I am also on Metformin for diabetes. When my doctor first put me on it, he said it can be hard on your liver, but then again you could probably say that about most medicines. He has me going in for once yearly blood tests to make sure my liver is doing ok, in addition to my quarterly A1c.

I will say that my doctor is very conservative, so take it for what you will. He didn't like my first A1c result that was in the low range for diabetics(6.2). From what I understand that is a good number, so who knows. As a side note, my last A1c after going LC was 5.7. Yippee!