What Is an IUD?
An intrauterine device (IUD) is a long-acting reversible contraceptive (LARC) that is placed inside the uterus to prevent pregnancy. It is a small, T-shaped device made of plastic and copper or containing hormones.
There are two types of IUDs:
Copper IUD (non-hormonal) – Releases copper, which prevents sperm from fertilising an egg.
Hormonal IUD (Mirena, Kyleena, etc.) – Releases progestogen, which thickens cervical mucus and may stop ovulation.
An IUD is inserted by a healthcare professional and can last between 5 and 10 years, depending on the type. It is one of the most effective and low-maintenance contraception options available.
Who is an IUD suitable for?
An IUD may be a good choice if you:
- Want long-term, highly effective contraception (over 99% effective).
- Prefer a low-maintenance method that doesn’t require daily or weekly attention.
- Are unable to use oestrogen-based contraception (e.g. the pill or patch).
- Have heavy or painful periods (hormonal IUDs can make them lighter or stop them).
However, it may not be suitable if you:
- Have certain uterine conditions (such as fibroids) that affect IUD placement.
- Are prone to pelvic infections or have a history of pelvic inflammatory disease (PID).
- Have an untreated sexually transmitted infection (STI) at the time of insertion.
How does it work, and what are the options?
The copper IUD works by releasing copper, which:
- Stops sperm from surviving in the uterus or fallopian tubes.
- Prevents implantation of a fertilised egg.
The hormonal IUD releases progestogen, which:
- Thickens cervical mucus to block sperm.
- Thins the uterine lining, making implantation unlikely.
- May stop ovulation in some women.
The procedure involves:
- A GP or nurse inserts the IUD into the uterus using a small applicator.
- The procedure takes 5–10 minutes and can cause mild discomfort.
- Once fitted, the IUD can stay in place for 5–10 years, depending on the type.
Other contraceptive options include the Combination Pill, Mini Pill, Contraceptive Patch or Contraceptive Ring.
