Clinical efficacy and cost-effectiveness of metformin in different patient populations: A narrative review of real-world evidence

: Over the past two decades, diabetes pharmacopoeia has flourished, with new drugs that, on top of their glucose-lowering efficacy, have been shown to protect the heart and the kidney. Despite these new opportunities, metformin retains a pivotal role among glucose-lowering agents. As one of the few available insulin sensitizers, metformin is an effective, safe, and overall well-tolerated drug backed by over 60 years of clinical experience, including evidence for potential benefits beyond glucose reduction across different ages, sexes, genetic backgrounds, geographical areas, and stages of disease. Although there is some discussion of whether metformin offers the most effective front-line option in newly diagnosed type 2 diabetes (T2D), it remains a natural companion to all other glucose-lowering agents. Furthermore, metformin comes at a very low cost and, as such, it has extremely high cost-effectiveness, particularly given the serious economic burden associated with diabetes complications. This financial advantage is particularly relevant in resource-constrained healthcare systems, where the affordability of metformin may be instrumental in implementing an effective treatment in an evergrowing number of individuals. We present here compelling real-world evidence in support of the clinical efficacy and cost-effectiveness of metformin across different patient populations, highlighting areas where more population-based studies are needed to further incorporate and consolidate its use in the pharmacological management of T2D.