Efficacy and Safety of Anti-Obesity Medications for Weight Loss Maintenance in Adults With Overweight or Obesity: A Systematic Review and Meta-Analysis of Randomised Controlled Trials.
AIMS: This systematic review and meta-analysis aimed to evaluate the efficacy and safety of anti-obesity medications (AOMs) for long-term weight maintenance following initial weight loss in adults with overweight or obesity. METHODS: We searched PubMed, Embase, Web of Science and the Cochrane Library from inception to 31 October 2025. Eligible studies were randomised controlled trials (RCTs) comparing AOMs with placebo during the weight-maintenance phase in adults with overweight or obesity after initial weight loss achieved through lifestyle, dietary, surgical or pharmacological interventions. Outcomes included anthropometric indices, cardiometabolic measures, safety endpoints, quality of life and neuropsychiatric adverse events. Weighted mean differences (WMDs) and odds ratios (ORs), each with 95% confidence intervals (CIs), were pooled for continuous and categorical outcomes, respectively, using fixed-effect or random-effects models as appropriate. Risk of bias was assessed using the Cochrane RoB 2 tool, and certainty of evidence was evaluated using the GRADE framework. The protocol was registered with PROSPERO (CRD420261293040). RESULTS: A total of 12 RCTs comprising 4915 participants met the inclusion criteria. Compared with placebo, AOM therapy during the weight-maintenance phase was associated with prevention of weight regain and additional improvements in anthropometric and cardiometabolic outcomes. AOMs led to further reductions in body weight (BW, WMD: -8.68 kg, 95% CI: -13.25 to -4.11), waist circumference (WC, WMD: -7.16 cm, 95% CI: -10.34 to -3.98) and body mass index (BMI, WMD: -3.58 kg/m2, 95% CI: -5.69 to -1.46). Additional benefits were observed for triglycerides, total cholesterol, low-density lipoprotein cholesterol, systolic blood pressure and diastolic blood pressure. Gastrointestinal adverse events were more common with AOMs, whereas serious adverse events were not significantly increased. Neuropsychiatric adverse events were generally comparable between groups, and available quality-of-life measures favoured AOM treatment. CONCLUSIONS: AOM therapy during the weight-maintenance phase can help prevent weight regain, provide further reductions in body weight and improve cardiometabolic risk factors in adults with overweight or obesity. Gastrointestinal adverse events were more common with AOMs, whereas serious adverse events were not significantly increased. Further long-term trials are needed to clarify optimal treatment strategies and safety.