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Medicine guide

Emergency contraception: levonorgestrel, ulipristal and the IUD

Emergency contraception can stop a pregnancy after sex without contraception or when contraception has failed. There are two pills, levonorgestrel (Levonelle) within 3 days and ulipristal acetate (ellaOne) within 5 days, and the copper IUD within 5 days is the most effective option. The sooner it is used, the better it usually works. It does not protect against sexually transmitted infections.

Last checked: 2026-10-03

Key facts

At a glance.

  • Levonorgestrel

    Brand Levonelle; take within 3 days (72 hours) after sex.

  • Ulipristal acetate

    Brand ellaOne; take within 5 days (120 hours) after sex.

  • Copper IUD

    Within 5 days (120 hours); the NHS calls it the most effective type of emergency contraception.

  • Effectiveness

    Around 1 to 2 women in every 100 who take an emergency contraceptive pill will get pregnant.

  • Vomiting

    If you vomit within 2 hours of taking the pill you may need another dose as soon as possible.

  • Cost and access

    Free from NHS sexual health clinics, GP surgeries, some walk-in centres and participating pharmacies, and also sold by many pharmacies.

What emergency contraception is

The emergency contraceptive pill, sometimes called the morning-after pill, can stop a pregnancy happening after sex without contraception or if contraception fails. The NHS says it must be taken within 3 or 5 days after sex, depending on the type, and that earlier use is usually more effective.

It is not intended as a regular method and it does not protect against sexually transmitted infections, including HIV; condoms remain necessary for that.

The three options

Two pills are available. Levonorgestrel, sold as Levonelle, is a single pill taken within 3 days (72 hours) of sex. Ulipristal acetate, sold as ellaOne, is a single pill taken within 5 days (120 hours).

The third option is the copper IUD, a small plastic T-shape inserted into the womb within 5 days (120 hours) of sex. The NHS says it is the most effective type of emergency contraception. Research quoted by the NHS shows around 1 to 2 women in every 100 who take an emergency contraceptive pill will become pregnant.

Emergency contraception options and time limits
OptionBrandUse within
Levonorgestrel pillLevonelle3 days (72 hours)
Ulipristal acetate pillellaOne5 days (120 hours)
Copper IUDNot applicable5 days (120 hours)

Who can take it, and who needs advice

Most people can use the emergency pill, even if they cannot use other hormonal contraception, and it can be used while breastfeeding. A doctor, nurse or pharmacist can talk through whether it is suitable.

The NHS lists people who should seek advice first: those taking steroid medicines for asthma, those who are overweight, anyone on TB, epilepsy or HIV medicines, and users of griseofulvin or St John's wort. People on certain medicines may be advised to have an IUD fitted instead.

Taking it and what to do if you vomit

Take one pill as a single dose. If you vomit within 2 hours after taking it, you may need another dose as soon as possible, so speak to a pharmacist or clinic.

Ask a pharmacist or clinic about your regular contraception. The NHS notes that the combined and progestogen-only pills can affect how some emergency contraception works.

Side effects

The NHS says common side effects include headache, feeling sick and period-like pain and cramping. It describes the emergency pill as very safe, with serious side effects rare.

Where it is supplied and age limits

The NHS says emergency contraception is free from sexual health clinics, GP surgeries, walk-in centres, young people's services and pharmacies that offer an NHS service. Many pharmacies also sell it in shops and online. Contraception is free and confidential, including for people under 16, and no minimum age is stated.

Suspected side effects can be reported through the Yellow Card scheme.

Frequently asked

Questions people ask.

Quick, plain-English answers to the questions we hear most.

  • How long do I have to take the morning-after pill?

    Levonorgestrel (Levonelle) within 3 days (72 hours) and ulipristal acetate (ellaOne) within 5 days (120 hours) after sex. The sooner you take it, the more effective it usually is.

  • Which is the most effective emergency contraception?

    The NHS says the copper IUD is the most effective, and it can be fitted within 5 days (120 hours) after sex.

  • What are the chances of pregnancy after taking it?

    The NHS quotes around 1 to 2 women in every 100 who take an emergency contraceptive pill getting pregnant.

  • What if I am sick after taking it?

    If you vomit within 2 hours you may need to take another dose as soon as possible. Ask a pharmacist or clinic.

  • Can I take it while breastfeeding?

    Yes. The NHS says people who are breastfeeding can use it.

  • Do any medicines affect it?

    Steroid medicines for asthma, TB, epilepsy and HIV medicines, griseofulvin and St John's wort mean you should seek advice, and an IUD may be suggested instead.

  • Does weight matter?

    The NHS advises people who are overweight to seek advice, as they may be steered to a different option.

  • Does it protect against STIs?

    No. It does not protect against sexually transmitted infections, including HIV.

  • What are the side effects?

    Headache, nausea, and period-like pain and cramping. Serious side effects are rare.

Where this comes from

Sources and checking.

This guide is for information, not medical advice.

Your GP or consultant knows your history and can tell you which parts apply to you. If your symptoms are severe, rapidly worsening, or come with red-flag features, seek urgent medical care. Figures and availability change, so treat them as a guide and confirm with the provider.

Published 2026-10-03, next review 2027-10-03.

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