What is IGF 1 LR3? LIVV Can I take Insulin like Growth Factor 1 Long R3 (IGF 1LR3) with Type 1 Diabetes Mellitus (T1DM)? What is the effect of Insulin like Growth Factor 1 (IGF 1) Long Arg3 (LR3) on muscle growth? IGF 1 LR3 is a powerful growth factor that helps build muscle, burn fat, and speed up recovery. It works by boosting protein synthesis, which helps muscles grow and heal faster. It also improves how IGF 1 LR3 does not promote growth in late gestation growth restricted fetal sheep American Journal of Physiology Endocrinology and Metabolism American Physiological Society IGF 1, the Cross Road of the Nutritional, Inflammatory and Hormonal Pathways to Frailty