| Feature | Semaglutide | Tirzepatide | Retatrutide |
|---|---|---|---|
| Brand Names | Ozempic®, Wegovy® | Mounjaro® | N/A (Investigational) |
| Manufacturer | Novo Nordisk | Eli Lilly | Eli Lilly |
| Drug Class | GLP-1 receptor agonist | Dual GIP/GLP-1 receptor agonist | Triple GIP/GLP-1/Glucagon receptor agonist |
| Mechanism of Action | Mimics GLP-1 to stimulate insulin, reduce glucagon, slow gastric emptying, and suppress appetite | Mimics both GIP and GLP-1 for enhanced insulin release, satiety, and glucose control | Activates GIP, GLP-1, and glucagon receptors to improve metabolism, suppress appetite, and boost energy expenditure |
| Dosing | Weekly injection (0.25–2.4 mg) | Weekly injection (2.5–15 mg) | Weekly injection (in trials: 1–12 mg) |
| FDA Approval | Approved: • Ozempic for Type 2 diabetes • Wegovy for obesity |
Approved: • Mounjaro for Type 2 diabetes • FDA Fast Track for obesity |
Not yet approved (Phase 2 trials ongoing) |
| Clinical Use | • Type 2 diabetes • Obesity/Weight management |
• Type 2 diabetes • Obesity (pending full approval) |
• Obesity (in trials) |
| Weight Loss (avg) | ~15% body weight (Wegovy) | ~22.5% body weight (SURMOUNT-1) | ~24.2% body weight (Phase 2 trial, 48 weeks) |
| Glucose Control (HbA1c) | ↓ ~1.5–2.0% | ↓ ~2.0–2.4% | Not primary focus, but also lowers glucose |
| Common Side Effects | • Nausea • Vomiting • Constipation • Fatigue |
• Nausea • Diarrhea • Reduced appetite • Mild hypoglycemia |
• GI effects (nausea, vomiting) • Potential lean mass loss • Still under study |
| Advantages | • Well-studied • Effective • Cardiovascular benefit |
• Greater weight loss than semaglutide • Dual action may offer synergistic effect |
• Most potent weight loss to date • May boost metabolism via glucagon receptor |
| Limitations | • GI side effects • Plateau in weight loss |
• GI side effects • Expensive |
• Early-stage • Long-term safety unknown |
