I got my Mirena put in a little of a year ago. I absolutely loveeeee it and I did not gain any weight on it. When looking at my options weight gain was one side effect I was trying to avoid at all cost. So I chose the iud among many other reasons. My doctor told me weight gain isn't very common because the hormones released by Mirena are just contained in the uterus and don't travel through the your blood. In which weight gain isn't very common, although it is listed as one in the inserts. I wish you luck and if you have any further questions regarding Mirena I'd be more than happy to help!

Thanks!

Not to scare you, but I got 20 lbs heavier and had cramps for seven months straight. I got it taken out. This doesn't happen to most people, though.