Metformin can lower the risk of diabetes in those with prediabetes.2 Emerging T2DM therapies, sodium-glucose co-transporter-2 (SGLT2) inhibitors and glucagon-like peptide-1 (GLP-1) agonists, may improve glycaemic control,3,4 but have not yet been evaluated for T2DM prevention. Here, GCG is linked to type 2 diabetes mellitus.