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 | 8 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 8 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. TRIUMPH-2 (type 2 diabetes, 20.8% at 80 weeks) was published in The Lancet in September 2026; the other Phase 3 figures remain topline. Lilly plans to submit to the FDA in Q1 2027.
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.