I have autoimmune issues (hashimotos thyroiditis along with just plain exaggerated immune responses). I went to a naturopath when I'd had hives on my arms and legs for a year and nothing would help. She told me to look into it and see if I wanted to give it a shot. I read about it and thought it was worth a try. After a couple of weeks the hives went away and never came back. I've been on it 5 or 6 years, now. I'm on the metformin for a similar reason. My body eats my thyroid when I have any kind of allergic reaction and if the reaction is strong enough it goes after my pancreas as well. The metformin works as another anti inflammatory in my case. I have had high fasting blood sugar forever (no one knows why) and even with metformin that hasn't changed. My current doc is a Rockefeller style but he's cool and keeps my prescriptions current since I'm not covered in hives. My lips used to randomly swell like I had injections in them but that stopped with the metformin. I've been on that for 4 years or so.