Description
IGF-1 LR3 (Long [Arg3] Insulin-like Growth Factor-1) is a recombinant synthetic analog of human insulin-like growth factor 1, engineered with two structural modifications: an arginine substitution replacing glutamate at position 3 of the IGF-1 sequence (reducing IGFBP-3 binding affinity), and a 13-amino-acid N-terminal extension (Long peptide leader). Together these modifications dramatically reduce binding to IGF-binding proteins (IGFBPs), extending the free fraction half-life from approximately 10-15 minutes for native IGF-1 to roughly 20-30 hours for IGF-1 LR3. The analog retains full IGF-1 receptor (IGF-1R) agonist activity while displaying extended bioactivity in cell culture and rodent research models. IGF-1 LR3 is investigated in preclinical research for IGF-1R signaling, PI3K/Akt/mTOR pathway activation, skeletal muscle protein synthesis, and metabolic pathway research.
Benefits (Research Focus)
• IGF-1 receptor activation — studied for selective high-affinity agonism of the IGF-1 receptor
• PI3K/Akt/mTOR signaling — investigated for downstream activation of cellular growth and protein synthesis pathways
• Reduced IGFBP binding — explored for the Arg3 substitution that decreases IGF-binding protein affinity
• Extended half-life — examined for ~20-30 hour bioactivity window compared to ~15 minutes for native IGF-1
• Skeletal muscle research — researched for satellite cell activation and protein synthesis endpoints in preclinical models
What Researchers Look At
• IGF-1R binding affinity and downstream phosphorylation cascades (IRS-1, Akt, S6K)
• PI3K/Akt/mTOR pathway activation in muscle and metabolic cell models
• IGFBP-3 binding affinity and free fraction pharmacokinetics
• Skeletal muscle protein synthesis and satellite cell activation endpoints
• Comparative bioactivity versus native IGF-1 and other IGF-1 analogs in cell-culture systems
Quick Specs
• Form: Lyophilized white powder
• Net Peptide Content: 1 mg per vial
• Quantity: 1 vial
• Appearance: White to off-white lyophilizate
• Reconstitution: Bacteriostatic or sterile water (added by the end researcher)
• Purity: ≥99% by HPLC
• Identity: MS-verified (per COA)
• Storage: Protect from light
Identity Basics
• Compound: IGF-1 LR3 (Long [Arg3] Insulin-like Growth Factor-1)
• Synonyms: Long R3 IGF-1; LR3 IGF-1; IGF-1 Long R3
• Class: Recombinant IGF-1 analog; IGF-1 receptor (IGF-1R) agonist; 83 amino acids
• Modifications: Arg3 substitution (Glu→Arg at IGF-1 position 3) for reduced IGFBP-3 affinity; 13-residue N-terminal extension (MFPAMPLSSFVNQ) for extended stability
• Formula / M.W.: C400H625N111O115S9, ~9111 g/mol
• CAS: 946870-92-4
⚠️ Disclaimer
This product is intended for laboratory research use only.
Not for human or veterinary use.
Not approved for diagnostic, therapeutic, or medical applications.
Handle using appropriate laboratory safety procedures and personal protective equipment.
COA Verification Notice: Even if the vial label or product image states a certain concentration, always go by the COA for the true verified value. We reference the COA to determine the verified concentration and purity of each product, regardless of what the label or product image indicates.
Janoshik COA — Third-Party Testing
• IGF-1 LR3 VPeptide Canada — October 31, 2025