Research

Mixed

Among individuals with overweight or obesity who achieve initial weight loss (≥5%) in the first year, long-term maintenance of that weight loss (years 6-15) is significantly greater for those assigned to metformin compared to those assigned to intensive lifestyle intervention (ILS).

If you have prediabetes or are at high risk, achieving even a modest 5% weight loss in the first year is a strong predictor of long-term success. For those who achieve this, adding metformin (if prescribed) may help you keep the weight off better than lifestyle changes alone over the long haul (10+ years). It acts as a maintenance aid rather than just an initial weight loss tool.

GoodQualifiesHIGH confidence
Among persons with weight loss of at least 5% after 1 year, those originally randomly assigned to metformin had the greatest loss during years 6 to 15.
John W. Apolzan et al. · Annals of Internal Medicine · 2019

Why this rating

Based on a large, long-term (15 years) randomized controlled trial (DPP/DPPOS) with high retention, though the specific analysis is a post-hoc subset analysis.

Source

Long-Term Weight Loss With Metformin or Lifestyle Intervention in the Diabetes Prevention Program Outcomes Study

John W. Apolzan et al. · Annals of Internal Medicine · 2019

DOI 10.7326/m18-1605

rct · n=3234Cited 149×
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DOI resolved against Crossref · corpus check 2026-06-10

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