Purity > 95%, MW: 8.3 kDa. Human insulin-like growth factor-1 Long R3(IGF-1 LR3) are produced with the animal component free bioreactor. IGF-1 LR3(Long Arg3 IGF-1) is an 83 amino acid analog of IGF-1 comprising the complete human IGF-1 sequence with the substitution of an Arg for the Glu at positon 3(hence R3), and a 13 amino acid extension peptide at the N-terminus. The LR3 IGF has much higher stability and biological activity. Compared with IGF-1, IGF-1 LR3 has 13 more amino acids, greatly increasing the structural stability of the polypeptide and maintaining the same effect. Its biological activity is 10 times that of IGF-1,200-1000 times higher than insulin, which can reach 1*106 Units/mg.