Hormonal coil (IUS)

Hormonal coil ius

Benefits

  • Works for three or five years
  • You don’t have to prepare for or interrupt sex
  • You don’t have to remember to take a pill everyday
  • If you have heavy or painful periods, the IUS can make your periods lighter, shorter, and sometimes less painful – they may stop completely
  • Fertility will return to normal when the IUS is removed
  • The IUS is not affected by other medicines.

The hormonal coil, also known as the IUS (intrauterine system) is a small T-shaped plastic device that sits in your womb and releases the progestogen hormone. It is long-acting and reversible, so you can take it out if you want to get pregnant.

It is the sixth most popular method of contraception in the UK, and is becoming more popular, particularly amongst women over 25.

Hormonal coil ius effectiveness
Hormonal coil ius lasts for
Hormonal coil ius period cycle
Hormonal coil ius side effects

How it works

How to use it

Hormonal coil ius how

A clinician will insert the small, T-shaped plastic device into your womb (uterus).

Once the IUS is in place, you don't have to think about contraception. It won't interrupt sex and your partner should not be able to feel it. There are two brands of IUS hormonal coil available in the UK - the Mirena coil lasts for five years, and the Jaydess coil for three years.

It can be removed at any time by a trained doctor or nurse, but you must use condoms as well or abstain from sex for 7 days prior to removal.

Why it works

Hormonal coil ius why

The IUS releases a progestogen hormone which prevents pregnancy by:

  • Thickening the mucus in the neck of the womb, so it is harder for sperm to penetrate the womb and reach an egg
  • Thinning the lining of the womb, so there is less chance of a fertilised egg implanting into the womb
  • In some women, the IUS also stops the ovaries from releasing an egg (ovulation), but most women will continue to ovulate.
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Things to consider

What if?

The IUS doesn’t stay in place:

An IUS has two thin threads that hang down a little way from your womb into the top of your vagina. You will be taught how to feel for the threads and check the IUS is still in place. If you can't feel the threads or if you think the IUS has moved, you may not be fully protected against pregnancy. See your doctor or nurse straight away and use extra contraception, such as condoms, until your IUS has been checked.

It’s highly unlikely that your IUS will come out.

Suitability

Most women can use an IUS, but your clinician will ask about your family and medical history to find out whether it’s right for you.

The IUS is suitable for women who can’t take the hormone oestrogen (which is in the combined pill).

IUS may not be suitable for you if you have or have had certain health conditions.

Side effects & risks

Common Rare
Short term:

Irregular bleeding and spotting in the first six months. This is not harmful and usually decreases with time.

Some women experience headaches, acne and breast tenderness after having the IUS fitted.

Pelvic infections may occur in the first 20 days after the IUS has been inserted. Fewer than 1 in 100 women will get an infection.

Long term:

Minor changes in mood and libido.

Irregular vaginal bleeding and pain.

Small fluid-filled cysts on the ovaries – these usually disappear without treatment.

Questions?

Before you have an IUS fitted, you will have an internal examination to determine the size and position of your womb. This is to make sure that the IUS can be positioned in the correct place.

You may also be tested for any existing infections, such as STIs, so that any infections can be treated beforehand.

The IUS can be fitted at any time during your monthly menstrual cycle, as long as you're definitely not pregnant.

It takes about 10 minutes. Some women find the procedure painful or uncomfortable. The vagina is then held open (like during a cervical screening / smear test), and the IUS is inserted through the cervix and into the womb.

If it is fitted in the first five days of your menstrual cycle you will be immediately protected against pregnancy. If it is fitted at any other time, you will need to use additional contraception for the first 7 days.

The non-hormonal coil IUD releases copper that kills eggs and sperm.

The hormonal coil IUS releases a progestogen hormone, which thickens the mucus from the cervix (opening of the womb), making it harder for sperm to move through it and reach an egg. It also causes the womb lining to become thinner and less likely to accept a fertilised egg. In some women, the IUS also stops the ovaries from releasing an egg (ovulation), but most women will continue to ovulate.

Your partner shouldn't be able to feel your IUS during sex. If he can feel the threads, get your GP or clinician to check your IUS is in place. They may be able to cut the threads a little.

There is a very small risk of infection. If you have any of the following symptoms within a few days of having an IUS fitted, you should see your GP (or clinician who fitted the IUS) straight away:

  • Have pain in your lower abdomen
  • Have a high temperature
  • Have a smelly discharge.

Fertility will return to normal when the IUS is removed.

If you decide to have your IUS taken out, but you don’t want to get pregnant, you will need to use condoms for 7 days before you have it removed. This is because sperm can live for up to 7 days inside the body.

There's no evidence that an IUS will affect your weight.

The GP or clinician that fits your IUS will teach you how to feel for the threads and check that the IUS is still in place. If you can't feel the threads or if you think the IUS has moved, you may not be fully protected against pregnancy. See your doctor or nurse straight away and use extra contraception, such as condoms, until your IUS has been checked.

The IUS is inserted through the cervix and into the womb. This procedure can be painful or uncomfortable for some women but only takes a few minutes. Some women also experience cramps for a short time afterwards.

There's no evidence that having an IUS fitted will increase the risk of cervical cancer, cancer of the uterus or ovarian cancer.

In fewer than 1 in 1,000 cases, an IUS can make a tiny hole in the womb or neck of the womb (cervix) when put in. The risk of perforation is extremely low. Contact your GP straight away if you feel a lot of pain in the lower abdomen after having an IUS fitted. If there is a suspected perforation, go to A&E to see a specialist. If perforation occurs, you may need surgery to remove the IUS.

Occasionally, the IUS can be rejected by the womb. This is uncommon and is more likely to happen soon after it has been fitted rather than later on.

If you get an STI while you have an IUS fitted, it could lead to pelvic infection. STIs and pelvic infections need to be treated as soon as possible. An IUS doesn't protect you against STIs, so you may also have to use condoms when having sex.

Although this is unlikely, if the IUS fails and you become pregnant, you should have it removed as soon as possible if you are continuing with the pregnancy. You should also have a scan to ensure the pregnancy is not ectopic.

Yes, you can fit the IUS more than 28 days post-delivery.

An IUS can be used safely while you are breastfeeding and will not affect your milk supply.

Most women can use an IUS, but your GP or clinician will ask about your family and medical history to find out whether it’s right for you.

The IUS is suitable for women who can’t take the hormone oestrogen (which is in the combined contraceptive pill).

IUS may not be suitable for you if you have or have had certain health conditions.

  • Breast cancer or have had it in the past five years
  • Cervical cancer
  • Liver disease
  • Heart disease
  • Problems with your womb or cervix or unexplained vaginal bleeding between periods or after sex
  • An untreated STI or pelvic infection.

If you're 45 or older when you have the IUS fitted, it can be left until you reach menopause or you no longer need contraception. The IUS can also be used for HRT.

Yes, whilst using the IUS you can use tampons and/or towels.

Where can I get it?

The IUS is free on the NHS. It can be fitted by most sexual health clinics and some GPs. Talk to your clinician about whether it’s right for you. Your clinician will be able to tell you where you can get it fitted nearby, if they can’t do it themselves.

The IUS can be fitted at any time during your monthly menstrual cycle, as long as you're definitely not pregnant.