Tirzepatide acts as an agonist for both the glucagon-like peptide 1 receptor (GLP-1R) and G protein-coupled receptor 119 (GPR119), effectively inducing cAMP production in HEK293 cells that express either human GLP-1R or GPR119, with EC50 values of 6.54 and 1.01 nM, respectively. Additionally, at a concentration of 100 nM, it triggers receptor internalization in these cells. In vivo studies demonstrate that tirzepatide, administered at 10 nmol/kg per day, significantly reduces body weight, food intake, as well as plasma and hepatic triglyceride levels, free fatty acids (FFAs), leptin, and blood glucose in mice with high-fat diet-induced obesity. Furthermore, a dose of 50 nmol/kg every three days prevents an increase in eosinophils and lymphocytes in the bronchoalveolar lavage fluid (BALF) and inhibits bronchoconstriction prompted by methacholine in mice models of both asthma and diabetes, indicating its potential in treating type 2 diabetes mellitus.