Medical Management of Obesity: A Comprehensive Review of Food and Drug Administration (FDA)-Approved and Investigational Therapies.
This narrative review synthesizes the current landscape of FDA-approved and investigational pharmacotherapies for obesity management. The authors examine six approved long-term agents — orlistat, phentermine/topiramate, naltrexone/bupropion, liraglutide, semaglutide, and tirzepatide — covering their mechanisms of action, pivotal efficacy data, safety profiles, indications, and prescribing considerations. The review notes that semaglutide and tirzepatide have substantially raised expectations for pharmacological weight loss compared to older agents. Emerging investigational compounds, including oral GLP-1 receptor agonists such as orforglipron and multireceptor agonists such as retatrutide, are highlighted as showing even greater early-phase efficacy signals. Common safety considerations discussed include gastrointestinal adverse effects, gallbladder events, pancreatitis risk, thyroid C-cell tumor warnings, teratogenicity, and cost and access barriers. The authors emphasize that patient selection should be guided by BMI, comorbidities, and contraindications. Key limitations acknowledged by the review include a lack of direct head-to-head comparative trials, limited long-term cardiovascular outcomes data, and questions about weight durability after treatment discontinuation. The authors identify these gaps as priorities for future research.
Why this grade: This is a narrative review synthesizing existing literature rather than generating new primary data, so it is graded as review-level evidence; it does not conduct original trials or meta-analytic pooling.
The global rise in obesity has accelerated both clinical and pharmaceutical innovation in antiobesity pharmacotherapy. This narrative review synthesizes current evidence on Food and Drug Administration-approved medications and emerging investigational agents that are shaping clinical practice. We summarize mechanisms of action, pivotal efficacy data, safety profiles, indications, prescribing guidance, and key uncertainties. Approved long-term agents, orlistat, phentermine/topiramate, naltrexone/bupropion, liraglutide, semaglutide, and tirzepatide, differ in mechanism, weight-loss magnitude, and safety considerations. Semaglutide and tirzepatide have redefined expectations for pharmacological weight loss, while next-generation drugs, such as oral glucagon-like peptide 1 receptor agonists (e.g., orforglipron) and multireceptor agonists (e.g., retatrutide), show even greater efficacy in early studies. Common safety concerns include gastrointestinal effects, gallbladder events, pancreatitis risk, thyroid C-cell tumor warnings, teratogenicity, and cost barriers. Appropriate patient selection depends on body mass index, comorbidities, contraindications, and treatment goals, with close monitoring throughout therapy. Long-term data on cardiovascular outcomes and posttreatment weight durability are emerging. Future research should prioritize direct comparative trials, real-world effectiveness, long-term safety, and strategies to improve access and adherence. This review offers clinicians a concise, evidence-based guide for obesity pharmacotherapy and outlines key research priorities as the treatment landscape rapidly evolves.
Educational summary of published research — not medical advice. License: cc by. Full text is shown only where licensing permits.