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.
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.) (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.) (N Engl J Med 2021;385:503-515; DOI 10.1056/NEJMoa2107519; PMID 34170647)
- FDA approves new medication (Zepbound/tirzepatide) for chronic weight management (U.S. Food and Drug Administration press announcement, November 2023)
Related Clinical Trials
- 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
- 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
- Metabolic Surgery for Atrial Fibrillation EliminationPhase 4 · Not Yet Recruiting
- Safety and Efficacy of NA-931 and Tirzepatide in Adults Who Are Overweight or ObesePhase 2 · Not Yet Recruiting
- Tirzepatide in the Treatment of Cannabis Use DisorderPhase 3 · Not Yet Recruiting
- Clinical Study of Local and Systemic Biological Impact of GLP1/GIP-Receptor Agonists in Patients With Breast Cancer: The CLARA TrialPhase 2 · Not Yet Recruiting
- Tirzepatide on Atrial Fibrillation Recurrence After Catheter Ablation in Patients With Obesity and HFpEFPhase 4 · Not Yet Recruiting