Dulaglutide vs Retatrutide
A neutral, side-by-side comparison of two glp-1 & metabolic peptides — their mechanisms, dosing ranges, administration routes, side effects, and research evidence. For research and educational purposes only.
Dulaglutide
Once-weekly GLP-1 receptor agonist (Trulicity) approved for type 2 diabetes and cardiovascular risk reduction. Engineered as a GLP-1 analogue fused to a modified IgG4-Fc domain, which provides a ~5-day half-life and enables once-weekly subcutaneous dosing via a simple auto-injector pen with no reconstitution required.
Full profileRetatrutide
Retatrutide (LY3437943) is Eli Lilly's investigational once-weekly triple agonist of the GIP, GLP-1, and glucagon receptors. Phase 2 data showed 24.2% mean weight loss at 48 weeks; the Phase 3 TRIUMPH program has since reported topline weight loss approaching 28–30% — among the largest reductions recorded for any obesity pharmacotherapy. It is not yet FDA-approved.
Full profile| Dulaglutide | Retatrutide | |
|---|---|---|
| Category | GLP-1 & Metabolic | GLP-1 & Metabolic |
| Also known as | Trulicity, LY2189265 | LY3437943, Triple G, GIP/GLP-1/Glucagon Receptor Agonist |
| Evidence | FDA-approved | Investigational (in trials) |
| Dosing range | 0.75mg–4.5mg mg, once weekly subcutaneous | 2mg–12mg mg, once weekly |
| Administration | Subcutaneous injection (auto-injector pen) | Subcutaneous injection (weekly) |
| Key side effects | Nausea (most common), Diarrhea, Vomiting, Abdominal pain | Nausea (most common, dose-dependent), Vomiting, Diarrhea, Constipation |
| Cited sources | 2 references | 6 references |
Key differences
- Evidence level differs: Dulaglutide is fda-approved, while Retatrutide is investigational (in trials).
- Administration: Dulaglutide — Subcutaneous injection (auto-injector pen); Retatrutide — Subcutaneous injection (weekly).
- Frequency: Dulaglutide is typically once weekly subcutaneous; Retatrutide is once weekly.
- Research depth: this profile cites 2 sources for Dulaglutide vs 6 for Retatrutide.
How each works
Dulaglutide
Dulaglutide's large molecular structure (fusion with IgG4-Fc) prevents renal filtration and extends half-life via FcRn recycling, enabling once-weekly dosing. The REWIND cardiovascular outcomes trial demonstrated significant reduction in major adverse cardiovascular events (MACE) in patients with or at risk for cardiovascular disease, establishing dulaglutide as a cardioprotective agent beyond glucose control.
Retatrutide
Across the Phase 2 trial (NEJM 2023, Jastreboff et al.) and the Phase 3 TRIUMPH registrational program (TRIUMPH-1 through -4), retatrutide has produced dose-dependent weight loss reaching ~28.3% at 80 weeks (TRIUMPH-1, 12 mg) and ~28.7% at 68 weeks in a knee-osteoarthritis population (TRIUMPH-4, 12 mg), alongside improvements in glycemia, blood pressure, lipids, and liver fat. The glucagon component is thought to add energy expenditure on top of the appetite suppression driven by GLP-1 and GIP. As of mid-2026, Phase 3 efficacy figures are topline (press-release/conference level) and not yet published in full peer-reviewed form.
This comparison aggregates public research and structured profile data for informational purposes only. It is not medical advice and does not recommend either compound for human use. Consult a qualified healthcare provider before considering any peptide.