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? LIVV IGF 1 LR3 (Insulin like Growth Factor 1 Long R3) is often called the "Holy Grail" of muscle building peptides because of its potent anabolic effects. In a Med Spa context, it is typically sought out Insulin like growth factor 1 in articular cartilage repair for osteoarthritis treatment Arthritis Research & Therapy Springer Nature Link