Compound Profile: Tirzepatide

Tirzepatide (also LY3298176) is a synthetic linear peptide of 39 amino acids. Its molecular formula is C225H348N48O68 and its average molecular weight is approximately 4,813.5 g/mol. The peptide backbone is based on the sequence of GIP, glucose-dependent insulinotropic polypeptide, with substitutions that confer GLP-1 receptor activity, and it contains two Aib (2-aminoisobutyric acid) residues at positions 2 and 13 that protect it from degradation by dipeptidyl peptidase-4.

At lysine 20 the peptide carries a C20 fatty diacid (eicosanedioic acid) joined through a linker of γ-glutamic acid and two units of 2-[2-(2-aminoethoxy)ethoxy]acetic acid. The fatty diacid binds reversibly to serum albumin, which protects the peptide from renal clearance and enzymatic degradation and extends its circulating half-life in published pharmacokinetic work to around five days. The same strategy is used in semaglutide (C18 diacid) and retatrutide (C20 diacid).

Tirzepatide is described in the literature as an imbalanced dual agonist: it binds the GIP receptor with affinity comparable to native GIP and the GLP-1 receptor with lower affinity than native GLP-1, and it shows biased signalling at the GLP-1 receptor, favouring cAMP production over β-arrestin recruitment. Much of the mechanistic research examines what the GIP receptor component contributes beyond GLP-1 agonism alone, a question that remains open.

The research literature spans receptor signalling studies in cell lines expressing the GIP and GLP-1 receptors; glucose homeostasis and insulin secretion models in isolated islets and in rodents; energy balance, adiposity and hepatic lipid models in preclinical systems; and a large clinical trial programme that is published and referenced widely. In the research-peptide context the compound is used in receptor pharmacology and in comparative work against semaglutide and retatrutide.

Tirzepatide's size and lipidation make it more demanding to analyse than short peptides. On reversed-phase HPLC the fatty-diacid chain increases retention markedly, and the method must be chosen to resolve the main peak from deamidated and oxidised variants. Mass spectrometry confirms the full modified structure by matching the observed mass to the theoretical value, which includes the linker and fatty acid. Regent Peptides supplies tirzepatide in seven vial strengths, UK manufactured, with every batch tested by Janoshik Analytical and the certificate linked to the batch reference.

Tirzepatide is an approved prescription medicine in several jurisdictions under brand names, and the approved product is manufactured, tested and supplied under pharmaceutical regulation. The research-grade peptide supplied here is not that product, is not a medicine, and is supplied solely for in-vitro laboratory research. It is not for human use.