The review summarizes the latest anti‑obesity drugs up to February 2025, focusing on how they work and how well they help people lose weight. It highlights tirzepatide—a drug that activates both GLP‑1 and GIP receptors—as a strong weight‑loss option compared with older meds like orlistat or phentermine‑topiramate.

In this narrative review we describe the recent updates regarding anti-obesity medications as of February 2025. We describe the physiologic mechanisms underpinning the development of hunger, satiation, and maintenance of satiety to address targets for anti-obesity medications. The efficacy, mechanism, and additional beneficial effects of anti-obesity medications are then further detailed. For this review, we focus on FDA-approved medications for obesity and on select medications currently under development and undergoing Phase 2 and 3 trials. We start by focusing on the non-incretin anti-obesity medications orlistat, phentermine, phentermine-topiramate, and naltrexone-bupropion. We also highlight setmelanotide for heritable obesity. The mechanism of action and comparative efficacy of the GLP-1 receptor agonists liraglutide and semaglutide are reviewed. Tirzepatide, the GLP-1 and GIP-receptor dual agonist is described, and weight loss is compared to alternative anti-obesity medications. Additional incretin targets in the pipeline include dual co-agonists to glucagon and GLP-1 receptors, triple agonists targeting glucagon, GLP-1 and GIP, novel GLP-1 agonists, oral formulations of GLP-1 agonists, and amylin agonists. Finally, we provide best practices for adjuncts to pharmacologic treatments of obesity, monitoring efficacy of obesity treatments, and adjusting medication regimens for providers.