Retatrutide vs Liraglutide
Side-by-Side Comparison
| Attribute | Retatrutide | Liraglutide |
|---|---|---|
| Category | Metabolic / Triple Agonist | Metabolic / GLP-1 Agonist |
| Mechanism | Retatrutide simultaneously activates three receptors: GLP-1 (reduces appetite, slows gastric emptying, improves insulin secretion), GIP (enhances insulin sensitivity, glucose control), and glucagon... | Liraglutide binds to GLP-1 receptors on pancreatic β-cells, increasing intracellular cAMP and triggering glucose-dependent insulin secretion. |
| Evidence Rating | B — Phase III / NDA Filed | A — FDA Approved |
| Clinical Status | Phase 3 clinical trials (Eli Lilly TRIUMPH program) | FDA-approved (Victoza for T2D, Saxenda for obesity) |
| Safety Profile | GI side effects (dose-related, 13-63% across dose groups): nausea, vomiting, diarrhea, constipation; mostly mild to moderate; GI events partially mitigated with lower starting dose (2 mg vs 4 mg initial dose) | Common: nausea (39%), diarrhea (21%), constipation (19%), vomiting (15%), headache (13%); GI side effects are dose-dependent and typically diminish over weeks |
| Route | Subcutaneous (clinical trial formulation only) | Subcutaneous |
| Dose Range | Phase 2 tested 1, 4, 8, 12 mg weekly SC; optimal dose being determined in Phase 3 | Saxenda: 0.6-3.0 mg/day; Victoza: 0.6-1.8 mg/day |
| Frequency | Once weekly | Once daily |
| Molecular Weight | N/A | ~3,751 g/mol |
| Half-Life | ~6 days (allows once-weekly dosing) | ~13 hours |
Overview
Retatrutide and Liraglutide are both research peptides studied across multiple applications. This comparison examines their mechanisms, evidence base, dosing protocols, and safety profiles to help researchers understand the key differences and overlaps.
Retatrutide — Mechanism & Evidence
Retatrutide is a first-in-class investigational triple hormone receptor agonist (GIP, GLP-1, and glucagon) developed by Eli Lilly. In the Phase 2 trial (Jastreboff et al., NEJM 2023, n=338), the 12 mg dose achieved 24.2% mean body weight reduction at 48 weeks, with 100% of participants achieving at least 5% weight loss. Multiple Phase 3 TRIUMPH trials are ongoing, with TRIUMPH-4 (Dec 2025) reporting average loss up to 71.2 lbs with osteoarthritis pain relief. Expected FDA approval is 2027-2028.
Key claims: Unprecedented weight loss in Phase 2; Phase 3 confirms efficacy with osteoarthritis benefit; Improves glycemic control in type 2 diabetes.
Liraglutide — Mechanism & Evidence
Liraglutide is an FDA-approved GLP-1 receptor agonist with 97% amino acid sequence homology to endogenous human GLP-1. Developed by Novo Nordisk, it is approved as Victoza for type 2 diabetes and Saxenda for chronic weight management. It was the first GLP-1 agonist approved for obesity. While effective, it has been largely superseded by semaglutide (once-weekly dosing, greater weight loss) — liraglutide requires daily injection and achieves approximately 8% weight loss vs semaglutide's 15%.
Key claims: Clinically significant weight loss; Improves glycemic control; Cardiovascular benefit.
Shared Research Applications
Both peptides are studied for: Weight Management, Metabolic Health.
Retatrutide is also researched for: no additional unique applications.
Liraglutide is also researched for: Cardiovascular.
Safety Considerations
Retatrutide: GI side effects (dose-related, 13-63% across dose groups): nausea, vomiting, diarrhea, constipation; mostly mild to moderate GI events partially mitigated with lower starting dose (2 mg vs 4 mg initial dose) Dose-dependent heart rate increases peaking at 24 weeks, declining thereafter
Liraglutide: Common: nausea (39%), diarrhea (21%), constipation (19%), vomiting (15%), headache (13%) GI side effects are dose-dependent and typically diminish over weeks FDA black box warning for thyroid C-cell tumors (rodent data)
Related Products
Retatrutide 20mg
20mg
Retatrutide 10mg
10mg
Related Research News
Retatrutide Clinical Trial Results: Phase III TRIUMPH Data Shows Significant Weight Loss
Early reports from the Phase III TRIUMPH-1 trial suggest retatrutide, a novel triple agonist, has delivered substantial weight loss outcomes. These retatrutide clinical trial results indicate a potential shift in obesity treatment research, though full data analysis is pending.
Retatrutide Phase III TRIUMPH-1 Results: Unprecedented Weight Loss Reported at ADA26
Early reports from the American Diabetes Association 2026 meeting suggest retatrutide delivered unprecedented weight loss in the Phase III TRIUMPH-1 trial. Researchers and industry professionals are closely watching these retatrutide clinical trial results for implications in obesity and metabolic disease treatment.
Retatrutide Monthly Research Cost in Australia Breakdown
Researching Retatrutide (LY3437943), the most advanced triple GLP-1/GIP/glucagon receptor agonist, involves costs that vary by vial size, dose, and frequency. In Australia, a 10mg vial costs $129.99 AUD ($13.00/mg), while a 20mg vial is $199.99 AUD ($10.00/mg). Supplies like bacteriostatic water and needles add to monthly expenses, with planning around a 4-week reconstituted stability window essential to minimize waste.