I just started metformin. what are effects to expect?

GI upset?: The most common complaint i hear is usually some mild GI upset, like nausea. Having said that, it's still relatively uncommon. Many patients take it (at high doses) with no complaints, improved blood sugars and maybe a tiny bit of weight loss.

Many people that take this medication do not experience any side effects. The most common side effect is GI upset, like stomach pain, nausea, gas, or diarrhea. To reduce the chances of these side effects, you should take your doses with a meal.