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This page gives you information about the hormone coil recommended by your doctor.

What is a Mirena® intrauterine system?

This system is like many other types of coil. Mirena® will be fitted by a doctor and stay in the womb for a fixed period of time. It is much more effective than usual coils and has fewer side effects, making periods lighter.

Mirena® is made of a plastic, T-shaped frame which contains a low dose of hormone, also used in contraceptive pills but contains no oestrogen.

How effective is this contraception?

Mirena® is very effective compared to other forms of contraception. It acts in 2 ways; preventing sperm from getting through thicker mucus and making the lining of the womb extremely thin, stopping implantation.

In some women it can prevent egg release or ovulation.

If Mirena® does happen to fail, there is a higher risk of ectopic pregnancy. This is a pregnancy found outside the womb.

If you feel at any time that you may be pregnant, it is important to see your doctor to discuss your coil.

Fitting the Mirena®

The doctor will perform an internal examination to make sure there is nothing unusual before fitting the Mirena®. The coil is inserted either within a week of beginning your period, immediately after a termination or 6 weeks after having a baby.

Fitting the Mirena® is similar to having a smear test. A local anaesthetic may be used if needed. You will not be able to feel the Mirena® once fitted.

You will receive a follow appointment for about 6 weeks after the Mirena® is fitted.

Your partner should not be aware of the Mirena® during intercourse.

Removing or changing the Mirena®

Mirena® will last 5 years and if needed, a new one can be inserted at the same time the old one is removed. Removing the coil is only uncomfortable for a short time.

After the removal of the Mirena® your periods and fertility will return within a month.

Side effects

In the first months of use, there is a very small chance that the Mirena® may dislodge and come out. There may be bleeding, sometimes with pain.

There is a slight increase in progesterone levels which can cause headaches, water retention, breast tenderness or acne. This can also increase the chance of ovarian cysts.

After having the Mirena® fitted it can take from 3 to 6 months for the bleeding to settle down.

Contact information

If you have any questions, please contact your own consultant’s secretary.

Gloucestershire Domestic Abuse Support Service (GDASS)

This is a county-wide service offering a variety of support programmes for women and men over 16 years old who are experiencing domestic abuse.

Tel: 01452 726 570

Monday to Friday, 9:00am to 5:00pm

Domestic Violence Helpline

Tel: 0808 2000 247 (24 hours)

Email: support@gdass.org.uk

Website: www.gdass.org.uk

Further information

For further information, please visit the following website then search for Mirena® IUS:

Website: www.womens-health.co.uk

Printable version of this page

Mirena® intrauterine system GHPI0460_01_24 Department: Gynaecology Review due: January 2027 PDF, 277.8 KB, 3 pages
Reference number GHPI0460_01_24
Department Gynaecology
Review due January 2027