Tirzepatide is a 39-residue dual GIP/GLP-1 receptor agonist studied extensively in cell-based pharmacology. Structure, receptor biology, in-vitro literature and handling for NZ research benches.
The tirzepatide peptide (development code LY3298176) is a 39-residue synthetic peptide and dual GIP/GLP-1 receptor agonist, engineered from the native GIP backbone with substitutions conferring GLP-1 receptor cross-activity. It is one of the most heavily studied dual-agonist peptides in current in-vitro incretin-receptor literature. This profile covers structure, receptor pharmacology and handling for New Zealand research laboratories — strictly for in-vitro use.
What is tirzepatide?
Tirzepatide is a synthetic dual-agonist peptide studied for its binding to both the glucose-dependent insulinotropic polypeptide (GIP) receptor and the glucagon-like peptide-1 (GLP-1) receptor in transfected cell-line assays. Its 39-residue backbone is derived from native GIP, with Aib substitutions at positions 2 and 13 studied for DPP-4 resistance, and a C20 fatty diacid linker at Lys20 studied for reversible albumin association. Average mass is approximately 4813.5 Da.
Tirzepatide identity and specifications
| Attribute | Value |
|---|---|
| Development code | LY3298176 |
| Class | Dual GIP + GLP-1 receptor agonist (research reference) |
| Length | 39 amino acid residues |
| Molecular formula | C225H348N48O68 |
| Average mass | ~4813.5 Da |
| Backbone origin | GIP-derived, GLP-1 cross-reactive |
| Format supplied | Lyophilised powder, research use only |
| Storage (lyophilised) | -20 °C, protected from moisture |
Dual receptor pharmacology in vitro
Tirzepatide's defining research interest is that a single molecule engages two receptor systems in cell-based assays that were previously studied only with separate ligands.
- GIP receptor agonism — studied in adipocyte and cAMP-reporter assay systems for insulin-sensitivity pathway signalling.
- GLP-1 receptor agonism — studied via cAMP accumulation in GLP-1R-transfected cell lines.
- Balanced dual agonism is characterised using parallel receptor-specific reporter assays to separate the two signalling contributions.
- Aib backbone substitutions and the C20 diacid linker are studied for their effect on proteolytic resistance and albumin association in stability assays.
Published in-vitro and structural literature
| Research focus | Assay type | Typical readout studied |
|---|---|---|
| GIP-R binding/activation | cAMP accumulation (GIP-R cell line) | EC50 |
| GLP-1-R binding/activation | cAMP accumulation (GLP-1R cell line) | EC50 |
| Plasma protein stability | Serum incubation + LC-MS | Apparent degradation half-life |
| Selectivity profiling | Receptor panel screening | Fold-selectivity vs off-target GPCRs |
Handling and storage reference
- Supplied as lyophilised powder for reconstitution into assay buffer for bench research only.
- Lyophilised material: stable at -20 °C for 24+ months when protected from moisture.
- Reconstituted working solutions: store at 2–8 °C and use within your validated assay window.
- Avoid repeated freeze–thaw cycles to preserve peptide integrity for reproducible assay results.
Tirzepatide vs semaglutide vs retatrutide: receptor coverage
| Attribute | Tirzepatide | Semaglutide | Retatrutide |
|---|---|---|---|
| Receptors studied | GIP + GLP-1 | GLP-1 only | GIP + GLP-1 + Glucagon |
| Backbone | GIP-derived, cross-reactive | GLP-1(7-37) analog | GIP-derived, triple cross-reactive |
| Albumin-binding linker | C20 diacid, Lys20 | C18 diacid, Lys26 | Fatty-acid diacid linker |
Certificate of analysis expectations
- Batch identifier and synthesis date traceable to the lot record
- HPLC purity ≥98% (typically ≥99% for peptides under 30 residues)
- LC-MS confirmed monoisotopic or average mass within ±0.5 Da of theoretical
- Counterion identity and content (acetate or trifluoroacetate) reported
- Bacterial endotoxin and residual solvents per the analytical method
Sourcing research tirzepatide in New Zealand
Kiwi Peps supplies research-grade tirzepatide verified to the KP-99 Purity Standard (99%+ HPLC-MS), logged batch by batch in The Batch Book. Payment cleared by 2pm NZT ships the same working day under Bench-Ready Dispatch, tracked with NZ Post CourierPost anywhere in New Zealand. Strictly for in-vitro laboratory research.
Frequently asked questions
What is tirzepatide studied for?
Tirzepatide is used in vitro as a dual GIP/GLP-1 receptor reference ligand for receptor-activation assays, selectivity screening and comparative incretin pharmacology.
What is the molecular weight of tirzepatide?
Tirzepatide has an average molecular mass of approximately 4813.5 Da across its 39-residue sequence.
How is tirzepatide different from semaglutide at the receptor level?
Tirzepatide engages both the GIP and GLP-1 receptors in cell-based assays, whereas semaglutide is selective for the GLP-1 receptor only.
How is tirzepatide supplied by Kiwi Peps?
As lyophilised powder verified to the KP-99 Purity Standard, with a HPLC-MS certificate of analysis available through The Batch Book.
How should tirzepatide be stored?
Keep the lyophilised powder at -20 °C, protected from moisture, until reconstituted into assay buffer for bench work.
Is tirzepatide sold for human use by Kiwi Peps?
No. Kiwi Peps supplies tirzepatide strictly for in-vitro laboratory research. It is not labelled, dosed or intended for human or animal use.
