Overview

The levonorgestrel (LNg) intrauterine device (IUD) releases small amounts of levonorgestrel, a form of progesterone, into the uterus each day. This type of IUD reduces cramping and heavy menstrual bleeding. And it is a highly effective method of birth control.

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.

• Breast tenderness
• Mood swings
• Headaches
• Acne

These side effects are not common. But if they do happen, they usually go away after the first few months.