Dual GIP / GLP-1 agonist
FDA-approved weekly injectable for diabetes and obesity (Eli Lilly).
| Class / type | Dual GIP / GLP-1 agonist |
|---|---|
| Category | Metabolic & Weight |
| Status (Jul 2026) | FDA-approved |
Tirzepatide is a first-in-class 'twincretin' from Eli Lilly that activates two gut-hormone receptors at once. It is sold as Mounjaro for type 2 diabetes and Zepbound for weight management and, more recently, for obstructive sleep apnea in people with obesity.
It is a fully approved prescription drug with a robust trial base (the SURPASS and SURMOUNT programs). As with semaglutide, 'research grade' tirzepatide sold in vials is not the approved medicine.
Tirzepatide agonizes both the GIP and GLP-1 receptors. The GLP-1 arm drives glucose-dependent insulin release, glucagon suppression, slowed gastric emptying and appetite reduction; the added GIP activity is thought to further improve insulin sensitivity and satiety, which may explain its edge over GLP-1-only drugs.
In SURMOUNT-1 (obesity), participants on the 15 mg dose lost about 21% of body weight over 72 weeks. In the SURPASS diabetes trials, A1c fell by up to roughly 2.3%, and tirzepatide outperformed semaglutide 1 mg head-to-head on both glucose and weight.
SURMOUNT-OSA showed meaningful reductions in sleep-apnea severity, leading to the 2024 Zepbound approval for moderate-to-severe OSA with obesity.
Currently among the most effective approved options for both weight loss and blood-sugar control, with an added sleep-apnea indication.
Strong metabolic improvements (lipids, blood pressure, liver fat) accompany the weight loss in trials.
Gastrointestinal effects (nausea, diarrhea, vomiting, constipation, abdominal pain) are the most common and are dose-related; some users report these are harsher than with semaglutide.
Injection-site reactions, fatigue and reported hair loss can occur. It carries the same boxed thyroid C-cell tumor warning and MTC/MEN2 contraindication, and rare pancreatitis and allergic reactions are possible. Weight regain after stopping is expected without maintained habits.
Prescription-only and titrated up gradually to manage GI effects. Like semaglutide, it is generally used as ongoing therapy alongside lifestyle change, since benefits reverse on discontinuation.
Aggressive appetite suppression and faster/larger loss vs semaglutide; potent though sometimes harsher on the gut.
FDA-approved prescription drug (Mounjaro, Zepbound). Gray-market 'research' vials are NOT the approved product.