Metformin is the first-line medication for type-2 diabetes in overweight people. But in some studies, metformin has been proposed as a potential medication for adolescent obesity. This study aims to evaluate the effect on extended-release metformin on the BMI of adolescents.

This randomized, multicenter, placebo-controlled, double-blind trial included a total of 39 obese adolescents aged 13-18 years with BMI≥95th percentile. The participants were randomly assigned in a 1:1 ratio to receive metformin intervention or placebo for 48 weeks. The primary outcome of the study was the change in BMI after 48 weeks.

After 48 weeks of starting the treatment, the mean adjusted BMI increased by 0.2 in the placebo group and decreased by 0.9 in the metformin group. The change in BMI scores persisted for 12 to 24 weeks following the cessation of the treatment. There were no significant effects on body composition, insulin indices, or abdominal fat in either of the two groups.

The research concluded that metformin intervention resulted in a small but statistically significant reduction in BMI levels in obese adolescents. Therefore, metformin can be used as a medication for adolescent obesity. However, clinicians should ensure metformin is used with a proper diet and exercise program.