Tirzepatide is a synthetic peptide that activates two incretin hormone receptors: the glucose-dependent insulinotropic polypeptide (GIP) receptor and the glucagon-like peptide-1 (GLP-1) receptor. It is the active ingredient in the FDA-approved medicines Mounjaro and Zepbound, and it has become one of the most widely referenced compounds in metabolic research. PRIME supplies tirzepatide as GLP-2 TZ research peptide, a lyophilized powder sold for laboratory research use only.
What is tirzepatide?
Tirzepatide is a linear synthetic peptide of 39 amino acids. Its backbone is modeled on the native GIP sequence, but it has been engineered so that it also binds and activates the GLP-1 receptor. Several positions carry non-standard amino acids, including alpha-aminoisobutyric acid, which help protect the molecule from rapid breakdown by the enzyme dipeptidyl peptidase-4 (DPP-4). A C20 fatty diacid chain is attached to a lysine side chain through a linker. That lipid chain lets the peptide bind reversibly to albumin, which slows its clearance and is the main reason it acts far longer than the native hormones it is based on.
Tirzepatide was developed by Eli Lilly. In the United States it is approved as Mounjaro for type 2 diabetes and as Zepbound for chronic weight management. Separately from those finished medicines, the compound is supplied as a research material so that laboratories can study incretin receptor pharmacology directly.
A note on naming: the PRIME catalog label GLP-2 TZ is a product name only. Tirzepatide is a dual GIP and GLP-1 receptor agonist. It is not described as an agonist of the GLP-2 receptor, which is a separate target with its own research literature.
How tirzepatide works: mechanism studied in research
Both the GIP receptor and the GLP-1 receptor are class B G protein-coupled receptors. When activated, they signal mainly through the Gs protein and cyclic AMP. In pancreatic beta-cell models, activation of either receptor increases insulin secretion in a glucose-dependent way, meaning the effect appears when glucose is elevated rather than at baseline. This glucose dependence is one of the features that made incretin biology such a large research field.
Beyond the pancreas, GLP-1 receptor signaling has been studied for its effects on gastric emptying and on appetite-related circuits in the brain, largely in animal models. The role of GIP receptor signaling is more debated. It has been investigated in adipose tissue, in lipid handling and in central pathways related to food intake and nausea, and researchers continue to study why combining GIP and GLP-1 receptor activity in one molecule behaves differently from GLP-1 receptor activity alone.
Pharmacology studies have described tirzepatide as an imbalanced dual agonist, with relatively stronger activity at the GIP receptor than at the GLP-1 receptor. Some work has also reported that, at the GLP-1 receptor, it favors cyclic AMP signaling over beta-arrestin recruitment, a property often called biased agonism. These features remain an active area of investigation because they may help explain how its profile differs from single-receptor agonists such as semaglutide.
Areas of research
- Type 2 diabetes: investigated in a large clinical trial program focused on glycemic control, which supported its approval as Mounjaro.
- Weight management: studied in clinical trials in adults with obesity or overweight, which supported its approval as Zepbound.
- Obstructive sleep apnea: investigated in clinical trials in people with obesity and sleep apnea.
- Cardiovascular, kidney and liver outcomes: the subject of completed and ongoing clinical studies, including research on fatty liver disease and heart failure.
- Receptor pharmacology: used in cell-based assays to study dual incretin receptor signaling, signaling bias and receptor internalization.
- Preclinical metabolism: studied in rodent models of diet-induced obesity, energy expenditure and adipose tissue biology.
Tirzepatide key facts
| Property | Detail |
|---|---|
| Compound | Tirzepatide |
| Class | Dual GIP and GLP-1 receptor agonist (incretin peptide analog) |
| Structure | 39-amino-acid synthetic peptide with non-standard amino acids and a C20 fatty diacid side chain for albumin binding |
| Form supplied | Lyophilized (freeze-dried) powder in a sealed vial |
| Research status | FDA-approved as Mounjaro and Zepbound; the PRIME product is supplied for laboratory research use only |
| Storage | Lyophilized: cold, dry and protected from light. Reconstituted: refrigerated, following lab protocol |
Handling and storage in the lab
Lyophilized peptides are most stable when kept dry, cold and away from light. Unopened vials of tirzepatide are generally stored refrigerated or frozen, and they should be allowed to reach room temperature before opening so that moisture does not condense inside the vial.
For laboratory work, lyophilized tirzepatide is commonly reconstituted with a sterile diluent such as bacteriostatic water. Standard practice is to add the diluent slowly along the inside wall of the vial and let the powder dissolve with gentle swirling rather than shaking, since vigorous agitation can cause foaming and may damage peptides. Once in solution, the vial should be labeled with the date and concentration, kept refrigerated and protected from light, and handled with sterile technique each time it is accessed. Repeated freeze-thaw cycles should be avoided; when a solution has to be kept for longer, many labs divide it into single-use aliquots.
These are general handling notes for research material. Follow your institution's protocols and any documentation supplied with the product.
Quality and lab results
For a compound as widely studied as tirzepatide, identity and purity matter, because results from impure or misidentified material are hard to interpret or reproduce. Every PRIME batch has a published certificate of analysis, and you can review the report for your batch on the PRIME lab results page before starting work. Match the lot number on your vial to the report, and keep a copy of the COA with your lab records so the material used in each experiment can be traced later.
Related research
Tirzepatide is usually discussed alongside other incretin-based compounds. For a side-by-side look at the two most studied agents, see semaglutide vs tirzepatide. For the next generation of multi-receptor agonists, read tirzepatide vs retatrutide, which sets the dual agonist against an investigational triple agonist. Background on the single-receptor comparator is in our semaglutide research guide.
Tirzepatide FAQ
Is tirzepatide the same as Mounjaro and Zepbound?
Tirzepatide is the active ingredient in both FDA-approved medicines. Mounjaro and Zepbound are finished pharmaceutical products with their own approved labeling. Research-grade tirzepatide from PRIME is a lyophilized material supplied for laboratory use only and is not a substitute for any approved medicine.
Is tirzepatide a GLP-2 agonist?
No. Tirzepatide acts on the GIP and GLP-1 receptors. GLP-2 TZ is only the catalog name of the PRIME product. The GLP-2 receptor is a different target that is studied separately, mainly in intestinal research.
What is the difference between tirzepatide and semaglutide?
Semaglutide is a selective GLP-1 receptor agonist, while tirzepatide activates both the GIP and GLP-1 receptors. Both carry a fatty acid side chain for albumin binding. Researchers compare them to understand what adding GIP receptor activity contributes to the overall profile.
How should lyophilized tirzepatide be stored in the lab?
Keep unopened vials cold, dry and protected from light. After reconstitution, store the solution refrigerated, avoid repeated freezing and thawing, and use sterile technique whenever the vial is accessed.
Can research-grade tirzepatide be used by people?
No. PRIME supplies tirzepatide strictly for laboratory research. It is not intended for human consumption, and nothing on this page is medical advice or guidance on personal use.
For laboratory research use only. Not for human consumption. Not a drug, food or cosmetic.