Morning after pill and emergency contraception
Peer reviewed by Dr Colin Tidy, MRCGPLast updated by Dr Hayley Willacy, FRCGP Last updated 31 Aug 2021
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In this series:Contraception methodsContraception for women over 40Contraception after having a baby
If you have unprotected sex but do not wish to become pregnant, you may need emergency contraception. This is the term used for contraception used AFTER you have already had sex, and is commonly known as the morning after pill. However, there are several options available.
In this article:
Continue reading below
What is the morning after pill?
Emergency contraception, or the 'morning after pill', describes methods used to prevent pregnancy after you have had unprotected vaginal intercourse. There are three types of emergency contraception available to women. These are two types of pill, and the intrauterine contraceptive device (IUCD) - also called the coil. These are available free in the UK from your GP practice, and from NHS walk-in centres, as well as sexual health clinics, family planning clinics and organisations (such as British Pregnancy Advisory Service or Brook in the UK) and some pharmacies (pills only).
The coil is the most effective form of emergency contraception, so you should always consider this option. This is partly because emergency contraceptive pills are not effective if taken after ovulation has taken place.
Emergency contraception can be used:
If you have had sex without using contraception.
If you have had sex, but there was a mistake with contraception. For example, a split condom or if you forgot to take your usual contraceptive pills.
Where can I get emergency contraceptives?
In the UK the emergency contraceptive pills are available from:
Community pharmacies.
Oral emergency contraception (EC) is available free from pharmacies in Scotland and Wales, many pharmacies in England with a charge of around £16 for a single dose of Levonelle One Step® or £35 for EllaOne®, and from some pharmacies in Northern Ireland.
GP surgeries.
Sexual and reproductive health clinics and genitourinary medicine clinics.
Other sources, including:
Young people's services (where registered nurses are employed).
School nurses.
Accident and emergency department NHS walk-in centres (England only).
NHS minor injuries unit.
Online pharmacies.
The copper intrauterine device (Cu-IUCD) is available free of charge from:
Sexual and reproductive health clinics.
Young people's services (where registered nurses are employed).
GP practices.
Continue reading below
The progestogen pill
Emergency contraceptive progestogen pill
![Emergency contraception progestogen pill in packet](/_next/image?url=https%3A%2F%2Fimages.ctfassets.net%2Fxxv4b9mbhlgd%2Fimg_8964%2F515651675e9f44d419605270929de197%2F88689c72-edc2-4c15-9fc9-635a5b761580.jpg&w=1600&q=75)
By Mettiche, Public domain, via Wikimedia Commons
This is a morning after pill pill that contains levonorgestrel which is a progestogen hormone. There are several different brands available - eg, Levonelle One Step®, but they all contain the same dose of levonorgestrel. You can get it free on prescription or you can buy it from pharmacies, without a prescription. The usual dose is one pill which contains 1.5 mg of levonorgestrel. Some women need a higher dose. If you weigh more than 70 kg or your BMI is more than 26, you may need a double dose. Also if you are taking certain other medication you may need a higher dose - for example, women taking certain anti-epilepsy medicines.
When do I take the progestogen morning after pill?
Take the pill as soon as possible after unprotected sex. The morning after pill does not need to be taken 'the morning after' but is more effective the sooner you take the it. The progestogen pill may be taken up to 72 hours (three days) after sex.
What does the progestogen morning after pill do?
It is thought to work mainly by preventing or delaying the release of an egg from your ovary, which normally happens each month (ovulation). It is not thought to cause an abortion, ie it does not have an effect if an embryo has already settled (implanted) into the womb (uterus). It will not be effective if ovulation has already taken place (see below).
How effective is the progestogen morning after )pill?
Although emergency contraception is effective, it is not as reliable as regular planned contraception. Therefore, it should only be used in emergencies. The progestogen pill becomes gradually less effective the more time elapses after having unprotected sex. However, there is a good chance of preventing pregnancy if it is taken up to 72 hours (three days) after unprotected sex.
It is difficult for scientists to work out exactly how effective the progestogen pill is. This is because after having unprotected sex on one occasion, only a few women would get pregnant. It is difficult to work out which women would not have got pregnant anyway and which pregnancies were actually prevented by taking the emergency progestogen pill. If 1,000 women had unprotected sex once, around 60 to 80 would become pregnant. If all those women had taken the emergency progestogen pill, only around 6 to 26 would have become pregnant. It will, however, depend on when it is taken - both in terms of how long after unprotected sex, and how near the fertile time in the menstrual cycle.
It is sometimes used between 72 and 120 hours after unprotected sex but the chance of it working is much less if it is taken after 72 hours (three days), particularly so after 96 hours (four days).
