Hormonal IUDs prevent pregnancy for 3 to 5 years, depending on which IUD is used.
How well does it work?
Most women have a significant decrease in uterine blood loss
with the LNg IUD. Some studies report up to a 95% reduction in blood loss.footnote 1 Increased spotting during the first couple
of months is common, followed by less bleeding thereafter.
What are common side effects?
The LNg IUD can reduce menstrual bleeding and cramps and, in many women, eventually cause menstrual periods to stop altogether. In this case, not menstruating is not harmful.
The LNg IUD may cause hormonal side effects similar to those caused by oral contraceptives.
These side effects are not common. But if they do happen, they usually go away after the first few months.
Fritz MA, Speroff L (2011). Abnormal uterine bleeding. In Clinical Gynecologic Endocrinology and Infertility, 8th ed., pp. 591-620. Philadelphia: Lippincott Williams and Wilkins.