What Is Tirzepatide (GLP-2 TRZ)?
Tirzepatide is a once-weekly injectable synthetic peptide that acts as a dual agonist at both the GIP receptor (GIPR) and the GLP-1 receptor (GLP-1R). It was developed by Eli Lilly and has received FDA approval under the brand names Mounjaro (type 2 diabetes) and Zepbound (obesity). As a research compound, it offers a valuable tool for studying incretin biology and the differential contributions of GIP vs. GLP-1 signaling to metabolic regulation.
Mechanism of Action
GLP-1 Receptor Agonism
GLP-1R agonism enhances glucose-stimulated insulin secretion, suppresses glucagon, slows gastric emptying, and reduces appetite through both central (hypothalamic) and peripheral mechanisms. These effects collectively contribute to improved glycemic control and reduced caloric intake in research models.
GIP Receptor Agonism
GIP was historically considered a pro-adipogenic hormone, but research increasingly suggests that GIPR agonism in combination with GLP-1R agonism produces additive or synergistic benefits on energy balance. GIP receptor activation may also help mitigate some of the nausea associated with pure GLP-1 agonism by modulating central GLP-1R-driven emetic pathways.
Dual Agonism Synergy
The dual agonist mechanism of tirzepatide appears to produce greater reductions in body weight and HbA1c than equipotent doses of GLP-1 single agonists in published clinical trials. The mechanistic basis for this synergy is an active area of research.
Research Comparison
| Compound | Receptor Target(s) | Weight Research | Status |
|---|---|---|---|
| Tirzepatide (GLP-2 TRZ) | GIP + GLP-1 | Up to ~22% BW reduction (SURMOUNT trials) | FDA approved (Mounjaro/Zepbound) |
| Semaglutide | GLP-1 | Up to ~15% BW reduction (STEP trials) | FDA approved (Ozempic/Wegovy) |
| Retatrutide (GLP-3 RT) | GLP-1 + GIP + Glucagon | Up to ~24% BW reduction (Phase 2) | Clinical trials |
Storage & Handling
Store lyophilized Tirzepatide at โ20ยฐC. Protect from light and moisture. After reconstitution with bacteriostatic water, store at 2โ8ยฐC and use within 30 days. Do not freeze reconstituted solution.
For research use only. Not for human or animal use. Order GLP-2 TRZ here.