Recombinant expression of IGF 1 and LR3 IGF 1 fused with xylanase in Pichia pastoris Applied Microbiology and Biotechnology Springer Nature Link IGF 1 LR3 The Muscle Building Peptide Everyone's Talking About IGF 1 LR3 is one of the most powerful performance peptides used for muscle growth, recovery, and fat loss. It's a modified version IGF 1LR3 IGF 1, the Cross Road of the Nutritional, Inflammatory and Hormonal Pathways to Frailty Insulin Like Growth Factor 1 (IGF 1) and Its Monitoring in Medical Diagnostic and in Sports