Zepbound
Also known as: Tirzepatide for weight loss, High-dose tirzepatide
Zepbound is the brand name for tirzepatide when prescribed for chronic weight management, FDA-approved in November 2023. It contains the same dual GIP/GLP-1 agonist as Mounjaro but is indicated for obesity and overweight with weight-related comorbidities.
Last updated: January 28, 2026
What is Zepbound?
Zepbound is the brand name for tirzepatide when prescribed for chronic weight management. FDA-approved in November 2023, it contains the same molecule as Mounjaro (approved for type 2 diabetes) but with a distinct brand and indication.
Key facts:
- Generic name: Tirzepatide
- Manufacturer: Eli Lilly
- FDA approval: November 2023 (chronic weight management)
- Administration: Weekly subcutaneous injection
- Doses available: 2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg, 15 mg
Approval Criteria
Zepbound is approved for adults with:
- BMI ≥30 kg/m² (obesity)
- BMI ≥27 kg/m² (overweight) with at least one weight-related condition:
- Hypertension
- Type 2 diabetes
- Dyslipidemia
- Obstructive sleep apnea
- Cardiovascular disease
Clinical Trial Evidence
The SURMOUNT clinical trial program demonstrated exceptional weight loss:
| Trial | Population | Weight Loss (15 mg) |
|---|---|---|
| SURMOUNT-1 | Without T2D | 20.9% vs 3.1% placebo |
| SURMOUNT-2 | With T2D | 14.7% vs 3.2% placebo |
| SURMOUNT-3 | With intensive lifestyle | 24.3% vs 5.0% placebo |
| SURMOUNT-4 | Withdrawal study | Regain after stopping |
These results represent the largest weight reductions observed in any obesity medication trial.
How Zepbound Works
As a dual GIP/GLP-1 receptor agonist, Zepbound works through two pathways:
GLP-1 Receptor Effects:
- Reduces appetite via central nervous system
- Slows gastric emptying
- Promotes satiety signals
GIP Receptor Effects:
- May enhance fat metabolism
- Synergizes with GLP-1 effects
- Potential beta cell benefits
Zepbound vs Wegovy
Head-to-head comparison based on clinical trials:
| Aspect | Zepbound | Wegovy |
|---|---|---|
| Mechanism | Dual GIP/GLP-1 | GLP-1 only |
| Max dose | 15 mg weekly | 2.4 mg weekly |
| Weight loss (trials) | ~21% | ~15% |
| A1C reduction | ~2.1% | ~1.6% |
| Manufacturer | Eli Lilly | Novo Nordisk |
Note: Direct head-to-head trial (SURMOUNT-5) results pending as of early 2026.
Dosing Schedule
| Phase | Dose | Duration |
|---|---|---|
| Starting | 2.5 mg | 4 weeks |
| Escalation 1 | 5 mg | 4 weeks |
| Escalation 2 | 7.5 mg | 4 weeks |
| Escalation 3 | 10 mg | 4 weeks |
| Escalation 4 | 12.5 mg | 4 weeks |
| Maintenance | 15 mg | Ongoing |
Dose escalation can be paused or stopped at any effective dose.
Safety Profile
Side effects are consistent with the incretin class:
Common (over 5%):
- Nausea
- Diarrhea
- Vomiting
- Constipation
- Abdominal pain
Black box warning: Thyroid C-cell tumor risk based on rodent studies.
Special Considerations
- Weight regain: SURMOUNT-4 showed weight regain after discontinuation
- Muscle loss: ~25-40% of weight lost may be lean mass
- Gallbladder: Increased risk of gallbladder-related events
- Pancreatitis: Rare but reported
Regulatory Status
| Region | Status |
|---|---|
| USA (FDA) | Approved (weight management) |
| EU (EMA) | Under review |
| UK (MHRA) | Approved (2024) |
This entry is for educational purposes only. Zepbound is a prescription medication. Consult a healthcare provider for medical advice.
Related Peptides
Related Terms
Disclaimer: This glossary entry is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider for medical questions.