COMPARATIVE EFFECTIVENESS OF CONTEMPORARY WEIGHT-LOSS INJECTIONS AND ESTABLISHED BARIATRIC PROCEDURES

Obesity management has shifted from a traditional lifestyle-versus-surgery framework to a broader continuum that now includes highly effective injectable anti-obesity medications. This revised narrative review compares established injectable therapies used in contemporary obesity care - liraglutide 3.0 mg, semaglutide 2.4 mg, and tirzepatide 5-15 mg - with major bariatric procedures, especially sleeve gastrectomy, Roux-en-Y gastric bypass, and selected duodenal switch procedures. In response to reviewer guidance, the methodology has been strengthened by adding a transparent literature-search strategy, explicit inclusion and exclusion criteria, a non-meta-analytic synthesis rationale, a formal ethical-clearance statement, and a critical-appraisal table of the principal evidence base. Across pivotal trials, mean total body-weight reduction was approximately 7.4% for liraglutide at 56 weeks, 14.9% for semaglutide at 68 weeks, and 20.9% for tirzepatide 15 mg at 72 weeks. In randomized or comparative bariatric literature, 5-year total weight loss was about 22.5% after sleeve gastrectomy and 26.0% after Roux-en-Y gastric bypass, while duodenal switch can exceed these results in selected high-BMI populations. Because medication and surgical estimates come from different trial designs, populations, follow-up durations, and outcome definitions, all comparisons are interpreted as indirect clinical benchmarks rather than exact head-to-head treatment effects. The main conclusion is that metabolic/bariatric surgery remains the most durable intervention for severe obesity, but modern injections have narrowed the efficacy gap and expanded individualized treatment options.