Emergency contraceptive pill

What is the emergency contraceptive pill (morning after pill)?

The emergency contraceptive pill is a pill you can take after unprotected sex to prevent pregnancy. There are 2 types of pill: levonorgestrel and ulipristal acetate, which is better known by the brand name ellaOne in the UK.

How does it work?

The morning after pill prevents or delays an egg from being released (ovulation).

When to take emergency contraception

The emergency contraceptive pill is more effective the sooner it is taken after sex. It can be taken up to 120 hours (5 days) after sex, depending on which type you take.

Different types of morning after pill

There are two types of emergency contraceptive pill:


Levonorgestrel, sometimes called Levonelle, is a single pill that you take up to 72 hours after unprotected sex. It contains the hormone levonorgestrel which is similar to the natural hormone progesterone that’s produced by the ovaries.

Ulipristal acetate/ellaOne

ellaOne is a single pill containing ulipristal acetate, which can be taken up to 120 hours (5 days) after unprotected sex. It stops or delays ovulation and disrupts the production of the hormone, progesterone. If you’re taking medication that contains progestogen, this may reduce the effectiveness of ulipristal acetate. Your healthcare professional or pharmacist may recommend you use a pill containing levonorgestrel or get an emergency IUD instead.

How effective are morning after pills?

The morning after pill is not 100% effective. It’s more effective the sooner it is taken after sex. It’s mainly effective if taken before you ovulate (release an egg).

A clinical consultation will determine what types of emergency contraception are right for you. The emergency IUD (copper coil) is always more effective than the emergency pill.

Morning after pill side effects

Neither type of emergency contraceptive pill has any serious or long-term side effects, but they can give you a headache or make you feel sick. You may also find your next period is earlier, later or heavier than usual.

Things to consider when taking the emergency contraceptive pill?

  • If you vomit within 2 hours of taking Levonelle or 3 hours of taking ellaOne, they may not work. Contact your emergency contraception provider who may recommend another dose or advise you to have an emergency IUD fitted.
  • Though you can use them more than once in a monthly cycle, emergency contraceptive pills aren’t meant for frequent use. You might want to consider a routine contraception option if you need something longer-term.
  • It doesn’t protect you from any future unprotected sex, so you might want to explore longer-term contraceptive options.
  • Emergency contraception does not protect you from sexually transmitted infections (STIs).
  • As the morning after pill is not 100% effective, you may want to take a pregnancy test to make sure it’s worked, particularly if your next period is lighter or shorter than usual or doesn’t arrive.
  • Emergency contraception doesn’t work if you’re already pregnant

Where can I get the free morning after pill?

You can get the emergency contraceptive pill for free from sexual health clinics, A&E / NHS Walk in departments, some GP practices and some pharmacies.

If you live in London, you can now take an online consultation and order the emergency contraceptive pill from SHL.UK for free. Register or Login for more information.

It is also available to buy at pharmacies.

Other emergency contraception options

The emergency IUD or copper coil can be fitted by a health professional up to 5 days after sex or up to 5 days after your estimated ovulation date (when you release an egg).

Reviewed by our clinical team: December 2020 (next review date: April 2022)