Tirzepatide (LY3298176): Research Reference
Research Use Only. This page is a technical reference for in-vitro laboratory research. Reserve Research compounds are not for human or veterinary use, and nothing here is guidance for administration of any kind.
In simple words
Tirzepatide is a chain of 39 amino acids. It is made in a lab. Amino acids are the building blocks of proteins. It has a fatty tail too. The tail helps it last longer.
Cells have switches on the outside. Tirzepatide can turn on two kinds of switches. Their names are GIP and GLP-1. Scientists use it in the lab to see how these switches send signals into cells.
Reserve Research sells tirzepatide only for lab research. See Tirzepatide on our product page →
Tirzepatide (development code LY3298176) is a synthetic, lipidated 39-amino-acid peptide that activates two class B G-protein-coupled receptors: the GIP receptor (GIPR) and the GLP-1 receptor (GLP-1R). It was developed by Eli Lilly and Company on a GIP-derived backbone. Two α-aminoisobutyric acid (Aib) residues resist DPP-4 cleavage, and a C20 fatty diacid on lysine 20 binds serum albumin. Its CAS number is 2023788-19-2, its formula is C225H348N48O68, and its molecular weight is about 4,813.5 g/mol.
Tirzepatide key facts
| Name | Tirzepatide |
|---|---|
| Development code | LY3298176 |
| Compound class | Synthetic lipidated peptide; dual GIP receptor / GLP-1 receptor agonist |
| Length | 39 amino acids, C-terminal amide |
| Sequence | Y-Aib-E-G-T-F-T-S-D-Y-S-I-Aib-L-D-K-I-A-Q-K*-A-F-V-Q-W-L-I-A-G-G-P-S-S-G-A-P-P-P-S-NH2 (K* = lipidated lysine 20) |
| Lipidation | C20 fatty diacid on the lysine-20 side chain, attached through a γ-glutamic acid and two 8-amino-3,6-dioxaoctanoic acid (AEEA) spacer units |
| CAS number | 2023788-19-2 |
| Molecular formula | C225H348N48O68 |
| Molecular weight | ≈4,813.5 g/mol (monoisotopic ≈4,810.5 Da) |
| Receptor targets | GIPR and GLP-1R (class B GPCRs, Gs/cAMP coupled) |
| Appearance | White to off-white lyophilized powder |
| Storage (lyophilized) | −20 °C, dry, protected from light |
Structure
Tirzepatide’s sequence is built mostly on the native GIP peptide, with residues borrowed from GLP-1 and exendin-4 so it can also engage the GLP-1 receptor. Three design features set it apart from the native hormones:
- Aib at positions 2 and 13. α-Aminoisobutyric acid is a non-coded amino acid. At position 2 it blocks cleavage by dipeptidyl peptidase-4 (DPP-4), which rapidly inactivates native GIP and GLP-1.
- Lipidated lysine 20. A C20 fatty diacid attached through a hydrophilic linker binds non-covalently to serum albumin, which greatly extends the peptide’s persistence in experimental systems.
- Exendin-like C-terminus. The -PSSGAPPPS-NH2 tail matches the C-terminal segment of exendin-4.
Mechanism studied in research models
GIPR and GLP-1R are class B G-protein-coupled receptors. Both signal mainly through Gs, which raises intracellular cyclic AMP (cAMP). Tirzepatide’s profile at the two receptors is deliberately unequal:
- Imbalanced toward GIPR. In the discovery work, tirzepatide bound GIPR with an affinity similar to native GIP, and bound GLP-1R about five-fold more weakly than native GLP-1 (Coskun et al., 2018).
- Biased at GLP-1R. At the GLP-1 receptor, tirzepatide favors cAMP generation over β-arrestin recruitment and causes less receptor internalization than GLP-1. Willard et al. (2020) describe it as an “imbalanced and biased” dual agonist.
