---
title: "Contraceptive coil (IUD and IUS): Uses & Side Effects"
description: "Copper and hormonal coils compared, effectiveness, fitting, bleeding changes, pain relief and warning signs after insertion."
url: https://healthanswers.co.uk/treatments/contraceptive-coil/
robots: noindex
---

# Contraceptive coil (IUD and IUS): Uses & Side Effects

Treatments

Copper and hormonal coils compared, effectiveness, fitting, bleeding changes, pain relief and warning signs after insertion.

Written by HealthAnswers editorial team Medically reviewed by [HealthAnswers UK doctor review panel](https://healthanswers.co.uk/our-doctors/) Reviewed 1 August 2026

## Quick answer

What is the difference between a copper coil and a hormonal coil? A contraceptive coil is a small device placed in the womb. The copper IUD is hormone-free and can make periods heavier; the hormonal IUS often makes periods lighter. Both are over 99% effective, last for years and can be removed whenever pregnancy is wanted.

## Who is this page for?

This page is for people in the UK who want a plain-English overview of Contraceptive coil (IUD and IUS), including when to seek help and what NHS care usually involves. It explains general information, not what is wrong with you personally.

## Who should skip this page?

Skip this page if you need a diagnosis, a prescription, or emergency care. It cannot replace a GP, pharmacist, NHS 111 or 999. If you are in immediate danger, call 999; for urgent advice that is not life-threatening, call 111 in England, Scotland or Wales, or use your GP out-of-hours service in Northern Ireland.

On this page 3 sections

## Key facts about contraceptive coil

- The copper IUD can also be the most effective emergency contraception.
- Local anaesthetic and pain-relief options can be discussed before fitting.
- Check threads as advised and seek help if they feel different or cannot be found.

## Copper IUD

The copper device contains no hormone. Depending on the device it works for 5 or 10 years and can be used for emergency contraception within the appropriate window.

## Hormonal IUS

The IUS releases a small amount of progestogen in the womb and lasts for several years depending on the product. Some types also treat heavy periods or provide the progestogen component of HRT.

## Fitting and follow-up

A trained clinician inserts the device through the cervix. Cramping and light bleeding are common afterwards. Follow the service’s advice about contraception cover, thread checks and review.

## ! Important safety information for contraceptive coil

Contact the fitting service urgently for severe or worsening lower-abdominal pain, fever, smelly discharge, very heavy bleeding, pregnancy symptoms, or threads that suddenly feel different. Call 999 for severe pain with fainting, collapse or serious illness.

## Common questions about contraceptive coil

How painful is coil fitting? Experience varies from mild cramping to significant pain. Ask the service beforehand about pain relief, local anaesthetic and stopping if needed. Will a coil change my periods? Copper coils can make periods heavier or more painful. Hormonal coils often cause irregular bleeding initially and usually make periods lighter over time. How quickly does fertility return? Fertility can return immediately after removal, although pregnancy timing varies naturally.

## Sources

- [NHS — Methods of contraception](https://www.nhs.uk/contraception/methods-of-contraception/)