IGF 1: Miracle Hormone or Health Hazard? Diet vs Disease IGF 1 LR3 tells your muscle cells to grow, repair, and absorb nutrients better. It works directly at the muscle level to help you build lean muscle and recover faster.What it is IGF 1 IGF 1 LR3: 1 mg Supernova Peptides Recombinant expression of IGF 1 and LR3 IGF 1 fused with xylanase in Pichia pastoris Applied Microbiology and Biotechnology Springer Nature Link