How Effective is the Morning After Pill?
The morning after pill is considered most effective when taken at the correct time after unprotected sex. How effective the morning after pill is for you will depend on which one you’re taking and when you’re taking it. By understanding how effective the morning after pill is, knowing which pill is right for you and when to take it is one of the most effective ways to prevent pregnancy after unprotected sex.
Comparing Emergency Contraception Options
The type of morning after pill you take and when you take it will change how effective it is. Some morning after pills are more effective when taken within 24 hours of unprotected sex but less effective when taken within 25-72 hours. Others can still be taken up to 5 days after unprotected sex, while still being effective. Regarding specific methods:
- Levonelle: This branded version of levonorgestrel is effective for up to 72 hours after unprotected sex. However, Levonelle is considered most effective when taken within 24 hours.
- ellaOne: EllaOne is up to 98-99% effective and can be taken up to 5 days (120 hours) after having unprotected sex.
- The IUD (coil): The IUD is the most effective kind of emergency contraception. Trials indicate the failure rate for the IUD as emergency contraception is lower than 0.1%, meaning that less than 1 in every 1,000 women will fall pregnant.
Levonelle Effectiveness Timeline
Manufacturer’s studies have shown the effectiveness of Levonelle to be as follows:
- 95% effective if you take it within 1 day (24 hours) of unprotected sex.
- 85% effective if you take it within 2 days (25-48 hours).
- 58% effective after 3 days (49-72 hours).
How the Morning After Pill Works
The morning after pill delays the release of an egg from an ovary, stopping you from becoming pregnant. Levonelle contains levonorgestrel, a synthetic version of the natural hormone progesterone, while ellaOne contains ulipristal acetate, which stops progesterone working normally. If you haven’t yet ovulated, then the sooner you take the morning after pill, the higher your chances are of avoiding pregnancy as there’s less chance of an egg being released. It is important to note that the morning after pill is not an abortion pill; it works by preventing a pregnancy from happening, not terminating a fertilised egg.
Factors That Can Make the Pill Less Effective
The main things that can make the morning after pill less effective are timing and body mass index. The effectiveness of both ellaOne and Levonelle can be reduced if you have a high BMI. Both types of morning after pill are less effective when you have a higher BMI. If your BMI is between 26-30 or your weight is between 70-85kg then EllaOne will be the more effective morning after pill for you. Additionally, if you think you may have already ovulated, you should speak to your doctor about having an emergency IUD fitted, as this can be fitted up to 5 days after your earliest possible ovulation date.