Tirzepatide: Structure, Research Overview and Specifications
Tirzepatide (LY3298176) is a synthetic peptide that acts as a dual agonist at the GIP and GLP-1 receptors. It was the first dual incretin agonist to reach the market and is one of the most extensively studied peptides in metabolic research. This page summarises its structure, mechanism, published clinical research and the specifications of the research-grade material we supply.
For in vitro research use only. Not for human or animal use. Nothing on this page is medical advice.
What is tirzepatide?
Tirzepatide is a single 39-amino-acid peptide designed to activate two incretin hormone receptors: the glucose-dependent insulinotropic polypeptide receptor (GIPR) and the glucagon-like peptide-1 receptor (GLP-1R). Its sequence is based on the native GIP backbone, with modifications that add GLP-1-receptor activity and extend its half-life.
It was developed by Eli Lilly and Company. In the laboratory it is used as a reference dual agonist for studying incretin signalling, insulin secretion, receptor pharmacology and comparisons with single (GLP-1) and triple (GIP/GLP-1/glucagon) agonists such as retatrutide.
Chemical data
| Name | Tirzepatide (LY3298176) |
|---|---|
| Class | Synthetic peptide, dual GIP and GLP-1 receptor agonist |
| Structure | 39-amino-acid peptide based on the GIP sequence, with non-standard Aib residues and a C20 fatty diacid attached to lysine 20 via a γ-glutamic acid and two AEEA linkers |
| Molecular formula | C225H348N48O68 |
| Molecular weight | ≈ 4813.5 g/mol |
| CAS number | 2023788-19-2 |
| Appearance | White lyophilised powder |
| Available sizes | 10mg · 15mg |
Available sizes
Mechanism of action
- GIP receptor. Tirzepatide binds the GIP receptor with an affinity comparable to native GIP. This “imbalanced” profile favours GIP over GLP-1 activity.
- GLP-1 receptor. At the GLP-1 receptor it shows biased signalling, favouring cAMP generation over β-arrestin recruitment, which has been linked to reduced receptor internalisation.
- Glucose-dependent insulin secretion. Both incretin pathways enhance insulin release when glucose is elevated, a central focus of metabolic research.
- Extended half-life. The C20 fatty diacid enables albumin binding, giving a reported half-life of about 5 days in humans.
What the published research shows
SURPASS programme (type 2 diabetes)
The phase 3 SURPASS trials evaluated tirzepatide in adults with type 2 diabetes. They reported improvements in glycaemic control compared with placebo and with active comparators, including the GLP-1 agonist semaglutide in a head-to-head trial.
SURMOUNT-1 (obesity)
The 72-week SURMOUNT-1 trial, published in the New England Journal of Medicine (Jastreboff et al., 2022), studied tirzepatide in adults with obesity or overweight without diabetes. It reported dose-dependent mean reductions in body weight of 15.0%, 19.5% and 20.9% across the three dose groups, compared with 3.1% with placebo.
Further research
The SURMOUNT programme has continued with additional trials in different populations, including people with type 2 diabetes and obstructive sleep apnoea, and long-term follow-up in people with prediabetes.
Tirzepatide vs retatrutide
| Tirzepatide | Retatrutide | |
|---|---|---|
| Receptors | GIP + GLP-1 (dual) | GIP + GLP-1 + glucagon (triple) |
| Developer | Eli Lilly | Eli Lilly |
| Length | 39 amino acids | 39 amino acids |
| Development stage | Approved medicine (Mounjaro, Zepbound) | Investigational (phase 3) |
See our retatrutide research overview for more detail.
Regulatory status
Tirzepatide is an approved prescription-only medicine. It is marketed by Eli Lilly as Mounjaro and Zepbound, and is authorised by the FDA, EMA and MHRA for specific indications under medical supervision. Licensed medicines must only be obtained through a prescriber and a registered pharmacy.
The material supplied by Sterling Research is a research-grade reagent. It is not a licensed medicinal product, not equivalent to Mounjaro or Zepbound, and is supplied strictly for in vitro laboratory research. It must not be used in humans or animals.
Storage and handling in the lab
- Store lyophilised powder at −20 °C, sealed and protected from light and moisture.
- Let the vial reach room temperature before opening to limit condensation.
- Prepare solutions to your laboratory’s validated protocols, with appropriate PPE and aseptic technique.
- Lipidated peptides can adsorb to plastics. Follow your protocol for buffer choice and low-binding labware.
Quality
Every batch of tirzepatide we supply is independently tested by Janoshik for purity and identity before it is released for sale.
Related research compounds
Frequently asked questions
What is tirzepatide?
Tirzepatide (LY3298176) is a synthetic 39-amino-acid peptide developed by Eli Lilly that acts as a dual agonist at the GIP and GLP-1 receptors.
How is tirzepatide different from semaglutide?
Semaglutide is a GLP-1 receptor agonist only. Tirzepatide activates both the GIP and GLP-1 receptors, which is why it is described as a dual agonist.
How is tirzepatide different from retatrutide?
Tirzepatide is a dual GIP/GLP-1 agonist. Retatrutide adds glucagon-receptor agonism, making it a triple agonist. Tirzepatide is an approved medicine, while retatrutide is still investigational.
Is research-grade tirzepatide the same as Mounjaro?
No. Mounjaro and Zepbound are licensed medicinal products manufactured and supplied under medical regulation. Research-grade tirzepatide is a laboratory reagent for in vitro research only and is not a medicine.
Which sizes does Sterling supply?
Tirzepatide is supplied as lyophilised research material in 10mg and 15mg vials, for in vitro laboratory use only.
References
- Jastreboff AM, et al. Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1). N Engl J Med. 2022;387:205–216. PubMed 35658024
- SURMOUNT-1 study record. ClinicalTrials.gov NCT04184622
- Tirzepatide. Structure, approvals and chemical identifiers
This page is for scientific information only. Sterling Research Group Ltd supplies tirzepatide strictly as a research reagent for in vitro laboratory use. It is not a licensed medicine, not for human or animal use, and not for diagnostic or therapeutic purposes.