IGF 1 LR3 does not promote growth in late gestation growth restricted fetal sheep American Journal of Physiology Endocrinology and Metabolism American Physiological Society 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 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 Late life targeting of the IGF 1 receptor improves healthspan and lifespan in female mice Nature Communications