The IUD is a small, plastic device that is inserted by a physician / practitioner and left inside the uterus. Although there have been several types of IUDs, currently only two are available in the United States. Both are T-shaped and have a string at the base of the T that will extend trough the cervix and lie in the vaginal canal. The copper IUD releases a small amount of copper into the uterus and may remain in your body for up to 10 years. The hormonal IUD releases a small amount of the hormone progesterone into the uterus, but must be replaced every year.