According to the Liletta website, this IUD can remain in your uterus for up to six years, where it will release a hormone called levonorgestrel — a hormone found in many birth control pills. Mirena, on the other hand, can be used for up to seven years, per its website. Other than that extra year, though, there isn't a huge difference between the two brands, as Mirena also releases levonorgestrel. Both can result in lighter periods — or even safely stop them completely. Both Liletta and Mirena are also free of estrogen, which is ideal for breastfeeding parents as estrogen can lower your milk supply (via Healthline). 

Dr. Jessica Morse wrote for Bedsider Providers that, functionally, the two IUDs aren't that different. "Both are excellent at preventing pregnancy, and both are likely to cause noticeable decreases in menstrual bleeding or even complete cessation," she said.

Morse added that there is one consideration that may influence you choosing Liletta over Mirena, though.