Emergency contraception can prevent pregnancy after unprotected sex or if your contraceptive method has failed – for example, a condom has split or you've missed a pill. There are two types:
- the emergency contraceptive pill (sometimes called the morning after pill)
- the IUD (intrauterine device, or coil)
There are two kinds of emergency contraceptive pill.
- Levonelle has to be taken within 72 hours (three days) of sex, and
- ellaOne has to be taken within 120 hours (five days) of sex. Both pills work by preventing or delaying ovulation (release of an egg).
The IUD can be inserted into your uterus up to five days after unprotected sex, or up to five days after the earliest time you could have ovulated. It may stop an egg from being fertilised or implanting in your womb.
Emergency contraception does not protect against sexually transmitted infections (STIs).
How Levonelle Works
Levonelle contains levonorgestrel, a synthetic version of the natural hormone progesterone. In a woman’s body, progesterone plays a role in ovulation and preparing the uterus for accepting a fertilised egg.
It’s not known exactly how Levonelle works, but it’s thought to work primarily by preventing or delaying ovulation. You can take Levonelle more than once in a menstrual cycle. It does not interfere with your regular method of contraception.
How ellaOne Works
ellaOne contains ulipristal acetate, which means that it stops progesterone working normally. It prevents pregnancy mainly by preventing or delaying ovulation. ellaOne may prevent other types of hormonal contraception from working for a week after use, and it’s not recommended for use more than once in a menstrual cycle.
ellaOne used to be available only on prescription, but it is now available to buy in pharmacies.
Levonelle and ellaOne do not protect you against pregnancy during the rest of your menstrual cycle and are not intended to be a regular form of contraception. Using the emergency contraceptive pill repeatedly can disrupt your natural menstrual cycle.
How the IUD works
The intrauterine device (IUD) is a small, T-shaped contraceptive device made from plastic and copper. It’s inserted into the uterus by a trained health professional. It may prevent an egg from implanting in your womb or being fertilised.
If you’ve had unprotected sex, the IUD can be inserted up to five days afterwards, to prevent pregnancy. It’s more effective at preventing pregnancy than the emergency pill, and it does not interact with any other medication.
You can also choose to have the IUD left in as an ongoing method of contraception.
At a glance: facts about emergency contraception
- Both types of emergency contraception are effective at preventing pregnancy if they are used soon after unprotected sex. Less than 1% of women who use the IUD get pregnant, whereas pregnancies after the emergency contraceptive pill are not as rare. It’s thought that ellaOne is more effective than Levonelle.
- The sooner you take Levonelle or ellaOne, the more effective it will be.
- Levonelle or ellaOne can make you feel sick, dizzy or tired, or give you a headache, tender breasts or abdominal pain.
- Levonelle or ellaOne can make your period earlier or later than usual.
- If you’re sick (vomit) within two hours of taking Levonelle, or three hours of taking ellaOne, seek medical advice as you will need to take another dose or have an IUD fitted.
- If you use the IUD as emergency contraception, it can be left in as your regular contraceptive method.
- If you use the IUD as a regular method of contraception, it can make your periods longer, heavier or more painful.
- You may feel some discomfort when the IUD is put in – painkillers can help to relieve this.
- There are no serious side effects of using emergency contraception.
- Emergency contraception does not cause an abortion.
What are the side effects of using the emergency pill?
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
- feeling sick
Less common side effects include:
- breast tenderness
- vomiting (seek medical advice if you vomit within two hours of taking Levonelle, or three hours of taking ellaOne, as you will need to take another dose or have an IUD fitted)
If you are concerned about any symptoms after taking the emergency contraceptive pill, contact your GP 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 (this could be a sign of an ectopic pregnancy, where a fertilised egg implants outside the womb – this is rare but serious, and needs immediate medical attention)
What are the side effects of the IUD
Complications after having an IUD fitted are rare, but can include pain, infection, damage to the womb or expulsion (the IUD coming out of your womb). If you use the IUD as an ongoing method of regular contraception, it may make your periods longer, heavier or more painful.