Tirzepatide
Tirzepatide is an approved incretin therapy that combines GIP and GLP-1 receptor activity in a single molecule. Large randomized trials show substantial reductions in HbA1c and body weight, and a head-to-head trial (SURMOUNT-5) reported greater weight loss than semaglutide. It is a prescription medicine used under medical supervision.
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Mechanism
In plain terms, tirzepatide imitates two natural gut hormones that lower blood sugar and reduce appetite. Technically, it is a single peptide that agonizes both the glucose-dependent insulinotropic polypeptide (GIP) receptor and the glucagon-like peptide-1 (GLP-1) receptor. This dual incretin action enhances glucose-dependent insulin secretion, suppresses glucagon, slows gastric emptying, and reduces food intake, producing improvements in glycemic control and body weight.
Regulatory Status by Region
- United States (FDA)Approved. Mounjaro for type 2 diabetes (May 2022); Zepbound for chronic weight management (November 2023) and for moderate-to-severe obstructive sleep apnea in adults with obesity (December 2024).
- Australia (TGA)Registered on the ARTG (Mounjaro) for type 2 diabetes and for weight management, available on prescription.
- European Union (EMA)Authorized (Mounjaro) for type 2 diabetes and weight management (marketing authorization granted September 2022).
- WADANot prohibited. Added to the WADA 2026 Monitoring Program, with markers tracked in- and out-of-competition to detect patterns of misuse; not a banned substance.
Key Studies
- Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1; Jastreboff et al.) (opens in a new tab) (N Engl J Med 2022;387:205-216; DOI 10.1056/NEJMoa2206038; PMID 35658024; NCT04184622)
- Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes (SURPASS-2; Frias et al.) (opens in a new tab) (N Engl J Med 2021;385:503-515; DOI 10.1056/NEJMoa2107519; PMID 34170647)
- FDA approves new medication (Zepbound/tirzepatide) for chronic weight management (opens in a new tab) (U.S. Food and Drug Administration press announcement, November 2023)
Related Clinical Trials
- GLP-1/GIP Receptor Agonists in Obesity-Related HFpEF: The GLIDE-HF RegistryN/A · Not Yet Recruiting
- Tirzepatide for the Treatment of Concurrent Type 1 Diabetes and Overweight or ObesityPhase 2 · Not Yet Recruiting
- Trial of Tirzepatide for the Treatment of Cannabis Use DisorderPhase 2 · Not Yet Recruiting
- Metabolic Surgery for Atrial Fibrillation EliminationPhase 4 · Not Yet Recruiting
- A Study of Weight Loss Intervention With Tirzepatide and Progestin Intrauterine Device to Treat Endometrial Hyperplasia and Grade 1 Endometrial CancerPhase 2 · Not Yet Recruiting
- Effectiveness of Combined GLP-1/GIP Dual Agonist Therapy and Structured Exercise on Skeletal Muscle Morphology, Quality, and Physical Function in Overweight and Obese IndividualsN/A · Not Yet Recruiting
- Impact of Using a GLP1 on Treatment Related Side Effects of Lung Cancer Patients Receiving LorlatinibPhase 1 · Not Yet Recruiting
- Impact of GLP-1 Receptor Agonist Therapy on Alcohol PharmacokineticsPhase 1 · Not Yet Recruiting
Related News & Research
- This Week in Peptide Research: A Kisspeptin Reproductive-Axis Cluster, Survodutide's Liver Mechanism, and Teriparatide's Cost Question
- Real-World Cohort Study in The BMJ Finds Tirzepatide Cut Major Cardiovascular Events by 32% Versus Sitagliptin
- This Week in Peptide Research: Bone-Building Peptide Mechanisms, Real-World GLP-1 Data, and a Reproductive-Axis Cluster
- TGA Issues Class-Wide GLP-1 Warning Over Rare Eye Disorder Linked to Semaglutide and Tirzepatide
- BMJ Study Links GLP-1 Receptor Agonists to Higher Hair Loss Risk in Type 2 Diabetes
Latest research
- Glycemia-based predictors of T2D development in adults with obesity and prediabetes: SURMOUNT-1 post hoc analysis. (opens in a new tab)
Journal of the Endocrine Society · Aug 19, 2026
- Weight loss outcomes with tirzepatide in women with and without self-reported polycystic ovary syndrome. (opens in a new tab)
Journal of the Endocrine Society · Aug 19, 2026
- Comparative effects of semaglutide tirzepatide and retatrutide on renal fibrosis in UUO and aged mice. (opens in a new tab)
iScience · Aug 13, 2026
Common Questions
- What is Tirzepatide?
- Tirzepatide is a once-weekly injectable dual GIP/GLP-1 receptor agonist from Eli Lilly, marketed as Mounjaro (type 2 diabetes) and Zepbound (chronic weight management). It is FDA- and EMA-approved and TGA-registered, supported by the SURPASS (diabetes) and SURMOUNT (obesity) Phase 3 programs.
- Is Tirzepatide approved for medical use?
- Tirzepatide is approved for one or more medical uses in at least one major jurisdiction. United States (FDA): Approved. Mounjaro for type 2 diabetes (May 2022); Zepbound for chronic weight management (November 2023) and for moderate-to-severe obstructive sleep apnea in adults with obesity (December 2024). European Union (EMA): Authorized (Mounjaro) for type 2 diabetes and weight management (marketing authorization granted September 2022). Australia (TGA): Registered on the ARTG (Mounjaro) for type 2 diabetes and for weight management, available on prescription.
- How does Tirzepatide work?
- In plain terms, tirzepatide imitates two natural gut hormones that lower blood sugar and reduce appetite. Technically, it is a single peptide that agonizes both the glucose-dependent insulinotropic polypeptide (GIP) receptor and the glucagon-like peptide-1 (GLP-1) receptor.
- Is Tirzepatide legal in Australia?
- Tirzepatide in Australia (TGA): Registered on the ARTG (Mounjaro) for type 2 diabetes and for weight management, available on prescription.
- Is Tirzepatide banned in sport?
- Tirzepatide under the World Anti-Doping Agency (WADA) code: Not prohibited. Added to the WADA 2026 Monitoring Program, with markers tracked in- and out-of-competition to detect patterns of misuse; not a banned substance.