Yes, I am on Synthroid. I have been on it for years, and 4 years ago, everything went crazy. My thyroid levels were very low, and my doctor (an endocrinologist) increased my dose, gradually, until I was up to 3.5 mgs a day. I stayed at that high dose for a year or so, and now, she has me taking 3 mg. monday through thursday, and 1.5 mg friday, saturday, and sunday. Sometimes I wonder if this very high dose of synthroid might be the cause of my uterine problems. I am dealing with 4 different doctors, and they all seem to have a different opinion about things. I just hate this! I NEVER had problems like this before........periods were always regular, like clockwork. I have been attributing my screwed up cycles to perimenopause, but last month a uterine biopsy showed hyperplasia, hence my impending surgery. I'm feeling like I need a second opinion before I do anything. Right now, I am taking Megace (sp?) to help control the bleeding. It seems to be helping, but it's also causing my blood sugar to rise. I am on insulin, and this is making it a real challenge to keep it in check. At times, I feel like a science experiment!