GLP-1 receptor agonists activate cAMP-PKA-AMPK pathways that suppress NF-κB inflammation and reprogram tumor microenvironments, enhancing CD8 T-cell metabolic fitness while reducing T-cell exhaustion. Real-world data across renal cell carcinoma, lung cancer, colorectal cancer, and neuroendocrine tumors suggest improved overall survival and fewer immune-related adverse events when GLP-1RAs are combined with checkpoint inhibitors. This represents a fascinating convergence of metabolic and immune medicine. The obesity paradox—where excess weight increases cancer risk yet improves immunotherapy responses—may finally have a mechanistic explanation and therapeutic solution. GLP-1RAs appear to harness the immune-rich environment that obesity creates while mitigating its immunosuppressive drawbacks through macrophage repolarization and enhanced T-cell function. However, this is observational data requiring prospective validation. The safety profile combining these drug classes remains incompletely characterized, particularly regarding pancreatitis and immune-related toxicities. While promising, this approach needs rigorous clinical trials before becoming standard oncology practice. The concept of metabolic drugs as immunotherapy adjuncts could reshape cancer treatment paradigms if validated.