The emergency contraceptive pill, also known as the morning-after pill or post-coital pill, can be used by a woman to reduce the risk of pregnancy after having unprotected sex.
It can also be used if another method of contraception has failed, for example if a condom splits or you have forgotten to take one of your contraceptive pills.
It does not protect you against pregnancy during the rest of your menstrual cycle and is not intended to be a regular form of contraception. Using the emergency contraceptive pill repeatedly can severely disrupt your natural menstrual cycle.
The emergency contraceptive pill does not protect against sexually transmitted infections.
Types of emergency contraceptive pill
- Levonelle - can be taken up to three days (72 hours) after unprotected sex and is available free of charge on prescription or can be bought from your local pharmacy if you are over 16. Levonelle can be taken more than once in a menstrual cycle. It does not interfere with your regular method of contraception.
- ellaOne - a newer type of emergency contraceptive pill that can be taken up to five days (120 hours) after having unprotected sex. It is only available on prescription. It is thought to be more effective than Levonelle, but may prevent other types of hormonal contraception from working for a week after use, and is not recommended for use more than once per menstrual cycle.
Who can use it
Most women can use the emergency contraceptive pill. This includes women who are breastfeeding and women who cannot usually use hormonal contraception, such as the combined pill and contraceptive patch.
The World Health Organization does not identify any medical condition that limits the use of Levonelle. The safety of ellaOne has not been so widely evaluated yet.
Read more about who can use Levonelle and ellaOne.
How the emergency contraceptive pill works
Both Levonelle and ellaOne work mainly by affecting ovulation (the release of an egg from the ovaries). ellaOne works closer to ovulation, when the risk of pregnancy is highest.
Levonelle is not effective after fertilisation, and it is not yet clear whether ellaOne has any effect after ovulation.
Interactions and side effects
Taking the emergency contraceptive pill has not been shown to cause any serious or long-term health problems. However, it can sometimes have side effects, such as tummy pain and irregular menstrual bleeding.
Other emergency contraception
The copper intrauterine device (IUD) is a small, T-shaped contraceptive device made from plastic and copper that fits inside the womb.
The IUD can be used as a method of emergency contraception up to five days after unprotected sex or up to five days after the earliest time you could have released an egg (ovulation).
Read more about the intrauterine device.
Most women can use the emergency contraceptive pill. This includes women who cannot usually use hormonal contraception, such as the combined pill and contraceptive patch.
The World Health Organization does not identify any medical condition that limits the use of Levonelle.
The safety of ellaOne has not yet been widely evaluated, so the manufacturer advises avoidance if you are allergic to it or have severe liver problems. It also advises caution in women who:
- have asthma that is not properly controlled on steroids
- have heriditary problems with lactose metabolism
Speak to your doctor if you are concerned any of the above apply to you.
Pregnanct and breastfeeding women
There is no evidence that the emergency contraceptive pill harms a developing baby.
Levonelle can be taken when breastfeeding. Although small amounts of the hormones contained in the pill may pass into your breast milk, it is not thought to be harmful to your baby.
The safety of ellaOne during breastfeeding is not yet known, so the manufacturer does not recommend breastfeeding for up to 36 hours after taking this pill.
If you are already taking the contraceptive pill
If you needed to take the emergency contraceptive pill because you forgot to take some of your regular contraceptive pills or did not use your patch or vaginal ring correctly, you should take your next contraceptive pill, insert a new ring or apply a new patch within 12 hours of taking the emergency contraceptive pill.
You should then continue taking your regular contraceptive pill as normal.
If you have taken Levonelle, you will need to use additional contraception, such as condoms, for:
- the next 7 days if you use the patch, ring or combined pill
- the next 2 days if you use the progestogen-only pill
If you have taken ellaOne, you will need to use additional contraception, such as condoms, for:
- the next 14 days if you use the patch, ring or combined pill
- the next 9 days if you use the progestogen-only pill
The emergency contraceptive pill may interact with other medicines.
- the complementary medicine St John’s Wort
- some medicines used to treat epilepsy
- some medicines used to treat HIV
- some medicines used to treat tuberculosis
- medication such as omeprazole to make your stomach less acidic
EllaOne cannot be used if you are already taking one of these medicines as it will not be effective. Levonelle may still be used, but the dose will need to be increased - your doctor or pharmacist will be able to advise on this.
It's worth remembering that an emergency IUD is more effective than the emergency contraceptive pill, and will not react with any other medication.
There should be no interaction between the emergency contraceptive pill and most antibiotics.
It is fine to take the emergency contraceptive pill if you are already taking a combined oral contraceptive pill or progestogen-only pill.
If you want to check that your medicines are safe to take with the emergency contraceptive pill, ask your doctor or a pharmacist. You should also read the patient information leaflet that comes with your medicines.
Taking the emergency contraceptive pill has not been shown to cause any serious or long-term health problems. However, it can sometimes have side effects.
Common side effects include:
- abdominal (tummy) pain
- irregular menstrual bleeding (spotting or heavy bleeding) before your next period is due
- nausea (feeling sick)
Less common side effects include:
- breast tenderness
- vomiting - seek medical advice if you vomit within three hours of taking the emergency contraceptive pill
Any side effects will normally pass quickly. If you vomit within 3 hours of taking ellaOne or 2 hours of taking Levonelle, you will need to take a repeat dose or have an IUD fitted.
When to see a doctor or nurse
If you are concerned about any symptoms after taking the emergency contraceptive pill, contact your doctor or speak to a nurse at a sexual health clinic.
You should talk to a doctor or nurse if:
- you think you might be pregnant
- your next period is more than seven days late
- your period is shorter or lighter than usual
- you have any sudden or unusual pain in your lower abdomen (tummy)