Tirzepatide is a synthetic 39-amino-acid peptide that activates two incretin receptors, GIP and GLP-1. Its chain is based on the GIP sequence, carries two aminoisobutyric acid (Aib) residues, and has a C20 fatty diacid attached through a linker to the lysine at position 20, which lets it bind albumin and makes it a long-acting dual agonist.
This reference collects what a laboratory needs to know about tirzepatide as a material: how its sequence behaves in the vial, what it dissolves in, how it is handled at the bench and what to do when an order arrives. Each section below has its own page.
Molecular reference
| Name | Tirzepatide |
|---|---|
| Also known as | Dual GIP and GLP-1 receptor agonist |
| Sequence | Tyr-Aib-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Tyr-Ser-Ile-Aib-Leu-Asp-Lys-Ile-Ala-Gln-Lys(C20 diacid-γGlu-AEEA-AEEA)-Ala-Phe-Val-Gln-Trp-Leu-Ile-Ala-Gly-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-Pro-Ser-NH2 |
| Residues | 39 |
| Molecular formula | C225H348N48O68 |
| Molecular weight | 4813 g/mol |
| CAS number | 2023788-19-2 |
Formula, molecular weight, CAS number and the residue order are from PubChem (CID 163285897); the Aib positions, the C-terminal amide and the 1,20-eicosanedioic acid on Lys20 are as described in the US prescribing information for the approved medicine.
Four features of that sequence explain most of its behaviour. The Aib residues at positions 2 and 13 favour a helical backbone and resist the enzymes that clip the second residue of incretin peptides, a design principle shared with other long-acting analogues (Lau et al., Journal of Medicinal Chemistry, 2015). The C20 diacid on Lys20 makes the molecule amphiphilic, with a fatty tail on a water-soluble chain, and lipidated incretin analogues are known to form oligomers in water (Přáda Brichtová et al., Bioconjugate Chemistry, 2025). The sequence has no methionine, cysteine, histidine or asparagine, but it does carry a tryptophan at position 25, two tyrosines and two glutamines. And the C-terminal tail, Gly-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-Pro-Ser, is proline-rich and ends in an amide.
What it is studied for
Tirzepatide was designed to test whether adding GIP receptor activity to GLP-1 receptor activity changes metabolic outcomes. In mice it improved glucose tolerance through both receptors, and with chronic administration it lowered body weight and food intake more than a selective GLP-1 receptor agonist (Coskun et al., Molecular Metabolism, 2018). Cryogenic electron microscopy showed it activates the GIP receptor much like native GIP but engages the GLP-1 receptor differently, with less receptor desensitisation, and that the fatty acid modification shapes this behaviour (Sun et al., PNAS, 2022).
In human research, a 40-week phase 3 trial in type 2 diabetes measured HbA1c changes of minus 2.01 to minus 2.30 percentage points across tirzepatide arms against minus 1.86 with semaglutide (Frías et al., New England Journal of Medicine, 2021). In a 72-week phase 3 obesity trial, mean body weight changed by up to minus 20.9% in the top tirzepatide arm against minus 3.1% with placebo (Jastreboff et al., New England Journal of Medicine, 2022). Gastrointestinal effects were the most common adverse events and were mostly mild to moderate. More on the trial record is in tirzepatide trials: weight and diabetes and tirzepatide vs semaglutide.
Stability
Without methionine or cysteine, tirzepatide’s main chemical weak points are its tryptophan and tyrosines under light, and slow changes at two glutamines and two aspartates. Its lipid chain makes physical self-association the bigger concern in solution. The tirzepatide stability page explains each route and how cold, dark storage slows it.
Solubility
Tirzepatide carries a net negative charge at neutral pH, which shapes what it dissolves in and why acidic diluents work against it. The tirzepatide solubility guide covers bacteriostatic water, saline, concentration and the causes of haze.
Handling
Temperature equilibration, gentle swirling, aseptic access and clear labelling matter more for an amphiphilic peptide than for a small, plain one. The tirzepatide handling page lists the bench practice and the common mistakes.
On arrival
What a sealed vial of lyophilised tirzepatide should look like and what to do with it first are on the tirzepatide on-arrival page.
Storage and reconstitution
Fridge and freezer windows, before and after mixing, are on how long tirzepatide lasts. Water volumes and concentrations for the 10 mg and 20 mg vials are on how much bacteriostatic water for a tirzepatide vial.
FAQ
Short answers to the questions researchers ask most about storing, mixing and handling tirzepatide are on the tirzepatide FAQ.
Where to get it
Vistara Labs supplies tirzepatide in 10 mg and 20 mg lyophilised vials for laboratory research, shipped within Canada by Canada Post Xpresspost. There is no nasal spray version. Certificates are on our lab reports page.
All products supplied by Vistara Labs are intended for laboratory research use only. They are not drugs, are not approved for human or veterinary use, and are not intended to diagnose, treat, cure or prevent any condition. Nothing on this page constitutes medical advice or guidance for use in humans.
