IGF 1 LR3 for Female Athletes: Safe Use and Lean Gains How to take Long R3 IGF 1 to get optimal muscle gains the science, the receptors, the strategy that got me to go from 289lb to 309 (20lbs) in 20 days! If you like this clip, check out the full Attenuated glucose stimulated insulin secretion during an acute IGF 1 LR3 infusion into fetal sheep does not persist in isolated islets Journal of Developmental Origins of Health and Disease Cambridge Core IGF 1 LR3 does not promote growth in late gestation growth restricted fetal sheep American Journal of Physiology Endocrinology and Metabolism American Physiological Society