What you need to know about the hormonal coil

The coil is a small T-shaped piece of plastic that sits inside the uterus. Getting it fitted can be painful, but the process only takes 5-10 minutes. 

It works by releasing small amounts of the hormone progestogen. It’s the most effective contraceptive, more effective than sterilisation. There’s a simple procedure to remove it and then your fertility returns to what is normal for you.

Also known as

  • the coil

  • the hormone coil


  • IUD

  • intrauterine system

  • IUS

  • Mirena

  • Levosert

  • Jaydess

  • Kyleena

Our team says

Many people love this method – no periods, no action required after the fitting. The drawbacks are irregular bleeding in the first 6 months, and the fitting process – which is manageable, but does need an appointment and procedure and possibly an evening’s rest with a hot water bottle.

Dr Paula Baraitser. Medical Director, SH:24

Likelihood of getting pregnant over 1 year

The hormonal coil is over 99% effective. This means fewer than 1 person in 100 using the coil will get pregnant in one year.

The hormonal coil is a good option if you...

  • have heavy periods or don’t want a period

  • don’t mind having some irregular bleeding 

  • don’t want to have to remember to do something every day (like taking a pill)

  • would rather have less artificial hormones in your bloodstream

  • suffer from endometriosis, as less bleeding means less pain

  • have polycystic ovary syndrome, as it can reduce the risk of endometrial cancer

It’s not recommended for people who:

  • have irregular bleeding before the coil is fitted, unless you’ve investigated the causes (once the coil is fitted, it’s difficult to work out if irregular bleeding is caused by the coil or something else like an infection)

  • have an unusual sized or shaped womb, for example, if you have large fibroids – you may still be able to have your coil fitted but you may need an ultrasound scan at the same time

  • have untreated STIs (sexually transmitted infections) but you can have a coil fitted once they’re treated

  • want to have a regular period

The hormonal coil is the most effective form of contraception

It's one of the most effective ways to prevent pregnancy, even more effective than sterilisation.

After the coil is inserted, depending on what type you get, it lasts between 3 and 8 years. This means you don’t need to remember to do anything with it daily, or when you’re having sex.

Getting the coil fitted and removed

Some people find getting the coil painful. Others don’t. It’s usually a short procedure, which takes less than 10 mins and requires an internal examination. It’s a good idea to prepare for your appointment and take it easy afterwards.

You can have your coil removed at any time and it only takes 2–3 minutes.

To prevent pregnancy, you need to use condoms or not have sex for 7 days before it’s removed. This is because one of the effects of the coil is to stop a fertilised egg from implanting in the womb. If you remove the coil and the egg is travelling towards the womb (which can take up to 7 days) then the coil is there to stop it from implanting.

There are some side effects

Most of the effects of the hormone coil take place in the womb and cervix, and you’re less likely to experience side effects in other parts of your body.

But some of the hormones do enter your bloodstream. Sometimes, people get acne, feel bloated and have mood changes when using an IUS.

Did you know?

You can use tampons with your coil in place. Many people also use menstrual cups with their IUS. There’s no evidence that this will dislodge your coil, but do take care to break the suction with your finger before removing your cup.

Everything you wanted to know about sexual health and wellbeing - your questions answered by our expert team.