birth control
"I recently had my second Mirena inserted. I had my first one for 6 years. I had a little bit of spotting for the last year or so, perhaps due to the hormones reducing.  I had gained almost 60 pounds since my first insertion. But it was gradual and I never attributed it to the Mirena. I recently went on a low carb diet...started exercising and voila, 40lbs lost in a 3 month period! I guess it wasn't the Mirena after all. When I got my second one inserted I gained 5 lbs of water overnight and bloated something fierce.  I began to worry, what if I start to gain again? Well I gave it 2 weeks I'm down on the scale lower than ever! I'm a happy Mirena user."