Of course, it also lowers sex drive[1], while causing weight gain, cancer[3], and heart problems[4].
For historical reasons IUDs are uncommon in the US. This is unfortunate. They aren't perfect, but they are relatively cheap, extremely reliable, and remarkably safe. Depending on the type, they also have few or no side effects. Worth considering...
[1]: This one arguably isn't a health benefit, but in many ways it's huge. With a few exceptions, humans are sexual beings, and frequency of sexual encounters correlates highly to a range of positive health outcomes, happiness, avoidance of depression, and strong long-lasting relationships.
[2]: This one confuses people, because it also prevents cancer. Best evidence is that it has a fairly strong protective effect on ovarian cancer, but causes breast and cervical cancer. The net effect on total cancer rates is still unknown; it's certainly not a clear cut benefit though, and it may be a clear net negative. (As always, these sort of epidemiology numbers are a real headache to parse. Comparing a big effect on a rare event to a small effect on a common event is very tricky. Still, anything that boosts breast cancer rates is kind of scary.)
[3]: This one is clearcut. Hormone based birth control causes a range of heart issues, from heart attacks via clots, to cardiovascular diease. We're still trying to figure out how big this factor is, but it's already clear that if you have any risk factors (ie, you're overweight, or have a family history of heart disease) you should NOT be on combined oral contraceptives, and any hormone based birth control is very iffy.