Tirzepatide (LY3298176) is a synthetic, lipidated 39-residue peptide whose sequence is based on glucose-dependent insulinotropic polypeptide (GIP). It contains α-aminoisobutyric acid (Aib) at positions 2 and 13, a C-terminal serine amide, and Lys20 acylated with icosanedioic acid (C20 diacid) through a γ-glutamyl–bis(8-amino-3,6-dioxaoctanoyl) linker.

Tirzepatide has been characterized as a dual agonist of the GIP receptor (GIPR) and the GLP-1 receptor (GLP-1R). Signalling studies report that it mimics native GIP at GIPR but shows bias at GLP-1R, favouring cAMP generation over β-arrestin recruitment, with weaker agonist-driven GLP-1R internalisation than GLP-1; it has been described as an imbalanced agonist with greater GIPR engagement. Cryo-EM and molecular dynamics studies indicate that the lipid moiety, together with the amino-acid sequence, shapes its receptor engagement.

Tirzepatide is used in incretin-receptor pharmacology, biased-agonism and receptor-desensitisation assays, structural biology of class B GPCRs, pancreatic islet cell models, and LC-HRMS analytical method development. Lyophilized material is hygroscopic and should be stored desiccated and protected from light.

Research use only. This material is sold for in-vitro laboratory research and development purposes exclusively. It is not a drug, food, or dietary supplement, has not been evaluated by the FDA, and must not be used in humans or animals.