An IUS is a small T-shaped plastic device that is put into your uterus (womb) and releases a progestogen hormone. This is similar to the natural progesterone that women produce in their ovaries.
The IUS has two threads at one end which hang through the opening at the entrance of your uterus (the cervix) into the top of your vagina.
There are two types of IUS – Jaydess and Mirena. In this information, the two different types are named where relevant. The general term IUS is used to refer to both types.
Jaydess is smaller than Mirena and has a lower dose of progestogen. It works for up to three years. Mirena works for up to five years.
If you are aged 45 or older when Mirena is fitted, it can be left in until the menopause.