Is it safe to take Cinnamon Supplements with Metformin?

Dear Ask The Doctor: Will a Cinnamon Supplement interact badly with Metformin?

As far as I know, there are no documented interactions with Cinnamon. Metformin, on the other hand, has an interaction with excessive alcohol intake because it may cause lactic acidosis. So to answer your question, there is no known interaction between Cinnamon supplement and Metformin. I hope this helps.