IUD stands for Intrauterine Device (basically: a device inside your uterus). It’s a small piece of flexible plastic shaped like a T. Sometimes it’s called an IUC — intrauterine contraception. Both copper IUDs and hormonal IUDs prevent pregnancy by changing the way sperm cells move so they can’t get to an egg. If sperm can’t make it to an egg, pregnancy can’t happen.

The ParaGard IUD uses copper to prevent pregnancy. Sperm doesn’t like copper, so the ParaGard IUD makes it almost impossible for sperm to get to that egg.