The progestogen pill is also unlikely to be effective if taken after you ovulate, as it works by delaying ovulation. If you have a regular 28-day cycle, your ovulation is likely to happen around Day 14. (Count from the first day of your last period, and call that Day 1.) Cycles and ovulation can often be unpredictable so this may be hard to work out. If it is likely you have ovulated already, you would be better to use the coil (intrauterine contraceptive device) for emergency contraception.
Are there any side-effects with the progestogen morning after pill?
Side-effects are uncommon. However, some women feel sick for about 24 hours after taking the progestogen morning after pill. Some women are actually sick (vomit). This may be less likely to happen if the pill is taken with food.
If you vomit within three hours of taking the pill then either:
Take another pill as soon as possible. (You may need to get a further prescription, or buy another pill from the pharmacy. You may also wish to get a prescription for some antisickness tablets.)
OR a coil (intrauterine device) can be inserted (see below).
Other mild side-effects occur in some women for a short time, such as diarrhoea, dizziness and breast tenderness. There may be some change to your periods in the month after taking the pill. Your period may be early, or late, or you may get some erratic bleeding.
Who should not take the progestogen morning after pill?
Most women are able to take the progestogen pill. However, it is not suitable for all women. For example, women with a rare condition called porphyria should not take it. Also women who have very severe gut disease or a past history of ectopic pregnancy or molar pregnancy may not be able to take it.
Several other medicines can interfere with the progestogen pill, meaning it may not work as effectively. This includes:
Medicines for epilepsy - for example, phenytoin and carbamazepine.
Two antibiotics called rifampicin and rifabutin (other antibiotics do not have an effect).
An over-the-counter remedy called St John's wort, used for low mood.
Some medicines used to treat HIV and AIDS, such as ritonavir.
Make sure the doctor, nurse or pharmacist prescribing you the emergency contraception pill knows about all the other pills you are taking.
If the pill did not work and you became pregnant, there is no evidence that taking the emergency progestogen pill is harmful to the baby.
Ulipristal acetate pill
Ulipristal acetate is a type of emergency contraceptive or morning after pill that was launched in the UK in 2009. There are different brand names such as EllaOne®. It is taken as one single tablet.
When do I take the ulipristal acetate pill?
Take the pill as soon as possible after unprotected sex. As with any morning after pill, the sooner you take it, the more effective it is. However, it can be taken up to 120 hours (five days) after having unprotected sex.
How does the ulipristal acetate pill work?
Ulipristal acetate is a type of hormone contraception which seems to work by stopping or delaying release of an egg (ovulation).
How effective is the ulipristal acetate pill?
Although emergency contraception can be effective, it is not as reliable as regular planned contraception. Therefore, it should only be used in emergencies. It is most effective if you take the tablet as soon as you can after having unprotected sex. The effectiveness decreases the longer you leave before taking the tablet.
It is difficult for scientists to work out exactly how effective the ulipristal acetate pill is. After having unprotected sex on one occasion, only a few women would get pregnant. So it is difficult to work out which women would not have got pregnant anyway and which pregnancies were actually prevented by taking the emergency contraception pill. Overall, if 1,000 women had unprotected sex once, around 60 to 80 would become pregnant. If all those women had taken ulipristal acetate, only around one or two would have become pregnant. It will depend on when in the cycle it was taken. However, if all 1,000 women had had unprotected sex around ovulation time then many more than one or two would become pregnant.
Ulipristal acetate may be slightly more effective than the progestogen contraceptive pill, particularly when taken between 3-5 days after unprotected sex.
Ulipristal is also unlikely to be effective if taken after ovulation (see above). If this is the case, the intrauterine contraceptive device (IUCD) would be a better option. It is possible that it is less effective if you weigh more than 85 kg or your BMI is more than 30.
Who should not take the ulipristal acetate pill?
You may not be able to take the ulipristal acetate pill if you have severe asthma. You should not breastfeed for one week after taking this tablet. However, you can express and then discard your milk in this week so that you can continue to breastfeed afterwards.
Some other medicines can interfere with ulipristal acetate, making it less effective. If you take one of these pills it may be better to use another form of emergency contraception. Medicines which may interfere with ulipristal acetate include:
Contraceptive pills containing progestogens. This includes the progestogen emergency contraceptive pill discussed above, progestogen-only pills (POPs) and combined pills (COC), patches or rings. This means that ulipristal acetate should not be taken as emergency contraception when needed because you have missed a few days of your normal contraceptive pill. It should also not be taken if you have recently taken the levonorgestrel contraceptive pill in the previous week. Progestogens can make ulipristal acetate less effective (so you might become pregnant) if taken in the seven days before the ulipristal or the five days after it. For the same reason, you shouldn't start a contraception pill within five days of using ulipristal acetate.
Medicines for epilepsy - for example, phenytoin and carbamazepine.
