IGF-1 LR3 (Insulin-like Growth Factor-1 Long R3) is one of the most potent anabolic growth factors available for research. This modified version of native IGF-1 features an amino acid substitution and extension that dramatically extends its half-life — making it an essential tool for studying muscle cell proliferation, tissue growth, and the GH/IGF-1 axis in laboratory settings.
What is IGF-1 LR3?
IGF-1 LR3 is a recombinant analog of human insulin-like growth factor-1 (IGF-1) with two key modifications: an Arginine substitution at position 3 (R3) and a 13-amino acid extension peptide at the N-terminus. These modifications reduce binding to IGF-binding proteins (IGFBPs) and extend the half-life from approximately 12 minutes (native IGF-1) to roughly 20-30 hours — a transformational improvement for research applications.
Mechanism of Action
- IGF-1 Receptor Activation: Binds to type 1 IGF receptors (IGF-1R) on target cells, activating the PI3K/Akt and MAPK signaling cascades
- Reduced IGFBP Binding: The R3 modification decreases binding to inhibitory IGF-binding proteins, increasing free (bioactive) IGF-1
- Extended Half-Life: The 13-amino acid extension prevents rapid clearance, providing sustained receptor activation
IGF-1 LR3 vs. Native IGF-1
Native IGF-1 has a plasma half-life of only 12 minutes, making it impractical for most research protocols. IGF-1 LR3's 20-30 hour half-life provides sustained activity, more consistent research conditions, and more practical dosing schedules. Additionally, reduced IGFBP binding means more of the peptide remains biologically active.
Research Applications
Muscle Cell Research
IGF-1 is one of the most potent myogenic factors identified. Research demonstrates that IGF-1 stimulates myoblast proliferation, satellite cell activation, and myotube hypertrophy. IGF-1 LR3 allows researchers to study these effects under sustained receptor activation conditions.
GH/IGF-1 Axis Studies
IGF-1 is the primary mediator of growth hormone's anabolic effects. Research using IGF-1 LR3 examines the relationship between GH stimulation, hepatic IGF-1 production, and downstream tissue effects — including feedback mechanisms where IGF-1 modulates GH secretion.
Neuroprotection Research
IGF-1 has neuroprotective properties, promoting neuronal survival, synapse formation, and myelination. IGF-1 LR3 is used in neuroscience research to study these effects under sustained exposure conditions.
Available Formulations
AltPeptide offers IGF-1 LR3 in two research-grade dosages: 0.1mg (for preliminary studies) and 1mg (standard research protocols).
Conclusion
IGF-1 LR3's extended half-life and reduced binding protein affinity make it far superior to native IGF-1 for research applications. From muscle cell proliferation to neuroprotection, it provides researchers with a sustained-activity growth factor for studying tissue growth, repair, and the GH/IGF-1 axis.
Source Research-Grade IGF-1LR3
AltPeptide offers IGF-1LR3 in multiple research-grade formulations. All products are third-party assayed, lyophilized for stability, and shipped with DDP worldwide delivery.
All compounds are sold for laboratory research purposes only. Not for human or animal consumption.
All compounds mentioned are sold for in-vitro laboratory research only. Not for human or animal consumption. Not approved by FDA or any regulator for therapeutic use. This article is for educational and informational purposes only.