Is metformin safe to combine with a ketogenic diet? (in a non-diabetic.)

Complicated question: With renal insufficiency, metformin can cause lactic acidosis. So on the surface, there is not a risk of ketoacidosis. But if you eliminate all carbs you may not need metformin, and an extreme ketogenic diet can cause many symptoms and metabolic derangements that i would not want to combine with metformin. Suggestion: moderation. Enough carbs to limit ketosis, and check glu daily. See your md.