- Structural basis. Cryo-electron microscopy structures of tirzepatide bound to GIPR and GLP-1R show how one peptide engages both receptors (Zhao et al., 2022).
How tirzepatide compares with related research peptides
| Compound | Receptors activated | Backbone |
|---|---|---|
| Native GLP-1 | GLP-1R | Endogenous hormone |
| Native GIP | GIPR | Endogenous hormone |
| Tirzepatide | GIPR + GLP-1R | GIP-based, lipidated |
| Retatrutide | GIPR + GLP-1R + glucagon receptor | GIP-based, lipidated |
Laboratory handling and storage
- Lyophilized powder: store at −20 °C, sealed and dry, away from light. Let the vial reach room temperature before opening.
- Solvent: labs commonly reconstitute in sterile bacteriostatic water for multi-use stock solutions. Solubility depends on pH and concentration; vendor data show solubility rising at mildly basic pH.
- Prepared solutions: keep at 2–8 °C, minimize agitation, and avoid repeated freeze–thaw cycles. Lipidated peptides can stick to some plastics, so low-binding tubes help.
What a tirzepatide certificate of analysis should show
- Identity: mass spectrometry consistent with ≈4,813.5 g/mol (average) for the intact lipidated peptide.
- Purity: chromatographic purity reported for the specific batch.
- Batch traceability: a lot number that matches the vial label.
Every Reserve Research batch is tested by an independent lab. You can look up any batch number on our COA verification page.
Frequently asked questions
What is tirzepatide?
Tirzepatide (LY3298176) is a synthetic 39-amino-acid lipidated peptide that activates both the GIP receptor and the GLP-1 receptor. Laboratories use it to study dual incretin-receptor signaling.
What is the CAS number for tirzepatide?
2023788-19-2.
What is the molecular weight and formula of tirzepatide?
C225H348N48O68, with an average molecular weight of about 4,813.5 g/mol.
What receptors does tirzepatide activate?
The GIP receptor (GIPR) and the GLP-1 receptor (GLP-1R). Its activity is weighted toward GIPR, and at GLP-1R it favors cAMP signaling over β-arrestin recruitment.
What is the difference between tirzepatide and retatrutide?
Tirzepatide is a dual agonist (GIPR and GLP-1R). Retatrutide is a triple agonist that also activates the glucagon receptor. Both are lipidated 39-amino-acid peptides built on a GIP-based backbone.
Why does tirzepatide contain Aib?
α-Aminoisobutyric acid (Aib) at position 2 blocks cleavage by the enzyme DPP-4, which quickly breaks down native GIP and GLP-1. A second Aib sits at position 13.
How should tirzepatide be stored?
Store the lyophilized powder at −20 °C, dry and protected from light. Keep reconstituted solutions at 2–8 °C and avoid repeated freeze–thaw cycles.
Is Reserve Research tirzepatide sold for laboratory research only?
Yes. It is sold strictly for in-vitro laboratory research. It is not a drug or supplement, and it is not for human or veterinary use.
Research-grade tirzepatide from Reserve Research
Tirzepatide is supplied as a lyophilized powder in sealed vials, independently tested batch by batch, with the COA available through the product page and /verify. Related: retatrutide reference, cagrilintide reference and bacteriostatic water.
References
- Coskun T, Sloop KW, Loghin C, et al. Molecular Metabolism. 2018;18:3–14. doi:10.1016/j.molmet.2018.09.009
- Willard FS, Douros JD, Gabe MBN, et al. JCI Insight. 2020;5(17):e140532. doi:10.1172/jci.insight.140532
- Zhao F, Zhou Q, Cong Z, et al. Nature Communications. 2022;13:1057. doi:10.1038/s41467-022-28683-0
- ChEBI entry CHEBI:194186 (tirzepatide): formula, mass and structural description. ebi.ac.uk/chebi
Last reviewed: October 2026. This page summarizes published laboratory literature for reference. It makes no claims about the safety or effectiveness of any compound in humans or animals.