IGF-1 LR3

IGF-1 LR3 (Long R3 Insulin-like Growth Factor-1) is a recombinant analogue of human IGF-1 featuring two critical modifications: a glutamic acid to arginine substitution at position 3 (E3R) and a 13-amino acid N-terminal extension peptide. These modifications dramatically reduce binding affinity for IGF-binding proteins (IGFBPs), resulting in approximately 2-3 times greater biological potency and a significantly extended functional half-life compared to native IGF-1. IGF-1 LR3 signals through the IGF-1 receptor (IGF-1R), activating the PI3K/Akt and MAPK/ERK signaling cascades that drive cell proliferation, differentiation, and survival. It is widely used in cell culture research as a media supplement to promote cell growth in serum-free or reduced-serum conditions. Research applications extend to studies on muscle hypertrophy signaling, satellite cell activation, neuronal differentiation, chondrocyte proliferation, and cancer cell biology. The enhanced bioavailability of LR3 relative to native IGF-1 makes it particularly valuable for in-vitro studies where consistent, sustained growth factor exposure is required.