For type 2 diabetes poorly controlled by metformin monotherapy, the addition of any non-insulin antidiabetic drug reduces HbA1c to a similar extent, but with differing effects on weight and hypoglycaemic risk.

Current guidelines recommend metformin as initial therapy in patients with type 2 diabetes.1 With time, as β cell function declines, most patients require additional therapy.2 While there is now an expanding list of drugs available to be used as second-line agents, studies that directly compare the effi cacy of these agents are lacking.1 The choice of a second-line agent is, therefore, less clear. In this meta-analysis, Phung and colleagues address this important issue and evaluate the effi cacy of currently available non-insulin diabetes therapies.