Two antibiotics called rifampicin and rifabutin (other antibiotics do not have an effect).
An over-the-counter remedy called St John's wort, used for low mood.
Some medicines used to treat HIV and AIDS, such as ritonavir.
Always make sure the person prescribing you the emergency contraception pill knows about any other medication you are taking.
Are there any side-effects of ulipristal acetate?
Side-effects with the ulipristal acetate pill are uncommon. These can include headaches, feeling sick, tummy (abdominal) pains, dizziness and muscle pains. After taking it, your periods may be different for the next month. Your period may be earlier than expected, later than expected, or you may have some erratic bleeding.
If you are sick (vomit) within three hours of taking ulipristal acetate then you will need to take another tablet. You will need another prescription for this.
Continue reading below
When does a morning after pill not work
If you take them after you have produced an egg (ovulated).
If you take the progestogen pill more than 72 hours (three days) or the ulipristal acetate pill more than 120 hours (five days) after unprotected sex.
If you are sick (vomit) within three hours of taking the pill and do not take a repeat dose.
If you also had unprotected sex at an earlier time since your last period.
If you have unprotected sex again after taking emergency contraception.
The coil (intrauterine contraceptive device)
Contraceptive intrauterine device (IUD)
![Coil IUD](/_next/image?url=https%3A%2F%2Fimages.ctfassets.net%2Fxxv4b9mbhlgd%2Fimg_8965%2F3646f0ac95b39d929581ea630cad49ab%2Fa419b878-3c55-4904-8438-45e57456eb01.jpg&w=1600&q=75)
By LeiaWonder, CC BY-SA 4.0, via Wikimedia Commons
The most effective method of emergency contraception is to have an intrauterine contraceptive device (IUCD) - often known as the coil - inserted by a doctor or nurse. This can be done up to five days after unprotected sex or up to five days from the earliest possible date you could have ovulated. It has the advantage of providing ongoing contraception and is also more effective than taking hormone tablets. Fewer than 1 in 1,000 women would get pregnant after having the IUCD inserted for emergency contraception, meaning it is nearly 100% effective.
Most women can use the IUCD. Exceptions include those who have copper allergy, and those who have infections or cancer in their genital areas or womb (uterus).
You may be put off by the idea of having a device inserted, but it is worth considering this option seriously if it is important to you not to become pregnant. It is the most effective type of emergency contraception. It is also likely to be effective in situations where the pills may not work - for example, if taken after you ovulate, if you are on other medication, or whatever you weigh. In addition, you will have ongoing contraception.
See the separate leaflet called Intrauterine Contraceptive Device (The Coil) for details.
Things to know about emergency contraception and the morning after pill
Most women have their next period at about the usual time. Sometimes it is a few days earlier or later than expected. See a doctor or nurse if your next period is more than seven days late or if it is lighter than usual. A pregnancy test may be advised.
Your next menstrual cycle may also be shorter or longer than usual.
There is still a small risk of pregnancy even if you use an emergency contraceptive correctly.
You may wish to have a pregnancy test three weeks after you had unprotected sex to be sure the emergency contraception has worked. This is a particularly good plan if you have gone straight on to start hormone contraception, as your normal cycle may have been disrupted.
Follow-up after receiving emergency contraception
You may want to discuss your regular contraceptive needs with a doctor or nurse. This may be best in a relaxed follow-up consultation.
An important message
Contact a doctor urgently if you have any lower tummy (abdominal) pain or abnormal bleeding in the 2-6 weeks following use of emergency contraception. These are the main symptoms of an ectopic pregnancy. This is rare, but it is best to be aware of the possibility as it is a serious condition. Also, do a pregnancy test or contact a doctor if your next due period is more than seven days late. Contact your doctor if you have any other concerns or questions.
Further reading and references
- Richardson AR, Maltz FN; Ulipristal acetate: review of the efficacy and safety of a newly approved agent for emergency contraception. Clin Ther. 2012 Jan;34(1):24-36. doi: 10.1016/j.clinthera.2011.11.012. Epub 2011 Dec 9.
- British National Formulary (BNF); NICE Evidence Services (UK access only)
- CEU Clinical Guidance: Emergency Contraception; Faculty of Sexual and Reproductive Healthcare (March 2017 - updated July 2023)
- Drug interactions with hormonal contraception; Faculty of Sexual and Reproductive Healthcare (January 2017 - last reviewed 2019)
- Shen J, Che Y, Showell E, et al; Interventions for emergency contraception. Cochrane Database Syst Rev. 2017 Aug 2;8:CD001324. doi: 10.1002/14651858.CD001324.pub5.
Article history
The information on this page is written and peer reviewed by qualified clinicians.
Next review due: 30 Aug 2026
31 Aug 2021 | Latest version
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