Emergency contraceptive pill

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 emergency contraceptive pill is the most popular method of emergency contraception, and can be bought without prescription from most pharmacies. It is most effective when within 24 hours of unprotected sex.

How it works

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.

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

There are two different types of emergency contraceptive 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

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.

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.


Does it matter how long I wait to take the emergency contraceptive pill after having unprotected sex?

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

What information will I have to give if I want to get emergency contraception?

If you need emergency contraception for recent unprotected sex, you will be asked:

  • When you have had unprotected sex in your current menstrual cycle.
  • The date your last period started.
  • Sometimes you'll be asked the usual length of your cycle (from the start of one period to the next).
  • Details of any contraceptive failure (such as how many pills you may have missed, and when).
  • If you use medication.
  • Your medical history and sexual health history.

What if I take emergency contraceptive pills but my period doesn’t start as usual?

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.

What if I can’t remember exactly when I had unprotected sex or when my last period was?

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.

Can I get the emergency contraceptive pill in advance?

Ask your GP or nurse if you want to get the emergency contraceptive 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

Who can take the emergency contraceptive pill?

Most people can take the emergency contraceptive pill. This includes people who cannot usually use hormonal contraception, such as the combined pill and contraceptive patch. However, emergency contraceptive pills can be less effective if you are taking certain medicines. Speak to your clinician, GP or pharmacist about this, and read the information that comes with your medicine.

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

  • 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

Can I take emergency contraception whilst breastfeeding?

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

How will the emergency contraceptive pill affect my normal contraception?

The emergency contraceptive 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 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

How will Ulipristal acetate (UPA) affect my next period?

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.

How will Levonorgestrel (LNG) affect my next period?

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.

Who is Ulipristal acetate (UPA) suitable for?

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).