Metformin was the first medicine I tried. That was 6 or 7 years ago. It gave me such an upset stomach that we went on to something else. I ended up on Avandia which worked very well. When it came time to leave that behind we first went to other newer drugs which the insurance company was not willing to pay for. So we went back to metformin. It caused such intestinal problems that I could not leave the house and had to spend most of my time within just a few feet of the bath room.
I am now on Glipizide, and while it is working, it isn't enough on it's own. I am still in the process of getting the answer; and that answer will not include metformin.
Good Luck to you. I really hate this trial and error period, but since everyone's diabetes is different, this is how it has to be done.
"Life isn't about waiting for the storm to pass...
It's about learning to dance in the rain."