I am 48 years old and I've been on Prempro for 3 years now. I went on it because my hormones measured real low and I was having extremely heavy periods to the point of becoming anemic, really bad heart palpitations, and extreme fatigue. I don't get a period at all when on the Prempro, which is nice, and I noticed that my hair and nails are in a lot better shape when I'm on it, but I have concerns about taking it. I have started and stopped it about 4 times, but every time the heavy periods came back, and the possibility of those palpitations returning really scares me. I still get an occasional palpitation when on the Prempro, but nothing like it was before. I went to the doctor today and told him I really wish I could get off of it, mostly because it could cause breast cancer and I have more of a weight gain problem on it, but he said to either get off of it and stay off, or give it another 6 months and then decide what to do, because starting and stopping could cause a whole set of problems in itself. I don't see the periods slacking off for a few more yearson their own if I come off of the Prempro, but don't really want to stay on Prempro for that long. I guess what my question is is does anyone know what kind of problems can be caused from starting and stopping Prempro, just in case I do quit them and decide I REALLY need to go back on. I mean can it cause cancer or anything! I didn't think to ask him what he meant by problems it could cause. I'm sitting here wondering whether or not to take my pill tonight. If anyone out there has been told what kind of problems starting and stopping hormone pills can cause, I'd appreciate the information. Thanks