There are two kinds of IUDs available in the U.S.—with hormones and without. Both the Mirena and Skyla IUDs release a small amount of the synthetic hormone progestin to help your body keep sperm from reaching your cervix. Mirena lasts up to 5 years; Skyla is slightly smaller than Mirena and lasts up to 3 years.

The Paragard IUD is hormone-free and doesn’t alter your periods. It’s made of plastic and a small amount of natural, safe copper and can work for up to 12 years.