Mirena is the most reviewed brand of hormonal coil or 'IUS' at The Lowdown. Like all hormonal coils it releases a low amount of progestogen into your womb, meaning low levels circulate through your system - this may be why most women experience few side effects. Plus many users have lighter bleeds or even no periods. Once it's fitted, the Mirena can stay in for up to 5 years.
The Mirena coil can be fitted by a doctor or nurse, usually at a GP practice or sexual health clinic. During the fitting, the doctor or nurse will use a speculum (similar to when you have a smear test) to open up your vagina and insert the coil through the cervix into the womb. This may be a little uncomfortable and you should be offered pain relief. Find out more about what to expect in our guide to coil fittings .
Does the Mirena coil make you gain weight?
There is no evidence the hormonal coil can affect weight. Make sure to take a look at our users' reviews to see how our community report the IUS affects their weight. You can also find out more in our guide to contraception and weight .
Does the hormonal coil affect acne?
It's uncertain as to whether or not the hormonal coil can affect acne. According to our user reviews, some women find their acne is worse after having a hormonal coil inserted. However the levels of progestogen are much less than that found in the contraceptive pill, therefore the impact may be less noticeable. Take a look at our user reviews section or head to our guide on acne and the pill to find out more.
Is sore breasts a side effect of the Mirena coil?
Some women experience sore breasts on the Mirena coil. There's a lack of research to confirm how common this tenderness or pain is, but it is a recognised side effect of the hormone progestogen released by the coil - and is often a side effect that comes up in our user reviews at The Lowdown. If this doesn't settle in a few months, or you notice any new symptoms such as a breast lump or nipple discharge, please make sure you see your doctor.
Can the Mirena coil impact my mood?
Hormonal methods of contraception may affect your mood. However there are several factors that influence this such as your age, medical history and contraceptive history, as well as what else may be going on in your life. Most women report no mood changes with their contraception. Some women report an improvement in mood changes or mood swings throughout their cycle (associated with premenstrual syndrome (PMS)). Make sure to check out our users' reviews to see how our community report the IUS impacts their emotions. You can also find out more about this complex topic in our guide to contraception and mood .
How long does it take for Mirena to stop periods?
After 12 months of using the Mirena coil, most women have infrequent or no bleeding at all and after 3 years, 1 in 4 women won't have any periods. However, some women may also continue to have spotting or light irregular bleeding long term. If your bleeding pattern changes or your periods suddenly stop, check your coil threads and consider doing a pregnancy test. Checkout how women who have left a review for Mirena at The Lowdown report changes to their periods in the side effects section.
How the Mirena coil works:
Mirena is a small, T-shaped plastic device that is inserted into your womb by a doctor or nurse. It releases the hormone progestogen gradually into your womb which prevents pregnancy by making the fluid in your cervix thicker (which makes it more difficult for sperm to enter the womb), and preventing the lining of your womb thickening enough for a fertilised egg to implant in it. Sometimes it can also stop you ovulating.
How to use the Mirena coil:
You need to go to a GP surgery or sexual health clinic where some staff are trained to fit coils. Find out more about coil fittings .
Once the Mirena coil is fitted, the only requirement is that you check you can feel your threads which hang down through the neck of the womb in the top of the vagina. You should do this regularly, every few weeks, to make sure that your coil is in place. Read how to do this here
If your coil is fitted in the first 7 days of your cycle, you’ll be protected against pregnancy immediately. If it’s fitted at any other time, you'll need to use condoms or other contraception for 7 days afterwards. You can read our comprehensive guide on how the hormonal coil works here .
To maintain its contraceptive effect Mirena needs to be replaced every 5 years. Your hormonal coil can be removed at any time by a trained doctor or nurse. It’s normally simpler than having it fitted – they will gently pull on the threads and the T shape folds up and it can be pulled out of the womb.
How safe is the Mirena coil:
On the whole, the Mirena coil is very safe. However, there’s a small risk that on insertion the coil may go through the wall of the womb and ‘perforate’ it. If this happens, then you may need surgery to remove it but this is rare. Following the coil insertion, there is also a slight risk of infection which may lead to pelvic inflammatory disease. If you have unusual or smelly discharge, abdominal or pelvic pain, a high temperature or chills, you should contact your doctor.
In the rare circumstance you become pregnant whilst using the coil there’s a small increased risk of ectopic pregnancy – when the egg implants outside the womb, normally the fallopian tubes. However, the overall risk of ectopic pregnancy is less in women using a coil than in women using no contraception at all.
It's important to remember that it does not protect you from STIs.;