Lactic acidosis is so rare - in my hospital career I have never seen it once caused by metformin. Used in women with polycystic ovaries, so not just diabetes, safely. Also has trials in prediabetes and is one of the drugs they are animal testing for increasing lifespans.

I take it and have done on and off for years. I get generic from India. I find it helps when on a low carb diet.

Decreases hepatic glucose production; decreases GI glucose absorption; increases target cell insulin sensitivity.
I would love to know if anyone take this besides T2DM. It could potentially have dietary uses, but I think its best to just stick to creating a good diet, and weigh out your food. If you are going to eat crap food and pay no attention to your diet, you will end up with diabetes anyways and then you will need metformin in the end!
Many diabetics who change their lifestyle/diet/exercise do so to stop taking this.
Oh and its got a black box warning that it can cause lactic acidosis, probably not a great thing to worry about when you're working so hard to recover after workouts.