The device is removed in a procedure similar to the insertion. All women who have a Mirena inserted will be contacted by phone at three and six months post insertion to ensure ongoing satisfaction with the device. Should you have any concerns at either of these contact times. Mirena (the intrauterine system or IUS) is placed in the uterus where it releases a hormone that affects the endometrium and provides contraceptive protection. In women of fertile age, Mirena is to be placed into the uterine cavity within seven days of the onset of menstruation. Mirena insertion instructions diagram. 11 Jan Mirena is a hormonal intrauterine device (IUD) that can provide long-term birth control (contraception). The device is a T-shaped plastic frame that's inserted into the uterus, where it releases a type of the hormone progestin. To prevent pregnancy, Mirena: Thickens mucus in the cervix to stop sperm from.