IGF-1 LR3

IGF-1 LR3 has been studied primarily in fetal sheep models, where infusion increased organ-specific growth (heart, kidney, spleen, adrenal glands) and skeletal muscle myoblast proliferation without increasing overall muscle mass or protein synthetic rate. Studies also show it reduces circulating insulin and glucose-stimulated insulin secretion, suggesting potential metabolic disruption with prolonged use. A 2025 study found it did not improve growth in growth-restricted fetuses, and a nerve conduit study showed enhanced peripheral nerve regeneration with controlled IGF-1 LR3 release. Human clinical data for bodybuilding or performance applications is essentially absent; most evidence is preclinical or animal-based.