There are two types of IUDs: copper and hormonal. They look like little capital T’s with strings attached to the bottom. The top bar of the T rests in the uterus and the bottom bar rests in the cervix (tube connecting the uterus to the vagina). Both are very successful at preventing pregnancy but they do not impact STI spread, so barrier methods and/or regular testing are recommended.

The copper IUD is popular worldwide as a low-maintenance form of contraception. Because it’s essentially a piece of metal, it can stay in place for 10+ years and not diminish in efficacy.

There are many forms of hormonal IUDs, including a smaller version that is specifically intended for those who have never had a baby. (When delivering a baby, the tube leading to the uterus—the cervix—widens. For this reason, in those who have had a baby, it’s much easier to insert an IUD. The smaller IUD is easier to insert if the cervix has never opened/dilated.)

The main hormone in hormonal IUDs is progestin (same hormone that’s in the progestin-only pill, Depo and the implant). However, unlike these other forms of birth control, the progestin in IUDs does not generally spread to the bloodstream but instead stays in the local and surrounding uterine tissue. This means it’s a good option for those who are hesitant to use other forms of hormonal birth control that can impact many systems of the body. 

Because IUDs act “locally,” they oftentimes have no impact on menstruation, which can make them a good option for those who like to keep a period. However, it’s important to know that copper IUDs are often associated with heavier periods and more cramping, so don’t use if you already have bad period symptoms. 

Both types of IUD can be used as emergency contraception after unprotected sex. They are VERY effective when used in this manner but the hurdle is that they need to be inserted by a trained medical professional.

Lots of folks worry that their partner might be able to feel it. Really, they shouldn’t. The only thing you or your partner might feel is the strings that attach to the end of the cervical portion. That will also help you check to make sure it’s in place. 

Finally, there are risks associated with IUDs. Though the risks are small, you should still be aware that there is a risk of uterine perforation (poking a hole in the uterus), infection and spontaneous expulsion (the IUD falling out).