What is IGF-1 LR3?
IGF-1 LR3 (Insulin-like Growth Factor-1 Long Arg3) is a synthetically modified variant of the naturally occurring IGF-1 peptide. This recombinant peptide belongs to the family of insulin-like growth factors and consists of 83 amino acids, in contrast to native IGF-1 which contains 70 amino acids. The LR3 variant was developed by the substitution of glutamic acid with arginine at position 3, combined with a 13-amino acid N-terminal extension. These structural modifications result in a significantly reduced affinity for IGF-binding proteins (IGFBPs), thereby extending the biological half-life from a few hours to 20-30 hours.
Mechanism of Action
IGF-1 LR3 exerts its biological effects by binding to the IGF-1 receptor (IGF-1R), a transmembrane tyrosine kinase receptor belonging to the insulin receptor family. Upon binding, the receptor undergoes autophosphorylation and activates downstream signal transduction pathways, including the PI3K/Akt pathway and the MAPK cascade. The PI3K/Akt pathway plays a crucial role in cell survival, protein biosynthesis, and glucose metabolism, while the MAPK pathway is involved in cell proliferation and differentiation. Due to its reduced binding to IGFBPs, IGF-1 LR3 remains bioactive longer in the extracellular space, resulting in more prolonged receptor activation compared to wild-type IGF-1. This mechanism facilitates enhanced anabolic processes in various tissue types.
Research Results
Preclinical studies have demonstrated several interesting properties of IGF-1 LR3. In a study with primary myoblast cell cultures, IGF-1 LR3 treatment showed a 3.2-fold increase in protein biosynthesis compared to control groups, measured via [³⁵S]-methionine incorporation. Research in C2C12 myotubes demonstrated that IGF-1 LR3 (100 ng/ml) increased myotube diameter by 28% after 72 hours of treatment. Studies in rat hepatoma cells showed a dose-dependent stimulation of DNA synthesis, with an EC50 value of 2.8 nM. In vivo research in mouse models reported a 15% increase in muscle weight after 14 days of systemic administration. Additional research in diabetic rat models showed improved glucose tolerance and a 23% reduction in fasting glucose levels. These results suggest potential applications in metabolism and tissue regeneration research.
Available Variants and Purity
Dutch Peptide Labs offers IGF-1 LR3 in two research variants: 0.1 mg for €49 and 1 mg for €220. All batches are produced according to pharmaceutical quality standards and achieve a minimum purity of 99.9%, verified by independent HPLC-MS analysis. Each product is supplied with a Certificate of Analysis (CoA) documenting the exact purity, molecular identity, and microbiological safety. The peptide is delivered lyophilized in sterile glass vials under an inert atmosphere to prevent oxidation.
Storage and Handling
Lyophilized IGF-1 LR3 should be stored at -20°C in a dry environment, protected from light. Under these conditions, the peptide remains stable for at least 24 months. For reconstitution, sterile water or saline solution is recommended. After reconstitution, the solution is stable for 7 days at 4°C or up to 30 days at -20°C. Avoid repeated freeze-thaw cycles to minimize peptide degradation. Always use sterile techniques during handling and preparation of solutions.
Research Disclaimer
This product is intended exclusively for scientific research and laboratory use by qualified researchers. IGF-1 LR3 is not approved for human consumption, therapeutic use, or diagnostic purposes. Dutch Peptide Labs disclaims all responsibility for misuse of this product outside the context of scientific research. Users must comply with all relevant safety protocols and local regulations.
