Question: In obese or overweight (BMI > 25 kg/m2) adults without type two diabetes, how effective is Metformin combined with exercise and a controlled diet, compared to exercise and a controlled diet alone, improving weight related outcomes (e.g. BMI, blood pressure, blood cholesterol, HbA1c)?

Answer:

Overall, the evidence on the effectiveness of adding metformin treatment to lifestyle interventions (exercise and diet) was contradictory and limited to specific population. There was evidence that additional metformin treatment was ineffective in women with polycystic ovary syndrome, but may have some small benefits for people with chronic schizophrenia. Further high quality RCTs and/or appropriate meta-analyses are needed to confirm these findings and to assess the effectiveness of adding metformin treatment to lifestyle interventions in other populations.