Abstract. Glucagon-like peptide-1 (GLP-1) receptor agonists have become a cornerstone in the management of type 2 diabetes mellitus (T2DM) and obesity. Among them, semaglutide stands out as one of the most potent agents, demonstrating robust glycemic control, substantial weight reduction, and cardiovascular risk mitigation. GLP-1 agonists exert their effects through glucose-dependent insulin secretion, suppression of glucagon release, delayed gastric emptying, and central appetite regulation. Semaglutide, with its extended half-life and convenient weekly dosing, offers superior metabolic outcomes compared to earlier GLP-1 analogs. Landmark trials such as SUSTAIN, STEP, and SELECT highlight its efficacy in glycemic control, weight loss, and cardiovascular event reduction. Despite its benefits, semaglutide is associated with gastrointestinal side effects and rare risks such as pancreatitis. This review synthesizes current knowledge on GLP-1 agonists, emphasizing semaglutide’s mechanisms, clinical efficacy, safety profile, and future innovations in metabolic medicine.