This report examines a case of systemic hypersensitivity to tirzepatide in a patient with type 2 diabetes. Tirzepatide (Mounjaro®), a dual agonist of glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor, has recently gained FDA approval. Additionally, a literature review was conducted to summarize recent research on tirzepatide's effectiveness and safety.A 67-year-old woman, previously treated with basal insulin, metformin, and semaglutide (a GLP-1 agonist), experienced severe disseminated pruritus and a generalized urticarial rash after her first dose of tirzepatide. This reaction, which subsided with antihistamines, raises questions about possible immunoglobulin Emediated hypersensitivity. The report highlights the need for increased vigilance regarding allergic reactions to new diabetes medications, particularly in the context of GIP/GLP-1 receptor agonists.