Metformin, a molecule belonging to the biguanide family, is one of the best known and most widely used drug for the management of diabetes mellitus therapy in the world.
During sixty years of its use, countless benefits have been described, not only for the treatment of diabetes mellitus. However, due to sim-ilarity with other members of the drug family, concern remains high about the risk of developing lactic acidosis. This article attempts to take stock of the real risks associated with the use of metformin, trying to shed light on the real risks and the possible onset of lactic acidosis or renal damage. Metformin-induced lactic acidosis exists but is rare. Appropriate use of the drug, under safe conditions, induces benefits in the absence of risks.