Three IUS containing levonorgestrel are currently available in the UK. Because of the differences in indications, durations of use, and insertion techniques of these products, they should always be prescribed by brand name.
IUS containing 52mg levonorgestrel
Mirena is licensed for 5 years of contraceptive use, whereas Levosert is licensed for 3 years' use
Mirena is licensed for 4 years' use for endometrial protection as part of an HRT regimen (Levosert is not licensed for this indication)
The two IUS have different insertion techniques; Levosert requires a two-handed technique
The Mirena introducer has a diameter of 4.4mm, compared with 4.8mm for the Levosert introducer.
The release rates and serum levels of levonorgestrel provided by Mirena and Levosert are similar: initially 20 microgram daily, falling to 12 microgram daily after 3 years.
IUS containing 13.5mg levonorgestrel
Jaydess is a smaller, lower-strength version of Mirena that contains 13.5mg levonorgestrel. It is licensed for 3 years' use for contraception only.