The signaling landscape of insulin like growth factor 1 ScienceDirect 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 1 infusion to fetal sheep increases organ growth but not by stimulating nutrient transfer to the fetus American Journal of Physiology Endocrinology and Metabolism American Physiological Society Activation of insulin like growth factor 1 receptor (IGF 1R) promotes growth of colorectal cancer through triggering the MEX3A mediated degradation of RIG I ScienceDirect Frontiers Sheep recombinant IGF 1 promotes organ specific growth in fetal sheep