IGF-1 LR3 (Long R3 Insulin-Like Growth Factor 1) is an 83-amino acid recombinant analog of human IGF-1. The modification includes a 13-amino acid N-terminal extension peptide and the substitution of arginine for glutamic acid at position 3 of the mature IGF-1 sequence. These structural changes result in markedly reduced binding affinity to IGF-binding proteins (IGFBPs), increasing the bioavailability and half-life of the peptide in experimental systems. In preclinical laboratory research, IGF-1 LR3 is utilized to study IGF-1 receptor (IGF-1R) mediated signaling, including downstream Akt/PI3K and MAPK/ERK pathway activation. Researchers employ this analog in cell culture and animal model systems to investigate proliferative, anti-apoptotic, and metabolic signaling responses independent of IGFBP sequestration. Published experimental literature describes its use in studying myoblast differentiation, satellite cell proliferation, and glucose uptake dynamics in skeletal muscle and adipose biology models. Molecular Weight: ~9,111 Da CAS: 946870-92-4 This product is intended for in-vitro and in-vivo laboratory research exclusively. Not for human consumption.