Tirzepatide is a synthetic linear peptide with agonist activity at both the glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptors [1].
GIP and GLP-1 are hormones that regulate blood sugar control while activating and increasing levels of intracellular cyclic adenosine monophosphate in pancreatic B cells, thereby stimulating insulin secretion. Aside from their insulinotropic effects, these hormones also play critical roles in various biological processes in different tissues and organs that express GIPR and GLP-1R, including the pancreas, fat, bone, and the brain [1].
While tirzepatide is a dual GIP/GLP-1 receptor agonist, its binding activity for the GIP receptors is comparable to that of native GIP while being five times lower for the GLP-1 receptors than that of native GLP-1. Research indicates that activation of both the GLP-1 and GIP receptors produces a synergistic effect, with more enhanced insulin response and glucagonostatic response versus separate administration of each hormone [2].
Developed by Eli Lilly, tirzepatide is a 39-amino acid linear synthetic peptide based on the sequence of native GIP, sharing 19 amino acids with human GIP. The peptide includes a C20 fatty diacid moiety conjugated through a hydrophilic linker, which prolongs its duration of action—leading to a half-life of about five days [2].
Following pre-clinical research and phase 1 and 2 clinical trials, tirzepatide was recognized as a potent glucose lowering and weight loss agent with a safety profile that was comparable to other GLP-1 receptor agonists. This has led to its approval by the FDA in May 2022 as a treatment of type 2 diabetes. As a type 2 diabetes prescription medication, it is sold under the brand name Mounjaro [2, 3].
It is available online as a reference material for purchase by licensed researchers and laboratory professionals.
Tirzepatide Dosage Chart | Quick Breakdown
| Timeframe | Weekly Tirzepatide Dose For Weight Loss Research |
| Week 1-4 | 2.5mg |
| Week 5-8 | 5 mg |
| Week 9-12 | 7.5 mg |
| Week 13-16 | 10 mg |
| Week 17-20 | 12.5 mg |
| Week 21+ (maintenance dose) | 15 mg |
- Tirzepatide Treatment Protocol: The research peptide is to be administered once weekly subcutaneously.
