do iud have estrogen
IUD Progesterone. An Intra-Uterine Device (IUD) is a small, flexible, plastic device placed inside a womanâs uterus. Mirena is the brand-name for a type of IUD that releases synthetic progesterone hormone into a womanâs body. The IUD makes it harder for sperm and eggs to move, or for a fertilized egg to lodge in the uterus. It is 99.8% effective in preventing pregnancy, making it slightly more effective than sterilization.