Tirzepatide
Research Overview · Mechanism of Action · Reconstitution Guide
Overview
Tirzepatide is a 39-amino acid synthetic peptide that acts as a dual agonist at both glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptors. It is based on the native GIP sequence with modifications enabling GLP-1R co-agonism. A C20 fatty diacid is attached via a linker to enable albumin binding and extend half-life to approximately 5 days. The dual incretin mechanism produces additive and potentially synergistic metabolic effects not achievable with GLP-1 agonism alone.
Mechanism of Action
GIP receptor activation enhances insulin secretion in a glucose-dependent manner and may directly promote adipocyte lipid uptake and storage in a fed state, while also acting centrally to reduce food intake. GLP-1R activation suppresses glucagon, slows gastric emptying, and activates hypothalamic satiety circuits. The combination produces greater reductions in HbA1c and body weight than either mechanism alone. Tirzepatide also demonstrates preferential GIP receptor agonism at lower concentrations, with GLP-1R activity becoming more prominent at higher doses.
Key Studies & References
Jastreboff AM et al. (2022). Tirzepatide Once Weekly for the Treatment of Obesity. NEJM 387:205–216. SURMOUNT-1: up to 22.5% body weight reduction at 15 mg dose.
Frías JP et al. (2021). Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes. NEJM 385:503–515. SURPASS-2: head-to-head comparison.
Coskun T et al. (2022). LY3298176, a novel dual GIP and GLP-1 receptor agonist for the treatment of type 2 diabetes mellitus. Molecular Metabolism 18:3–14.
Bacteriostatic Water Reconstitution Guide
Research Use Only — The following reconstitution information is provided for in vitro laboratory research purposes only. Not for human or veterinary use.
Recommended Solvent
Bacteriostatic water (0.9% benzyl alcohol)
Standard Volume
Add 2 mL bacteriostatic water to a 5 mg vial to yield a 2.5 mg/mL solution.
Working Concentration
2.5 mg/mL standard reconstitution.
Storage (Reconstituted)
Reconstituted: 2–8°C, use within 28 days. Lyophilized: -20°C.
Stability Window
28 days at refrigeration temperature. Discard if solution becomes cloudy or particulate matter is visible.
Technique
Inject solvent slowly down the vial wall. Gently swirl — do not vortex or shake. Allow 2–3 minutes for complete dissolution.
Notes
Tirzepatide is sensitive to agitation. Gentle handling during reconstitution preserves peptide integrity.
Research Dosing Reference
The following dosing information is derived from published clinical and preclinical research literature and is provided for reference purposes only.
Clinical / Human Research Range
Clinical trials: 5 mg, 10 mg, 15 mg weekly subcutaneous. Escalation from 2.5 mg/week over 20 weeks.
Preclinical Models
Rodent studies: 0.1–1.0 mg/kg subcutaneous, weekly or twice-weekly.
Calculation Example
For a 2.5 mg/mL solution: a 5 mg research dose = 2.0 mL. A 2.5 mg dose = 1.0 mL.