birth control
"I had my Mirena inserted in March 2011. I had it in for 6 months and kept losing weight... it was GREAT! I dropped about 10-15 lbs. The cons for me were: oily hair/skin, back acne (which I never usually have), and severe unexplainable joint pain. I had it removed 3 months ago due to the joint pain, as it was unbearable. I have started gaining weight (~5lbs) so I'm thinking about trying the Mirena again. "