Tirzepatide
Dual GIP / GLP-1 receptor agonist · Research-grade reference material
Identity
- Molecular formula
- C225H348N48O68 (commonly cited — confirm against reference standard before publishing)
- Molecular weight
- ~4813.45 g/mol (commonly cited — confirm against reference standard before publishing)
- CAS number
- 2023788-19-2
Research Background
Tirzepatide is a synthetic dual GIP/GLP-1 receptor agonist peptide, FDA-approved. 39 amino acids, GIP-receptor-agonist backbone with GLP-1 receptor cross-reactivity, conjugated to a C20 fatty diacid moiety. Tirzepatide is a dual agonist, engineered to activate both the GIP and GLP-1 receptors in a single molecule, one step short of retatrutide’s three-receptor design. It is FDA-approved under the brand names Mounjaro (type 2 diabetes) and Zepbound (chronic weight management).
Tirzepatide’s approval rests on an unusually large trial program. The SURMOUNT series (obesity/weight management) and SURPASS series (type 2 diabetes) together enrolled thousands of participants across multiple Phase 3 trials, including a head-to-head comparison against semaglutide.
Lab-tested research material
Mechanism
GLP-1 receptor activation suppresses appetite and delays gastric emptying. GIP receptor activation is studied for enhancing insulin sensitivity and supporting lipid metabolism. Combined in a single molecule, the two pathways are studied for producing more comprehensive metabolic regulation than GLP-1 activation alone (Jastreboff et al.). In a head-to-head trial against semaglutide, tirzepatide produced greater reductions in both body weight and HbA1c in people with type 2 diabetes (Frías et al.).
GIP and GLP-1 are endogenous incretin hormones. Their receptors are expressed in pancreatic tissue and in brain regions relevant to appetite regulation. Tirzepatide co-activates both with a single molecule — the mechanistic feature that separates it from the GLP-1 monotherapy class.
Dual receptor co-agonism. Simultaneous activation of GIP and GLP-1 receptors, which have overlapping and non-overlapping expression and function.
Appetite and intake. Reduced calorie intake, with effects understood to be substantially appetite-mediated.
Gastric emptying. Slowed gastric emptying, a class effect of GLP-1 receptor agonism.
Insulin sensitivity and glycemic control. Improved insulin response; the basis of the original type 2 diabetes indication.
Half-life extension. The C20 fatty diacid moiety supports albumin binding and once-weekly administration in the approved product.
Dual incretin receptor co-agonism. Schematic. Research-grade material supplied here is for in-vitro laboratory use only.
State of the Evidence
Research Evidence: based on 2 sources cited, most recent 2022. Regulatory Status: FDA-approved as Mounjaro (type 2 diabetes) and Zepbound (chronic weight management). Approved by the EMA under equivalent indications. Availability Status: Research Only.
1. Human · Phase 3 RCT — “Tirzepatide Once Weekly for the Treatment of Obesity,” New England Journal of Medicine, 2022. The SURMOUNT-1 trial: participants receiving tirzepatide achieved average weight reductions of 16.0% (5 mg), 21.4% (10 mg), and 22.5% (15 mg) over 72 weeks, versus 2.4% on placebo. DOI 10.1056/NEJMoa2206038
2. Human · Head-to-Head RCT — “Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes,” New England Journal of Medicine, 2021. The SURPASS-2 trial: a direct comparison finding tirzepatide produced greater reductions in HbA1c and body weight than semaglutide 1 mg in people with type 2 diabetes. DOI 10.1056/NEJMoa2107519
What the Literature Supports — and What It Doesn’t
Unlike most compounds in this catalogue, tirzepatide is supported by a large, completed, peer-reviewed Phase 3 programme and holds multiple FDA approvals. The evidence is strong — and it pertains to the approved medicine under clinical supervision, not to research-grade material.
Evidence at a glance
SURMOUNT-1 (N=2,539, non-diabetic adults with obesity/overweight): mean weight reduction 15.0% / 19.5% / 20.9% at 5 / 10 / 15 mg versus 3.1% with placebo at 72 weeks.
SURMOUNT-5 head-to-head versus semaglutide: 20.2% versus 13.7% mean weight loss at 72 weeks; published in NEJM.
Approvals: Mounjaro (May 2022, type 2 diabetes); Zepbound (Nov 2023, chronic weight management); Zepbound for moderate-to-severe obstructive sleep apnea with obesity (2024).
Tolerability: predominantly gastrointestinal. In SURMOUNT-1, nausea 31.0% (15 mg) versus 11.7% placebo; discontinuation for adverse events 6.3%.
Ongoing research in chronic kidney disease, heart failure with preserved ejection fraction, and morbidity/mortality in obesity.
Appropriate characterization: a rigorously evidenced, FDA-approved dual incretin agonist. Any research use of reference-grade material is distinct from clinical use of the approved product, and clinical trial outcomes do not transfer to unapproved material of unverified provenance.
Regulatory & status notes
Selected references
- 1. Jastreboff AM, et al. Tirzepatide once weekly for the treatment of obesity (SURMOUNT-1). N Engl J Med. 2022.
- 2. SURMOUNT-5: tirzepatide versus semaglutide, head-to-head Phase 3b (NCT05822830). N Engl J Med. 2025.
- 3. SURPASS Phase 3 programme in type 2 diabetes (five global registration trials).
- 4. Mounjaro and Zepbound US Prescribing Information. FDA/DailyMed.
Safety Information
Research-use compound. This specific compound has FDA-approved prescribing information for its approved indications; consult the approved product labeling for the full clinical safety profile in that context. Evidence strength varies by population and use case — see the Evidence section above.
This is an FDA-approved compound for specific indications; use outside that approved context, dosing, and population has not been evaluated by the FDA. Consult a qualified clinician. For research and educational purposes only, not for human or veterinary use.
Related Compounds
For research and educational purposes only. Not for human or veterinary use.