Understanding GLP-1 Medications
Tirzepatide and semaglutide are both GLP-1 receptor agonists used for weight management and type 2 diabetes. While they share similarities, there are key differences that may make one more suitable than the other for different individuals.
Mechanism of Action
Semaglutide (Ozempic/Wegovy)
Semaglutide is a single-action GLP-1 receptor agonist. It mimics the GLP-1 hormone, which:
- Slows gastric emptying
- Increases feelings of fullness
- Reduces appetite
- Improves blood sugar control
Tirzepatide (Mounjaro/Zepbound)
Tirzepatide is a dual-action GIP/GLP-1 receptor agonist. It activates both:
- GLP-1 receptors (same as semaglutide)
- GIP (glucose-dependent insulinotropic polypeptide) receptors
This dual mechanism may provide enhanced metabolic benefits.
Weight Loss Comparison
| Medication | Average Weight Loss | Study Duration |
|---|---|---|
| Semaglutide 2.4mg | ~15-17% | 68 weeks |
| Tirzepatide 15mg | ~20-22% | 72 weeks |
Clinical studies suggest tirzepatide may produce greater weight loss on average, though individual results vary significantly.
Dosing Schedules
Semaglutide Titration
- Week 1-4: 0.25mg weekly
- Week 5-8: 0.5mg weekly
- Week 9-12: 1.0mg weekly
- Week 13-16: 1.7mg weekly
- Week 17+: 2.4mg weekly (maintenance)
Tirzepatide Titration
- Week 1-4: 2.5mg weekly
- Week 5-8: 5mg weekly
- Week 9-12: 7.5mg weekly
- Week 13-16: 10mg weekly
- Week 17-20: 12.5mg weekly
- Week 21+: 15mg weekly (maintenance)
Side Effects Comparison
Both medications share similar side effects, primarily gastrointestinal:
- Nausea (most common)
- Vomiting
- Diarrhea
- Constipation
- Abdominal pain
Side effects are typically most pronounced during dose increases and often diminish over time.
Key Differences Summary
| Factor | Semaglutide | Tirzepatide |
|---|---|---|
| Mechanism | GLP-1 only | GLP-1 + GIP dual |
| Max dose | 2.4mg/week | 15mg/week |
| Avg weight loss | 15-17% | 20-22% |
| FDA approved | 2021 | 2023 |
Which Should You Choose?
The choice between tirzepatide and semaglutide should be made with a healthcare provider based on:
- Your specific health conditions
- Previous medication responses
- Insurance coverage and cost considerations
- Individual weight loss goals
Use our Peptide Calculator to help with dosing calculations for either medication.