Molecular Bioengineering Meets Pharmacovigilance: Incretin Receptor Agonists as a Paradigm of Rational Therapeutic Evolution and Emerging Safety Questions

The development of engineered incretin receptor agonists represents a leading example of rational molecular bioengineering in contemporary metabolic medicine. This narrative review examines the evolution from selective glucagon-like peptide-1 receptor agonism to dual and triple receptor agonism, highlighting how peptide engineering has expanded therapeutic efficacy from glycemic control to substantial improvements in obesity, cardiovascular disease, chronic kidney disease, heart failure with preserved ejection fraction and metabolic dysfunction-associated steatohepatitis. Landmark clinical evidence supports these benefits, yet the broadening physiological effects of multi-receptor agonists have increased the complexity of long-term safety evaluation. Gastrointestinal adverse events are common but generally manageable; emerging signals related to gastric motility, ocular complications, cholelithiasis and electrolyte disturbances warrant ongoing pharmacovigilance scrutiny. Incretin receptor agonists thus provide a valuable paradigm for understanding how advances in molecular design must be accompanied by adaptive regulatory science, continuous post-marketing surveillance and rigorous benefit-risk assessment throughout the therapeutic life cycle. Finally, the review examines a further, underexplored consequence of this trajectory: pharmacological appetite suppression at population scale converges with the growing market of minimalist nutrition — liquid meal replacements and supplement-based diets — raising the question of what chronic digestive disuse may entail, evaluated against the established literature on parenteral nutrition, bowel rest and starvation.