Tirzepatide vs Retatrutide
A detailed comparison to help you understand the differences and choose the right peptide for your research goals.
Tirzepatide
Tirzepatide is a first-in-class dual GIP/GLP-1 receptor agonist. FDA-approved as Mounjaro (diabetes) and Zepbound (weight loss), it has shown superior weight loss results compared to semaglutide in clinical trials.
Full details →Retatrutide
Retatrutide is an investigational triple agonist targeting GIP, GLP-1, and glucagon receptors. Phase 2 trials showed unprecedented weight loss of up to 24% at 48 weeks, making it potentially the most effective obesity treatment studied.
Full details →Side-by-Side Comparison
| Aspect | Tirzepatide | Retatrutide |
|---|---|---|
| Mechanism | Activates both GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 receptors, providing synergistic effects on insulin secretion, appetite suppression, and metabolic regulation. The dual mechanism may explain its enhanced efficacy. | Triple receptor activation provides complementary metabolic effects: GLP-1 and GIP reduce appetite and improve insulin sensitivity, while glucagon receptor activation increases energy expenditure and promotes hepatic fat oxidation. |
| Typical Dosage | Start at 2.5mg weekly, titrate every 4 weeks through 5mg, 7.5mg, 10mg, 12.5mg, to maximum 15mg weekly. Full titration takes approximately 20 weeks. | Clinical trials used doses from 1mg to 12mg weekly. Optimal dosing still being determined in ongoing Phase 3 trials. |
| Administration | Subcutaneous injection once weekly. Rotate injection sites. Slower titration may help reduce GI side effects. | Subcutaneous injection once weekly. Currently only available through clinical trials - not yet FDA approved. |
| Side Effects | Similar to semaglutide: nausea, diarrhea, vomiting, constipation, abdominal pain, decreased appetite. Generally improve with continued use. | Similar GI effects to other incretin-based therapies: nausea, diarrhea, vomiting, constipation. Dose-dependent severity. |
| Best For |
What They Have in Common
Both Tirzepatide and Retatrutide are commonly used for: