Metformin is a very safe drug. It probably should be added to the water for everyone. If you eat it with excess carbohydrates, it causes gas/bloating, but if you are eating a low carb diet it usually has very few of those side effects. One potential concern people sometimes are given is long term fatty liver. One pharmacist told me it caused this. I researched it and talked to my diabetologist about it and found out that fatty liver is a result of diabetes/metabolic syndrome and carb intake. It co-exists with metformin use because alot of diabetic/obese people have fatty liver. The mechanism of metformin is causing you to be more sensitive to your own insulin. It works well if you have some pancreatic function left. If you have severe diabetes with no function left, it doesn't help much and you need insulin. Metformin lowers hypertension, raises the good cholesterold, curbs carb craving and improves glucose control. You should start at 500mg and titrate up to 2000 mg over months. It can be taken in a single dose all with dinner, even the non-extended release.