Skip to main content

Emergency contraceptive pill

A woman can get pregnant if a man’s sperm reaches one of her eggs (ova). Contraception tries to stop this by keeping the egg and sperm apart or by stopping eggs being produced.

Emergency contraception can prevent pregnancy after unprotected sex or if your contraceptive method has failed - for example, a condom has split or you've missed a pill. The sooner you take emergency contraception after unprotected sex, the more effective it will be.

One method of emergency contraception is the emergency contraceptive pill.  There are 2 kinds of emergency contraceptive pill. Levonelle has to be taken within 72 hours (three days) of sex and ellaOne. One has to be taken within 120 hours (five days) of sex. Both pills work by preventing or delaying ovulation (release of an egg).

Emergency contraception does not protect against sexually transmitted infections (STIs).

Where can I get emergency contraception from?

All of our clinics provide emergency contraceptive pills. If you need emergency contraception you will need to register for an emergency appointment  slot at one of our clinics. We open these appointments daily or you can telephone our Freephone number on 0300 123 5474 for more advice about where you can be seen.

If you are aged 19 or under, Brook clinic runs every day except for Sunday. Book an appointment at one of our clinics or come along to a Walk-in and wait clinic.*

*Please note our Walk-in and wait slots are limited and can on occasion incur a 2 hour wait.

We work in partnership with some local Wirral pharmacies, many of which can also offer free Emergency Contraception to save you coming to clinic.

The list of pharmacies and contact numbers can be found here. It is always advisably to contact the pharmacy in advance to make sure there is somebody on duty who can help you.


You can also get the emergency contraceptive pill from your GP, NHS Walk-in centre, Minor Injuries Centres and some pharmacies*. Schools and colleges also have drop in services.

If you need emergency contraception outside clinic opening times please contact:

All Day Health Centre, Arrowe Park Hospital - 0151 201 4188 (8.00am - 9.45pm, 7 days a week)

Victoria Central Walk-in Centre, Wallasey - 0151 604 7296 (8.00am - 10.00pm 7 days a week, including bank holidays)

About emergency contraception

  • The emergency contraceptive pills (Levonelle or ellaOne) are effective at preventing pregnancy if they are used soon after unprotected sex
  • The sooner you take either one, the more effective it will be
  • They can both make you feel sick, dizzy or tired, or give you a headache, tender breasts or abdominal pain
  • They can make your period earlier or later than usual. If you’re sick (vomit) within two hours of taking Levonelle, or three hours of taking ellaOne, seek medical advice as you will need to take another dose or have an IUD fitted
  • There are no serious side effects of using emergency contraception
  • Emergency contraception does not cause an abortion

How the emergency pill works


Levonelle contains levonorgestrel, a synthetic version of the natural hormone progesterone. In a woman’s body, progesterone plays a role in ovulation and preparing the uterus for accepting a fertilised egg.

It’s not known exactly how Levonelle works, but it’s thought to work primarily by preventing or delaying ovulation. It does not interfere with your regular method of contraception.


ellaOne contains ulipristal acetate, which stops progesterone working normally. It prevents pregnancy mainly by preventing or delaying ovulation.`

Levonelle and ellaOne do not continue to protect you against pregnancy. This means that if you have unprotected sex at any time after taking the emergency pill you can become pregnant.

Even if you are starting or continuing another method of hormonal contraception, it may not be effective immediately. You will need to use condoms or avoid sex until the contraception is working effectively.

The time it takes for contraception to become effective depends on the emergency contraceptive pill and the method of hormonal contraception being started. Your doctor or nurse will tell you when you can start hormonal contraception and how long you will need to take additional precautions to prevent an unintended pregnancy.

Levonelle and ellaOne are not intended to be used as a regular form of contraception. However, you can use emergency contraception more than once in a menstrual cycle if necessary.

How effective is the emergency pill at preventing pregnancy?

It can be difficult to know how many pregnancies the emergency pill prevents, because there is no way to know for sure how many women would have got pregnant if they did not take it.

A study published in 2010 showed that of 1,696 women who received the emergency pill within 72 hours of sex, 37 became pregnant (1,659 did not). Of 203 women who took the emergency pill between 72 and 120 hours after unprotected sex, there were three pregnancies.

Find out more about the research on the effectiveness of both emergency contraception pills.

However, it's important to remember that the sooner you take emergency contraception after sex, the more effective it will be.

Download the Family Planning Association guide to emergency contraception.