Retatrutide vs tirzepatide calculator
Compare projected weight loss outcomes between retatrutide (triple agonist) and tirzepatide (dual agonist) based on Phase 3 and SURMOUNT-1 trial data. Enter your weight and target loss percentage.
Retatrutide
Triple agonistProjected weight loss (20%)
44.0 lbs
Target weight: 176.0 lbs
Based on Phase 3 trial data (80 weeks, 2,339 patients)
Tirzepatide
Dual agonistProjected weight loss (~18%)
38.7 lbs
Target weight: 181.3 lbs
Based on SURMOUNT-1 trial data (72 weeks)
Head-to-head comparison
| Metric | Retatrutide | Tirzepatide |
|---|---|---|
| Weight loss (Phase 3) | ★25% | 22% |
| Weight loss (lowest dose) | ★18% at 4mg | 15% at 5mg |
| Mechanism | ★GIP + GLP-1 + Glucagon (triple) | GIP + GLP-1 (dual) |
| Trial duration | 80 weeks | 72 weeks |
| Patients in Phase 3 | 2,339 | 2,539 |
| No weight plateau at 2yr | ★Yes | No |
| Fatty liver clearance | ★86% | Not studied |
| Ketone body elevation | ★2–3× increase | Minimal |
| Tingling/numbness SE | 12.5% | ★Not reported |
| FDA approval status | Filing late 2026 | ★Approved (Zepbound) |
| Half-life | ~6 days | ~5 days |
| Dosing frequency | Once weekly | Once weekly |
★ indicates advantage based on published trial data. Retatrutide not yet FDA approved — for research use only.
Research use only. This calculator is provided for educational and research purposes only. It does not constitute medical advice. Consult a licensed physician before use.
References
Jastreboff AM, Kaplan LM, Frías JP, et al. (2023). Triple–Hormone-Receptor Agonist Retatrutide for Obesity — A Phase 2 Trial. New England Journal of Medicine. DOI: 10.1056/NEJMoa2301972
Jastreboff AM, Aronne LJ, Ahmad NN, et al. (2022). Tirzepatide once weekly for the treatment of obesity (SURMOUNT-1). New England Journal of Medicine. DOI: 10.1056/NEJMoa2206038