Metformin is a first line agent for the treatment of type 2 diabetes that can be used alone or in combination with sulfonylureas, thiazolidinediones, incretin-based drugs, sodium glucose cotransporter-2 inhibitors, or other hypoglycemic agents. Metformin has not been linked to serum enzyme elevations during therapy and is an exceeding rare cause of idiosyncratic clinically apparent acute liver injury.