Introduction: The First Triple-Agonist Peptide
GLP-3 R (LY3437943) represents a groundbreaking advancement in metabolic peptide research. As the first triple-agonist peptide targeting GIP, GLP-1, and glucagon receptors simultaneously, it has generated extraordinary scientific interest since its initial characterization.
This guide covers everything researchers need to know about GLP-3 R’s molecular design, mechanism, published findings, and laboratory handling.
Molecular Profile
- Development name: LY3437943
- Classification: Triple GIP/GLP-1/glucagon receptor agonist
- Amino acids: 39
- Structure: GIP-based backbone with engineered GLP-1 and glucagon receptor affinity
- Half-life: ~6 days in research models (supports weekly administration)
- Receptor targets: GIP receptor, GLP-1 receptor, Glucagon receptor
Why Triple Agonism Matters
Previous incretin-based peptide research has explored:
- Single agonists (e.g., semaglutide — GLP-1 only)
- Dual agonists (e.g., GLP-2 T — GIP + GLP-1)
GLP-3 R adds a third target — the glucagon receptor — which introduces an entirely new metabolic dimension. Glucagon receptor activation is associated with increased energy expenditure, hepatic lipid metabolism, and thermogenesis, creating a mechanism profile unlike any previous peptide.
Mechanism of Action: Three Pathways
1. GLP-1 Receptor Activation
Like semaglutide, GLP-3 R activates GLP-1 receptors to promote insulin secretion, suppress glucagon release, and slow gastric emptying. This pathway is the most well-characterized of the three.
2. GIP Receptor Activation
Similar to GLP-2 T, GLP-3 R engages GIP receptors, which enhance insulin sensitivity and may improve lipid metabolism. The GIP component is thought to complement and amplify GLP-1 effects.
3. Glucagon Receptor Activation (Novel)
The glucagon receptor component is what makes GLP-3 R unique. Glucagon activation drives:
- Increased energy expenditure via thermogenesis
- Hepatic fat oxidation — breaking down liver fat stores
- Amino acid metabolism changes
- Ketogenesis stimulation
This triple combination creates a metabolic profile that simultaneously addresses glucose regulation, appetite signaling, and energy expenditure — three pillars that single or dual agonists can only partially engage.
Published Research Highlights
Phase 2 Clinical Trial (2023)
The landmark Phase 2 study published in the New England Journal of Medicine demonstrated GLP-3 R’s unprecedented research outcomes:
- Dose-dependent metabolic effects across all three receptor pathways
- Greater magnitude of body weight reduction than any previously studied single molecule
- Up to 24.2% mean body weight reduction at the highest dose over 48 weeks
- Significant improvements in glycemic parameters
- Notable effects on hepatic fat content
Ongoing Research Programs
Multiple Phase 3 trials are currently underway examining GLP-3 R’s effects across various metabolic conditions, including the TRIUMPH program studying long-term outcomes.
GLP-3 R vs Other Metabolic Peptides
| Feature | Semaglutide | GLP-2 T | GLP-3 R |
|---|---|---|---|
| Receptor Targets | GLP-1 | GIP + GLP-1 | GIP + GLP-1 + Glucagon |
| Generation | 1st gen incretin | 2nd gen (dual) | 3rd gen (triple) |
| Energy Expenditure | Minimal direct effect | Moderate | Strong (via glucagon) |
| Liver Fat Research | Some data | Promising data | Strong early data |
| Research Maturity | Fully characterized | Well characterized | Emerging (Phase 3) |
| Half-Life | ~7 days | ~5 days | ~6 days |
For a detailed comparison of semaglutide and GLP-2 T specifically, see our Semaglutide vs GLP-2 T Guide.
Research Applications
GLP-3 R is being studied across multiple research domains:
- Metabolic syndrome modeling — simultaneous glucose/lipid/weight pathway research
- Hepatic steatosis (fatty liver) research — glucagon-driven fat oxidation
- Energy expenditure studies — thermogenic effects via glucagon receptor
- Comparative incretin research — benchmarking triple vs dual vs single agonism
- Cardiovascular metabolic research — lipid profile and inflammatory marker effects
Storage and Handling
- Lyophilized: Store at -20°C, protect from light and moisture
- Reconstituted: 2-8°C, use within recommended stability window
- Reconstitution solvent: Bacteriostatic water
- Handling: Avoid repeated freeze-thaw, use aseptic technique
For complete protocols, see our Reconstitution Guide and Storage Guide.
Source Research-Grade GLP-3 R
Proxiva Labs supplies GLP-3 R at >99.99% verified purity in 10mg and 20mg vials. Every batch includes third-party testing with full certificates of analysis.
Browse our complete research peptide catalog.
Disclaimer: All compounds are intended strictly for laboratory research and in-vitro use only. Not for human consumption.
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