Kyleena (levonorgestrel-releasing intrauterine system) is a brand-name intrauterine device (IUD) that’s used to help prevent pregnancy. Kyleena isn’t known to interact with other medications. But ...

There are five types of IUDs available in the US — each with different hormones, side effects, and effectiveness.

It takes one week for oral birth control to work or to start working again if you missed two pills. Copper IUDS work up to five days retroactively.