How does the morning after pill work?

The morning after pill works by preventing, or delaying, ovulation. This means that when the sperm enter the fallopian tubes, there is no egg there to fertilise so no pregnancy can occur. By taking emergency contraception as soon as possible after unprotected sex you reduce your chances of ovulating. If ovulation takes place between unprotected sex and taking the morning after pill, the pill will be ineffective in preventing pregnancy.

If you have taken emergency contraception but your next period doesn’t arrive, or is over 7 days late, then you should take a pregnancy test.

Of course you can. The morning after pill is free if you are under 18 years old, and you can get it anonymously at pharmacies, family planning centres, or from your school nurse.

The sooner you take the morning after pill the more effective it will be. Pills containing levonorgestrel are effective for up to 72 hours (3 days), whereas ellaOne is effective for up to 120 hours (5 days). With either of these emergency contraceptive pills, the longer you leave it, the less effective it will be, so don’t delay.

If you vomit within three hours of taking ellaOne, it will not be effective and you will need to take another pill.

Yes! This nickname is given to ellaOne^® because it can be effective for up to 5 days (120 hours) after unprotected sex. Despite the nickname, it is important to remember that the longer you wait, the less effective emergency contraception will be. Any morning after pill is most effective when taken within 24 hours of unprotected sex.

Any medicine can come with potential side effects but these will vary from person to person. Generally, the morning after pill is very well-tolerated. The most common side effects are headaches, nausea (feeling sick), abdominal pain, fatigue, dizziness and painful periods, but everyone is different.

ellaOne^® contains ulipristal acetate which will affect the hormones that control ovulation in your current menstrual cycle. This means it can change the date your next period arrives, or make it heavier or lighter than usual. By your next menstrual cycle everything will return to its usual pattern. We recommend using a barrier method of contraception – like a condom or diaphragm – until your next period arrives. If your next period is more than 7 days late, if your period is abnormal in character or if there are symptoms suggestive of pregnancy or in case of doubt, you should take a pregnancy test.