Last reviewed: October 2026 · Cleared Peptides research team
Tirzepatide (development code LY3298176) is a synthetic, lipidated 39-amino-acid peptide characterized as a dual agonist of the glucose-dependent insulinotropic polypeptide receptor (GIPR) and the glucagon-like peptide-1 receptor (GLP-1R). It is a widely used reference compound for studying how co-activation of these two incretin receptors differs from GLP-1R activation alone.
In this guide:
- Structure and identifiers
- Receptor pharmacology
- Signaling bias
- Comparison with related compounds
- Purity testing
- FAQ
Other names
The heading on this page stays the published compound name, because that is the name researchers search. The catalog code is the label Cleared Peptides prints on that research material. It is the same substance, not a second compound, and it is not a CAS name.
| Published name | Tirzepatide |
|---|---|
| Development code | LY3298176 |
| CAS number | 2023788-19-2 |
| Catalog code | CP-T |
| Informal names | Tirz. This code is not CP-Reta and not CP-SEMA. |
Tirzepatide Structure and Identifiers
| Name | Tirzepatide |
|---|---|
| Development code | LY3298176 |
| CAS number | 2023788-19-2 |
| PubChem CID | 166567236 |
| Molecular formula | C225H348N48O68 |
| Molecular weight | ≈4813.5 g/mol |
| Length | 39 amino acids |
| Backbone | Based on the native GIP sequence, with Aib residues at positions 2 and 13 and a C-terminal amide |
| Lipidation | C20 fatty diacid on Lys20 through a γGlu–2×OEG linker |
| Physical form (research grade) | Lyophilized white powder |
Like other long-acting incretin-receptor peptides, tirzepatide combines protease-resistant non-coded residues (Aib) with a fatty diacid side chain that binds serum albumin. Its sequence borrows from GIP, GLP-1 and exendin-4, which is why it is often described as an “imbalanced” dual agonist that favors the GIP receptor.
Tirzepatide Receptor Pharmacology (In-Vitro)
In published assays with recombinant human receptors, tirzepatide shows potency at GIPR comparable to native GIP, and lower potency at GLP-1R relative to native GLP-1. It has negligible reported activity at the glucagon receptor — the key pharmacological difference from retatrutide.
Signaling Bias at the GLP-1 Receptor
A frequently cited finding is that tirzepatide shows biased agonism at GLP-1R: it favors cAMP generation over β-arrestin recruitment, and produces less receptor internalization than native GLP-1 in cell models. This makes tirzepatide a useful tool for laboratories studying biased signaling and receptor trafficking of class B GPCRs.
Tirzepatide Compared with Semaglutide and Retatrutide
| Compound | Receptors (in vitro) | Lipid chain | CAS |
|---|---|---|---|
| Semaglutide | GLP-1R | C18 diacid | 910463-68-2 |
| Tirzepatide | GIPR + GLP-1R | C20 diacid | 2023788-19-2 |
| Retatrutide | GIPR + GLP-1R + GCGR | C20 diacid | 2381089-83-2 |
Read the full tirzepatide vs retatrutide vs semaglutide comparison.
Tirzepatide Purity and Analytical Testing
Research-grade tirzepatide should be supplied with HPLC purity data, mass-spectrometry identity confirmation and a lot-specific COA. Every lot of Cleared Peptides tirzepatide (CP-T) is independently tested, and results are posted on our COA page. Store lyophilized material at −20 °C, sealed and protected from light.
Frequently Asked Questions
What is tirzepatide?
Tirzepatide (LY3298176) is a synthetic 39-residue lipidated peptide characterized in vitro as a dual agonist of the GIP and GLP-1 receptors.
What is the CAS number of tirzepatide?
2023788-19-2. Molecular formula C225H348N48O68, MW ≈4813.5 g/mol.
How is tirzepatide different from retatrutide?
Tirzepatide acts at GIPR and GLP-1R; retatrutide additionally activates the glucagon receptor.
Is CP-T the same as tirzepatide?
Yes. CP-T is Cleared Peptides’ code for research-grade tirzepatide, verified per lot by HPLC and MS.
Is tirzepatide from Cleared Peptides for human use?
No. It is for laboratory research use only, not for human or veterinary use.
Selected References
Peer-reviewed literature on the compounds discussed in this guide, listed as scientific background for laboratory researchers. Citation does not imply endorsement by the authors or any use other than in-vitro research.
- Willard FS, et al. Tirzepatide is an imbalanced and biased dual GIP and GLP-1 receptor agonist. JCI Insight. 2020;5(17). PubMed 32730231 · DOI
Laboratory note: solubility depends on salt form and solvent. This guide does not state a single solubility figure. Handling of lyophilized material is described in the peptide storage guide.
Research Use Only Notice
This guide is provided for educational and laboratory reference purposes. It summarizes published, primarily in-vitro and structural research literature and does not describe, recommend or imply any use in humans or animals. Products sold by Cleared Peptides are for laboratory research use only; they are not drugs, foods, cosmetics or dietary supplements, are not FDA-approved, and are not intended to diagnose, treat, cure, mitigate or prevent any disease. No dosing, administration or therapeutic information is provided.
