Hormonal coil at Nuffield Health at St Bartholomew's Hospital

It is placed inside your uterus and releases progesterone – the same hormone found in contraceptive pills. A hormonal coil can also be used to treat heavy periods.

How does a hormonal coil work?

The coil is a small, plastic T-shaped device. It slowly releases progesterone; not only preventing pregnancy but also making your periods lighter and less painful by:

• Thickening  the mucus in your cervix preventing sperm from traveling to fertilise an egg
• Making the lining of your uterus (endometrium) thinner preventing an egg from implanting
• Preventing ovulation (in some women)

What happens during hormonal coil fitting?

Hormonal coil fitting takes between 15 and 20 minutes. It is usually fit within 7 days after the start of your period. 

A nurse or gynaecologist will check to make sure you are not pregnant, that you do not have any existing infection in your womb and the size and position of your womb. 

The device is inserted through your cervix into your womb. Two fine threads attached to the bottom of the coil will remain at the top to your vagina. The threads allow you and your gynaecologist to check the device is in place. 

Coil fitting can be uncomfortable however most women do not experience any pain.

After hormonal coil fitting

You may feel cramping similar to period pain just after your fitting. Take over the counter pain killers such as paracetamol to ease this symptom. It is not unusual to experience light vaginal bleeding for a few days. 

Your consultant or nurse will probably want to see you for a follow-up after your first period. You can continue to wear your hormonal coil for five years. It will need to be replaced or removed by a trained professional. 

Most women experience no symptom following hormonal coil fitting. You should contact your consultant or nurse if you experience:

• Continued abdominal pain following fitting
• Unusual vaginal discharge
• If you think your coil has dislodged (fallen out)