How effective is the morning after pill?

The emergency contraceptive pill, also called the morning after pill, will prevent 50-66% of pregnancies. The sooner you take it, the more effective it will be.

It's sometimes said that emergency contraceptive pills are more effective than this, around 97-99% effective. We don't use that figure because we do not think it gives the full story. Not everyone who takes this pill would get pregnant without it. For example, they might have had sex during a non-fertile time in their menstrual cycle.

Types of morning after pill

There are two types of emergency contraception pills, levonorgestrel and ulipristal acetate.

Ulipristal acetate is a little more effective than levonorgestrel. But it can interact with other types of hormonal contraception.

Read more about the types of emergency pill. 

The non-hormonal coil (IUD) is the most effective emergency contraception. It prevents 99% of pregnancies if you have it fitted up to 5 days after unprotected sex. And it will work as an ongoing form of contraception if you decide to keep it in.

Reviewed by Dr Paula Baraitser. Medical Director

Last updated at: 31 May 2022


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