Over 99% effective.
Less than one woman in 100 will get pregnant over its 5 year duration of use.
How it works
A small plastic T-shaped device, which releases the hormone progestogen, is placed in the womb and prevents the sperm reaching an egg. It also prevents an egg settling in the womb (implantation).
Possible Side Effects
- May have irregular bleeding and some pain in first few weeks / months
- May fall out
- Partner may feel threads during intercourse
- Breast tenderness, acne, headaches in first few months
- Ectopic pregnancy if IUS fails
Possible risks at time of insertion
- There is a very small risk of perforating the womb
Advantages / Benefits
- Lasts five years
- No need to remember contraception
- Fertility returns immediately once removed
- Periods lighter and shorter
- Not suitable for those with current pelvic infection or untreated sexually transmitted diseases
- May be more difficult to insert in young people without children
- Very suitable for women with heavy, painful periods
- Good alternative to sterilisation
Who can provide it?
IUS provider list. (PDF 40Kb)
If you are less than 25, have a new sexual partner or more than one sexual partner in the last year then you will require screening for chlamydia before insertion.
It is usually put in during Day 1-7 of menstrual cycle (day 1 = first day of bleeding).
Women are taught to feel threads in vagina.
May be used as part of HRT.