Lactic Acidosis, in a nutshell, is when lactic acid accumulates in the blood stream at a faster rate than it can be eliminated.

People who have kidney and liver problems already are probably already pre-disposed to this condition, and if they take Metformin, it may make it worse. I don't think it has anything to do with the action it takes to help use insulin better, I would rather think it is a rare side effect.

Let's remember that it is a RARE side-effect (5 in 100,000) and unless you have liver/kidney problems already, you aren't in a higher risk group. The only thing I should note here, is that once diagnosed with Lactic Acidosis, it is fatal in 50% of the cases.

Here's a website that explains metformin and lactic acidosis better than most (more layman's terms)



Kisses,