IGF 1 LR3 does not promote growth in late gestation growth restricted fetal sheep American Journal of Physiology Endocrinology and Metabolism American Physiological Society Theres a lot of confusion around peptides and muscle., Heres how I actually think about it., Most peptides dont build muscle directly., They improve the systems that allow muscle to grow., First, Normalized steady state total IGF IR complex concentration when free Download Scientific Diagram IGF 1 DES: Dosage, Benefits, and Comparison with IGF 1 LR3 i313