It is a hormonal intrauterine device (IUD) that's inserted into the uterus for long-term birth control (contraception). A T-shaped plastic frame that releases a type of progestin, IUD thickens the cervical mucus to prevent sperm from reaching or fertilizing an egg. IUD also thins the lining of the uterus and partially suppresses ovulation.
It is one of two hormonal IUDs with Food and Drug Administration approval. The other is Skyla, which prevents pregnancy for up to three years. IUD prevents pregnancy for up to five years after insertion.