Emergency contraception

Emergency contraception


  • There are no serious side effects of using EC pills
  • Reduces risk of pregnancy if you haven't used contraception, or if your contraception has failed.

The emergency contraception (EC) pill (sometimes called the ‘morning after pill’) can be taken after unprotected sex to prevent pregnancy.

There are two types of hormonal emergency contraception; one which has to be taken within three days of unprotected sex, and the other within five days. The non-hormonal coil (IUD) is the most effective emergency contraception if inserted up to five days after unprotected sex.

The EC pill is by far the most popular method of emergency contraception, and can be bought without prescription from most pharmacies.

Emergency contraception effectiveness
Emergency contraception lasts for
Emergency contraception period cycle
Emergency contraception side effects

*depends how long after unprotected sex
**can make earlier or later

How it works

How to use it

Emergency contraception how

For hormonal emergency contraception:

Take one pill, within the specified time period. The EC pill is much more likely to work if you take it within 24 hours of having sex.

Emergency time

There are two different types of EC pill:

  • Levonorgestrel (LNG) has to be taken within 72 hours (three days) of sex
  • Ulipristal acetate (UPA) has to be taken with 120 hours (five days) of sex.

If you’re sick (vomit) within two hours of taking Levonorgestrel (LNG), or three hours of taking Ulipristal acetate (UPA), seek medical advice as you will need to take another dose or have a non-hormonal coil (IUD) fitted.

You will need to tell the doctor, nurse or pharmacist about the unprotected sex you have had so to they can advise on the most suitable method of emergency contraception.

Why it works

Emergency contraception why

Both types of pill contain ingredients which prevent or delay ovulation (the egg being released from your ovaries). LNG contains levonorgestrel and UPA contains ulipristal acetate.


Things to consider

EC pills or emergency IUDs do not protect against STIs. You should use condoms to protect yourself from STIs.

STIs can pass from one person to another during sex, especially if you don’t use a condom. It is a good idea to get tested, especially if you have recently changed partners. Most infections can be cured.

Using the EC pill repeatedly can disrupt your natural menstrual cycle.

What if?

You’re already using another form of contraception:

  • Ulipristal acetate (UPA) may prevent other types of hormonal contraception from working for a week after use, and it’s not recommended for use more than once in a menstrual cycle
  • Levonorgestrel (LNG) does not interfere with your regular method of contraception and you can take it more than once in a menstrual cycle
  • Levonorgestrel (LNG) and Ulipristal acetate (UPA) do not protect you against pregnancy during the rest of your menstrual cycle and are not intended to be a regular form of contraception
  • The IUD will not interfere with your regular method of contraception and will continue to give you protection against pregnancy for the rest of the cycle - you can choose to keep it for ongoing contraception.

EC pills can become less effective at preventing pregnancy if:


Most women can take the EC pill. This includes women who cannot usually use hormonal contraception, such as the combined pill and contraceptive patch.

Ulipristal acetate (UPA) is not suitable for women who:

  • May already be pregnant
  • Are allergic to any of the components of the drug
  • Have severe asthma that is not properly controlled by steroids
  • Have hereditary problems with lactose metabolism.

Side effects & risks

Common Rare
Short term:

Next period earlier or later than usual.

Can make you feel sick, dizzy or tired, or give you a headache, tender breasts or abdominal pain.

Some women using Ulipristal acetate (UPA) experience painful periods, mood swings, and muscle or back pain.

Long term:


Yes, you can take EC pills while breastfeeding. You can also have the IUD fitted while breastfeeding as long as you are more than 28 days post-delivery.

Yes – Levonorgestrel (LNG) becomes less effective the longer you wait to take it. A trial undertaken by the World Health Organization (WHO) indicated that levonorgestrel (the drug in LNG) prevented:

  • 95% of expected pregnancies when taken within 24 hours of sex
  • 85% if taken within 25-48 hours
  • 58% if taken within 49-72 hours.

The EC pill will not prevent future pregnancies if you have unprotected sex again, so you should make sure you are taking your contraception correctly.

For Levonorgestrel (LNG): If you are using emergency contraception because you forgot your regular pill or did not use the patch or vaginal ring correctly, you should take your regular pill again, insert a new ring or apply a new patch. Use additional contraception, such as condoms:

  • For seven days with the patch, the ring and the combined pill
  • For two days with the progestogen-only pill.

For Ulipristal acetate (UPA): If you forgot your regular pills, did not use the patch or vaginal ring correctly, or want to start using hormonal contraception, you should wait for 5 days after taking UPA. This is because UPA can can reduce the effect of hormonal contraception.

  • Use additional contraception, such as condoms:
  • With the patch, the ring and the combined pill, for 7 days (9 days for Qlaira pill)
  • With the progestogen only pill, for two days.

Your period is likely to come on time or a few days early or late. Sometimes it can be a week late and sometimes even later. You may have some irregular bleeding after you take the pill, and before your next period. This can range from spotting to quite heavy bleeding. If your period is over a week late, take a pregnancy test.

Your period may come on time or a few days early or late. If your period is over a week late, take a pregnancy test.

The sooner you take Levonorgestrel (LNG) or Ulipristal acetate (UPA), the more effective it will be.

If your next period is more than seven days late, or is unusually light or short, contact your GP as soon as possible to check for pregnancy.

Using the EC pill repeatedly is much less effective than using a regular method of contraception. They are not intended to be a regular form of contraception.

It’s not recommended that you use Ulipristal acetate (UPA) more than once in a menstrual cycle.

If you are unsure about either of these things, and you think you may have had unprotected sex in the last 72 hours, you should take emergency contraception.

EC pills can become less effective at preventing pregnancy if you are taking other medicines (including those used to treat epilepsy, HIV and TB, other antibiotics and the herbal medicine St John’s Wort).

  • Ulipristal acetate (UPA) cannot be used if you are already taking one of these medicines, as it may not be effective
  • Levonorgestrel (LNG) may still be used, but the dose may need to be increased – your doctor or pharmacist can advise on this
  • Ask your GP, clinician or pharmacist and read the information that comes with your medicine
  • Ulipristal acetate (UPA) may not be suitable for people who are using proton pump inhibitors such as omeprazole (antacids that regulate their stomach acid levels).

The pharmacist, doctor or nurse you see may ask for the following information:

  • When you have had unprotected sex in your current menstrual cycle
  • The date of the first day of your last period and the usual length of your cycle
  • Details of any contraceptive failure (such as how many pills you may have missed, and when)
  • If you've used any medications that may affect your contraception
  • Your medical history and sexual health history.

Ask your GP or nurse if you want to get the EC pill in advance if:

  • You are worried about your contraceptive method failing
  • You are going on holiday
  • You cannot get hold of emergency contraception easily.

Where can I get it?

You can get emergency contraception free from GPs and all sexual health clinics, as well as most NHS walk-in centres, most pharmacies, minor injuries units and A&E.

You can buy Levonorgestrel (LNG) from most pharmacies if you are aged 16 or over, and Ulipristal acetate (UPA) if you are 18 or over. You may be asked to present ID. It will cost around £30.

Contraception for the future

If you're not using a regular method of contraception, you might consider doing so in order to lower the risk of unintended pregnancy. There are several types of reliable, long lasting methods of contraception, so you don't have to think about it every day or each time you have sex.