Many people question ‘how effective is the morning after pill?’, but the answer largely depends on one thing: how soon after unprotected sex the pill is taken. Beyond this, there can be some differences depending on the type you use. This article examines the two most widely used morning after pills – Levonorgestrel (generic Levonelle) and ellaOne – as well as the emergency coil, or IUD.
EllaOne is the most effective morning after pill (although the emergency coil is the most effective form of emergency contraception). It contains ulipristal acetate, a chemical that prevents pregnancy in a similar manner to levonorgestrel.
EllaOne should be taken as soon as possible after unprotected sex to maximise its effectiveness. However, ellaOne has a longer window of use than Levonorgestrel. EllaOne has to be taken within five days (120 hours) of unprotected sex – allowing 48 hours extra than Levonorgestrel.
EllaOne is taken as a single tablet. Whereas the effectiveness of Levonorgestrel starts to decrease after 12 hours, ellaOne is thought to remain up to 95% effective throughout the five day window. Unlike Levonorgestrel, ellaOne can only be taken once during the same menstrual cycle, and it can disrupt long-term contraception such as the combined pill.
Potential side effects are very rare. The most likely are irregular bleeding, headache, nausea and stomach pain, but these side-effects are rarely severe. Don’t take ellaOne if you believe you are already pregnant and bear in mind that ellaOne may interact with certain medicines. Consult the medical instructions within the packet or speak with your GP if you have major concerns.
If you vomit within three hours of taking ellaOne you must take another tablet as soon as possible. Recurrent vomiting probably means your body is rejecting the treatment. You could try Levonorgestrel provided you are within 72 hours of sexual intercourse, although Levonorgestrel’s decreasing effectiveness means the IUD is probably the better option. For further information on ellaOne click here.
Levonorgestrel is the most commonly used morning after pill. Although less effective than ellaOne, it has been around longer and costs less. Levonorgestrel is a synthetic hormone that prevents pregnancy.
Levonorgestrel is most effective when taken within 12 hours of unprotected sex, although it can be effective for up to 72 hours after sex. You should bear in mind, however, that this effectiveness decreases over time.
Levonorgestrel is thought to prevent:
- up to 95% of pregnancies if taken within 24 hours
- up to 85% if taken within 48 hours
- up to 58% if taken within 72 hours
For this reason, taking Levonorgestrel three days after unprotected sex may not leave you as well-protected as you hoped.
Levonorgestrel comes as a tablet, taken once only. However, you can take Levonorgestrel again during the same menstrual cycle if you require emergency contraception on another occasion. Levonorgestrel should not disrupt any contraception such as the combined pill. In contrast, ellaOne can only be taken once during the menstrual cycle and may disrupt your contraception (please note that you should never take Levonorgestrel and ellaOne within the same menstrual cycle as each other).
Most women experience no side effects after taking Levonorgestrel. Should side effects occur, the most common are irregular bleeding, headache, nausea and stomach pain. Certain medical conditions make Levonorgestrel unsafe to take. If you order through our site, one of our doctors will check that you are eligible beforehand.
Should you vomit within two hours of taking Levonorgestrel, you will need to take another tablet as soon as possible. If vomiting recurs then your body has probably rejected the treatment. You should seek another form of emergency contraception – mostly likely the IUD coil (see below). For further information on Levonorgestrel, click here.
The emergency IUD, or coil
The IUD is the most effective form of emergency contraception. It’s is a small T-shaped device made from plastic and copper that is inserted into the uterus to prevent pregnancy.The coil stops the egg and sperm from surviving in the womb or fallopian tubes. It is commonly used as a form of long-term contraception. However the coil is also a very effective emergency contraception – indeed more so than either Levonorgestrel or ellaOne. You can get the coil fitted within five days of unprotected sex and it will be 99.9% effective.
To have the coil fitted you must visit your GP or local sexual health clinic. There you will have an internal examination to discover the size and position of your womb. The insertion process takes between 15 to 20 minutes. The coil can be an effective form of contraception for 5 to 10 years, depending on the version used. However, if you want to remove the coil the procedure can be done at any time by a trained doctor or nurse. Once the coil is removed your fertility will return to normal.
Some women find the coil causes vaginal bleeding and pain. Most, however, experience no discomfort. Periods can be heavier although this tends to clear after a few months. The coil doesn’t prevent sexually transmitted infections so you will still need to use a condom during sex if you aren’t certain that your partner is STI-free.
The coil should not be fitted if you have:
- an untreated pelvic infection or STI
- unexplained vaginal bleeding
- certain abnormalities of the cervix or womb
The doctor or nurse fitting the coil will examine you beforehand to ensure the coil is appropriate for you. For more information, visit your GP or local sexual health clinic.
Does emergency contraception protect against STIs?
No, not at all. If you have had unprotected sex and are worried that you might have an STI then you should visit your local sexual health clinic for testing. Alternatively, our online sexual health clinic provides advice, tests and treatments for a range of STIs.
You should also remember that the morning after pill isn’t a suitable alternative to regular contraception. It is designed for one-off use. If you do not want to use long-term hormonal contraception, barrier methods such as condoms could be the answer. They are far cheaper than using emergency contraception regularly, and offer effective protection against sexually transmitted infections.