IGF 1: Miracle Hormone or Health Hazard? Diet vs Disease 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 Recombinant Human LR3 IGF I IGF 1 GMP Protein, CF (8335D GMP) by R&D Systems, Part of Bio Techne Gut derived IL 13 contributes to growth via promoting hepatic IGF 1 production Microbiome Springer Nature Link Insulin like growth factor 1 stimulates retinal cell proliferation via activation of multiple signaling pathways ScienceDirect IGF 1: Miracle Hormone or Health Hazard? Diet vs Disease