IGF 1 LR3 does not promote growth in late gestation growth restricted fetal sheep American Journal of Physiology Endocrinology and Metabolism American Physiological Society What is IGF 1 LR3?, Insulin Like Growth Factor 1 Long R3 (IGF 1 LR3) is a modified version of IGF 1 with a longer half life, making it significantly more potent and effective for muscle growth, Recombinant Human LR3 IGF I IGF 1 GMP Protein, CF 8335D GMP: R&D Systems Modulatory activity of testosterone on growth pattern and IGF 1 levels in vanishing testis syndrome: a case report during 15 years of follow up BMC Endocrine Disorders Springer Nature Link IGF 1: Miracle Hormone or Health Hazard? Diet vs Disease