Tirzepatide 20mg· 20mg

Tirzepatide engages both the GIP receptor and the GLP-1 receptor, two class B G-protein coupled receptors expressed on pancreatic beta cells, central nervous system nuclei, and adipose tissue. At the GLP-1 receptor, the peptide functions as a balanced agonist, recruiting Gas and beta-arrestin in proportions that resemble the native ligand. At the GIP receptor, biased signaling has been observed, with relatively preserved cAMP accumulation but attenuated receptor internalization compared with native GIP, a profile thought to limit tachyphylaxis.

Activation of these receptors elevates intracellular cyclic AMP, potentiates glucose-stimulated insulin secretion from pancreatic beta cells, suppresses glucagon release from alpha cells under hyperglycemic conditions, and slows gastric emptying. Within hypothalamic arcuate and dorsomedial nuclei, receptor engagement modulates POMC and AgRP neuronal activity, producing observed reductions in caloric intake in preclinical feeding studies. Additional effects on brown adipose thermogenesis and white adipose lipolysis have been reported in murine models.