Mirena is an intrauterine system (IUS) used to prevent pregnancy for up to 5 years. Mirena works by slowly releasing levonorgestrel into the uterus at a rate of approx. 20 micrograms per day. Levonorgestrel prevents pregnancy and decreases abnormally heavy menstrual blood loss.
Kyleena is an intrauterine system (IUS) used to prevent pregnancy for up to 5 years. Kyleena contains 19.5mg of levonorgestrel. Kyleena may prevent pregnancy in several ways: thickening the mucus in the cervix (this makes it harder for sperm to pass through the cervix) and reducing the monthly thickening of the lining of the uterus.
Copper intrauterine devices can be effective for up to 10 years and are made of copper or plastic. The copper interferes with both sperm and eggs and prevents fertilized eggs from attaching to the uterus.