L.C.
I have a progesterone IUD that is used for controlling the symptoms of menopause and not for pregnancy prevention but I think most of the answers would be the same. I had no weight gain. Mine is a Marena which lasts 5 years. It was uncomfortable to have inserted and I did have a day of cramping and pain but literally nothing after the 3rd day after insertion. I don't even know it is there. I cannot answer you about the menstrual cycle as I am too old to have periods.....It is an easy and safe method of birth control and the nice ting is that you don't have to think about it!