— Research monograph
Tirzepatide
The dual GIP/GLP-1 receptor agonist studied in the SURMOUNT and SURPASS programs.
- Class
- Dual GIP / GLP-1 receptor agonist (synthetic 39-amino-acid peptide)
- Half-life (research)
- ~5 days (preclinical and clinical).
- Origin
- Developed by Eli Lilly. First characterized in the open scientific literature in 2018 (Coskun et al.). Approved by the FDA as Mounjaro (2022) for type 2 diabetes and as Zepbound (2023) for chronic weight management.
- Solubility
- Reconstitutes in bacteriostatic water; clear solution.
What is Tirzepatide?
Tirzepatide (research code LY3298176) is a synthetic 39-amino-acid peptide engineered to act as a single-molecule dual agonist at the glucose-dependent insulinotropic polypeptide (GIP) receptor and the glucagon-like peptide-1 (GLP-1) receptor. The molecule incorporates a C20 fatty-acid moiety that supports extended duration of action via albumin binding.
Tirzepatide is a regulated therapeutic compound approved for human use under separate brand names in regulated channels. The Merit Sciences offering is supplied for research use only — not for human or veterinary administration. Researchers must confirm jurisdictional eligibility before procurement.
How does Tirzepatide work?
Binds and activates both the GIP receptor and the GLP-1 receptor with picomolar affinity. The dual-incretin pharmacology is reported to produce additive effects on insulin secretion and glucagon suppression in preclinical metabolic research models.
What the research shows
- In SURMOUNT-1 (NEJM 2022), a 72-week randomized trial in 2,539 adults with obesity, participants in the highest-dose arm saw a mean body-weight reduction of roughly 20.9% from baseline versus about 3.1% on placebo — the largest effect reported for an incretin agent at the time of publication.
- In SURPASS-2 (NEJM 2021), tirzepatide was compared head-to-head against semaglutide 1 mg in type-2-diabetes research; all three tirzepatide doses produced greater reductions in HbA1c and body weight than semaglutide in the study population.
- The dual mechanism — simultaneous agonism at the GIP and GLP-1 receptors — is the design feature most cited in the literature as the basis for its effect size relative to single-incretin GLP-1 agonists.
- Gastrointestinal effects (nausea, diarrhea) were the most frequently reported adverse events across the trial program, generally mild-to-moderate and most common during dose escalation.
Research applications
- Incretin signaling research
- Glucose homeostasis models
- Dual receptor pharmacology
- Body weight regulation studies
- Comparative GLP-1 / GIP agonist work
Handling & reconstitution
Tirzepatide ships as a sealed, lyophilized (freeze-dried) powder and is reconstituted with bacteriostatic water for laboratory handling. Reconstitutes in bacteriostatic water; clear solution. Concentration equals vial mass divided by diluent volume.
See the Tirzepatide reconstitution protocol for a step-by-step guide and an interactive research calculator (vial size → diluent → draw volume).
Frequently asked questions
What is tirzepatide?
Tirzepatide (research code LY3298176) is a synthetic dual agonist that activates both the GIP and GLP-1 receptors. It is the compound studied in the SURMOUNT (obesity) and SURPASS (type-2-diabetes) clinical-trial programs. Merit supplies it as a lyophilized research compound for research use only — not for human or veterinary use.
How does tirzepatide work?
It is a "dual incretin" — a single peptide engineered to activate two gut-hormone receptors at once (GIP and GLP-1). Published trials attribute its effect size relative to single-receptor GLP-1 agonists to this combined mechanism. Mechanistic descriptions here summarize published findings and are not clinical claims.
What did the tirzepatide trials show?
In SURMOUNT-1, the highest-dose arm showed a mean body-weight reduction of about 20.9% over 72 weeks versus ~3.1% on placebo. In SURPASS-2, it produced greater HbA1c and weight reductions than semaglutide 1 mg. See the linked SURMOUNT-1 and SURPASS-2 summaries for trial design and full outcomes.
How is tirzepatide reconstituted for research?
A lyophilized vial is reconstituted with bacteriostatic water; concentration equals vial mass divided by diluent volume. See the Tirzepatide reconstitution protocol for a step-by-step guide and a research calculator. This is reference information for laboratory handling, not a dosing recommendation.
Is Merit tirzepatide for human use?
No. It is sold strictly for research use only — not for human or veterinary use, and not for diagnostic or therapeutic use. Every lot ships with a certificate of analysis documenting ≥99% HPLC purity.
References
- LY3298176, a novel dual GIP and GLP-1 receptor agonist for the treatment of type 2 diabetes mellitus. Coskun T, Sloop KW, Loghin C, et al.. Molecular Metabolism, 2018 · PMID 30473097
- Efficacy and safety of LY3298176, a novel dual GIP and GLP-1 receptor agonist, in patients with type 2 diabetes: a randomised, placebo-controlled and active comparator-controlled phase 2 trial. Frias JP, Nauck MA, Van J, et al.. The Lancet, 2018 · PMID 30293770
- Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes. Frias JP, Davies MJ, Rosenstock J, et al.. New England Journal of Medicine, 2021 · PMID 34170647
- Tirzepatide Once Weekly for the Treatment of Obesity. Jastreboff AM, Aronne LJ, Ahmad NN, et al.. New England Journal of Medicine, 2022 · PMID 35658024
For research use only. Not for human or veterinary use. Not FDA-approved. Reference information summarized from published literature — not medical or dosing advice.