My experience with Mirena has been awful. I had it inserted a little over a year ago (2 months after the birth of my younger son). Since then I had cramping ALL the time, significant hair loss, periods every three weeks, then every two, then every week and a half. They only last three days on average, but I go through a heavy tampon an hour. I lost a lot of weight while on Mirena, but I don't know if that can be attributed to it-just diet and exercise. I had severe bloating, depression and mood swings, complete lack of sex drive (very much unlike me), here's the kicker. When I went to get it out (last week), they couldn't find it. So after 3 ultrasounds, 2 xrays, and a CT scan, they found it. It's perforated my uterus and is floating around in my abdomen. The evil thing has gone rogue!!! I'm scheduled for a laproscopic surgery next week to find the damn thing, followed by a more in-depth surgery to remove the evil.
If you're thinking about getting it---DON'T!!!