My doctor here in the Netherlands told me that mirena has the least hormones of all the birth control treatments and that's why it is recommended. I had cramps here and there in my five years of using it, and normal weight gain, nothing too drastic. It also helped a bit with the facial hair. But you also must know that after the first 3 years, the hormones start decreasing so you might get like me a bit more of the hair shedding and facial hair in the last year or so. Also my period stopped after the first year on it. So for me that was a but worrying.