Source comparison
IGF-1 LR3 vs Endogenous IGF-1: Mechanism Comparison
| Factor | Endogenous IGF-1 | IGF-1 LR3 | Professional Assessment ||—|—|—|| Half-life | 12–15 hours | 20–30 hours | Extended half-life allows once-daily dosing and sustained receptor occupancy without multiple administrations || IGFBP binding affinity | High (
This comparison does not assign a generated winner or score.
- | Factor | Endogenous IGF-1 | IGF-1 LR3 | Professional Assessment ||—|—|—|| Half-life | 12–15 hours | 20–30 hours | Extended half-life allows once-daily dosing and sustained receptor occupancy without multiple administrations || IGFBP binding affinity | High (>90% bound in serum) | Low (100–1000× reduced affinity) | Reduced binding protein affinity increases bioavailable IGF-1 that can bind tissue receptors || Receptor specificity | IGF-1R and insulin receptor (IR) | Primarily IGF-1R with minimal IR cross-reactivity | Lower insulin receptor binding reduces hypoglycemia risk compared to endogenous IGF-1 at supraphysiological levels || Tissue selectivity | Systemic (liver-mediated production) | Direct local administration possible | Localized injection protocols (e.g., intramuscular near target tissue) allow higher regional concentrations || Regulatory status | Endogenous hormone | Research peptide (not FDA-approved for human use) | IGF-1 LR3 is available for laboratory research only. No