The Mirena IUD is 5 years of birth control. It’s made of flexible hormone infused plastic. The insertion was a little uncomfortable but not unbearable, I only had the lightest cramping for about a week and then no more. My monthly cycle was heavier the first month and then began to get lighter until it disappeared completely 5 months post-insertion. Now the downsides, the Mirena IUD has strings made of stuff that feels like fishing line that come out through the cervix by a little bit for easy removal of the IUD; you’re supposed to check them monthly to be sure the IUD is still in place. Problem was that my boyfriend complained that he could feel them during intercourse in some positions and that they hurt. I’m a very active person and I eat a good diet. Without changing anything about my lifestyle, I gained 50 pounds in the year I used it. For those of you planning to have kids after the Mirena, you’ll be happy to learn that I got pregnant the month after removal and carried to term with no trouble.