Hi Sarah! I am a Type 1 and just started metformin this week. I had actually taken it in the past, but took myself off it when I was having really bad stomach issues. I thought it was from the meds, but it turned out I also have celiac disease. I am in a preconception program now, and have been having trouble getting my A1C under 6 and loosing weight. Our stories sound similar, I am on a 1400-1500 calorie diet, exercise 3-5x per week but no matter what i do the weight keeps piling on. Especially with each insulin increase. I am now up to 52 units a day, which was an increase from around 40 and just in that 4 wk increase I gained 10 lbs. It is a vicious cycle, metformin helped me break this cycle in the past by reducing my insulin needs significantly which along with diet and exercise helped me drop some weight. Good luck to you, glad to know there are other T1s out there trying this!