Playin' It Safe

Intra-Uterine System

What is an Intra-Uterine System?

An Intra-Uterine System (IUS) is small, plastic device containing the hormone progestrogen, which is put into the womb. It stops the sperm meeting an egg or stops a fertilised egg cell settling in the uterus. A nurse or doctor will fit it. Women are taught to check the IUS by feeling the threads high in the vagina. The IUS is over 99% effective.

What are the advantages?

  • It works as soon as inserted
  • There is no need to think about contraception for as long as the IUS works
  • It works for 5 years, but can be removed at any time
  • Periods can be lighter and shorter

What are the disadvantages?

  • Irregular light bleeding is common during the first 3 months
  • There may be some temporary side effects such as breast tenderness or acne
  • It does not protect against STIs