millions of people have safely used EC for more than 30 years.

What if I don’t have access to emergency contraception pills?

If you can’t get emergency contraception pills, talk to your healthcare provider. Under your provider’s care, you can take higher doses of oral contraceptives (birth control pills). This type of treatment is called the Yuzpe regimen.

However, ulipristal and progestin-only pills offer advantages over the Yuzpe regimen, including:

  • Better effectiveness.
  • Minimal side effects (such as nausea and vomiting, common with high doses of birth control pills).

Reach out to your healthcare provider before taking a higher than normal dose of birth control pills.

Can an IUD be used for emergency contraception (EC)?

A copper intrauterine device (IUD), such as Paragard®, can be an emergency contraception option. It works if your provider inserts it within five days of unprotected sex. The copper IUD is 99.9% effective at preventing pregnancy when inserted after sex. It gives you at least 10 years of effective ongoing contraception.

What if I normally take hormonal birth control but forgot my pills?

If you made a mistake with your hormonal birth control, then Plan B One-Step® or the copper IUD are better EC options than ella®.

How does emergency contraception (EC) work?

Typically, you don’t get pregnant immediately after having sex. After sex, sperm lives in your body for up to five days. If you ovulate (release an egg) during those five days, sperm can meet the egg and fertilize it, resulting in pregnancy.

EC pills prevent ovulation — they stop your ovary from releasing an egg. So if you’ve already ovulated, EC won’t work. That’s why it’s important to take the pill as soon as possible. Since you may not know exactly when you ovulate, take the pill as soon as you can.

The IUD is more effective because sperm doesn’t like the copper in the IUD. So even if you have ovulated, an IUD makes it harder for sperm to swim to meet the egg.

How is emergency contraception (EC) available?

You can get ulipristal acetate by prescription only. It is available for patients of all ages.

You can purchase progestin-only EC pills over-the-counter. There are no age restrictions on buying these medications. They are available to people of any gender. You’ll usually find them in the aisle near pregnancy tests and ovulation kits. Sometimes, pharmacies keep them behind the counter, but you can buy them without a prescription. Just ask the pharmacist.

A few pharmacies will not sell emergency contraception. You can ask the pharmacist to tell you where to find a pharmacy that will. You can also call your healthcare provider for advice on where to get an over-the-counter EC.

Names of EC pills include:

  • Plan B One-Step®.
  • Take Action®.
  • Next Choice One Dose®.
  • My Way®.
  • Generic versions.

How effective is emergency contraception (EC)?

EC pills are about 89% effective if you take them within 72 hours (three days) of unprotected sex. You can take them up to five days after intercourse, but the sooner you take them after sex, the more effective they are. No EC method is 100% effective against pregnancy.

What factors might affect the effectiveness of emergency contraception (EC) pills?

If you carry excess weight, over-the-counter (OTC) pills may be less effective. Talk to your doctor about a prescription for ella® or a copper IUD. But if you can’t get one of those more effective methods within five days of intercourse, take the OTC medication.

Is one emergency contraception (EC) method more effective than another?

The prescription brand ella® is more effective than OTC methods because it works closer to the time of ovulation. The copper IUD is most effective of all, working 99% of the time, no matter your weight. But use the most effective method you have available. The advantage of OTC pills is that they are easier for most people to access. IUDs and ella® require you to see a healthcare provider.

What type of emergency contraception (EC) is best for me?

The most effective EC method for you depends on:

  • When you had sex.
  • Which type is easiest for you to get.
  • Your weight.
  • If you’re breastfeeding.
  • If you used the pill, patch or ring in the last few days.
  • If you’ve have malabsorption or a prior bariatric surgery.

Does emergency contraception (EC) cause side effects?

If you take emergency contraceptive pills, you may experience some side effects, but they are usually short-lived. Symptoms of emergency contraception pills can include:

EC pills may also affect your next period. They may cause your period to be early or late. You may also get some spotting (bleeding between periods).

The copper IUD can cause other side effects, including menstrual pain and heavy bleeding. Your provider may prescribe a medication to lighten the flow. These effects mostly happen in the first few months with the IUD. If they go on longer than a year, talk to your provider about what to do.

Can I use two types of emergency contraception (EC) together?

Don’t use two different types of EC, such as Plan B® and ella®, at the same time. They may end up working against each other and not preventing pregnancy. And take only the necessary dose. Taking more can make you feel sick but won’t offer extra protection.

Can I still get pregnant if I take emergency contraception (EC) pills?

No EC method can 100% prevent pregnancy. You may still get pregnant, even if you took the pills right away. If you don’t get a period within a week of when you normally expect it, take a pregnancy test and contact your healthcare provider.

Is emergency contraception (EC) the same as abortion?

No. Emergency contraception is not abortion. EC pills prevent the egg and sperm from meeting by delaying ovulation. Abortion happens after the sperm has fertilized the egg and created an embryo. Emergency contraception does not end a pregnancy — it prevents pregnancy from happening. If you are already pregnant, EC pills will not harm the pregnancy.

Can I take emergency contraception (EC) pills as a birth control method?

EC can effectively prevent pregnancy after unprotected sex. But don’t use it as your regular method of birth control. It’s not as reliable as nonemergency methods, such as an IUD, birth control pills or condoms.

What’s the best way to prevent pregnancy?

If you are sexually active, find a regular birth control method that works for you and use it as directed. Several options are available, including condoms, IUD, the pill, patch or ring. It may be a good idea to get some EC pills ahead of time to keep on hand. That way, if you need it, you can take EC as soon as possible.

Will emergency contraception (EC) prevent me from getting an STI?

No, EC pills do not protect you from getting a sexually transmitted disease or infection (STDs or STIs). Condoms are the most effective way to protect against STIs, whether you have vaginal, oral or anal sex.

When should I call the doctor?

You can purchase many types of emergency contraception without a prescription. But it’s always a good idea to speak to your healthcare provider if you have had unprotected sex. Your provider can help you:

  • Get prescription EC pills or a copper IUD, if you choose those methods of EC.
  • Figure out which ongoing birth control is best for you. (The type of EC you used will affect what type of birth control you can use right away.)
  • Receive treatment if you think you were exposed to an STI.

A note from Cleveland Clinic

If you’ve had unprotected sex, you may be worried about an unplanned pregnancy. Many emergency contraception pills, such as Plan B®, are available without a prescription to people of any age. (You need to see a healthcare provider for other EC methods, including prescription medication and a copper IUD.) EC pills, sometimes called the morning-after pill, can prevent pregnancy. Take the pill as soon as possible. If you’re sexually active but not using regular birth control, talk to your healthcare provider about effective birth control options that fit your life.

Last reviewed by a Cleveland Clinic medical professional on 10/21/2020.


  • The American College of Obstetricians and Gynecologists. Emergency Contraception. (https://www.acog.org/patient-resources/faqs/contraception/emergency-contraception) Accessed 6/7/2021.
  • Planned Parenthood. Emergency Contraception. (https://www.plannedparenthood.org/learn/morning-after-pill-emergency-contraception) Accessed 6/7/2021.
  • U.S. Department of Health & Human Services. Office of Population Affairs. Emergency Contraception. (https://www.hhs.gov/opa/pregnancy-prevention/birth-control-methods/emergency-contraception/index.html) Accessed 6/7/2021.
  • U.S. Department of Health & Human Services. Office on Women’s Health. Emergency Contraception. (https://www.womenshealth.gov/a-z-topics/emergency-contraception) Accessed 6/7/2021.

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