A major aim of glucose-lowering therapy in people with diabetes is to delay or prevent the late-developing complications of diabetes that threaten the quality and duration of life. While intensive interventions to control hyperglycaemia may impair well-being to some extent, the balance of quality of life is usually highly positive. Diet and exercise therapy remains the cornerstone of management, and should usually be given a trial alone first. However, the magnitude and duration of benefit from this intervention is insufficient for most people. More frequent, early, use of metformin is an evidence-based strategy for reducing the risk of adverse outcomes of diabetes in people with type 2 diabetes with sub-optimal glucose control on lifestyle measures alone. This has been recognised in recent evidenced-based guidelines from the UK National Institute for Clinical Excellence and from Diabetes UK, which now support the use of metformin as initial pharmacological therapy for all people without contraindications to the drug. Other national and local guideline committees should consider updating their recommendations on diabetes management in line with these findings.