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 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 40 YEARS OF IGF1: Insulin like growth factors: actions on the skeleton in: Journal of Molecular Endocrinology Volume 61 Issue 1 (2018) Muscle Building Hormones: The Science of HGH & IGF 1 Thomas DeLauer YouTube What is IGF 1 LR3?, Insulin Like Growth Factor 1 Long R3 (IGF 1 LR3) is a modified version of IGF 1 with a longer half life, making it significantly more potent and effective for muscle growth, INSUGRO DS ( IGF1 DES): Targeted Muscle Growth, Enhanced Fat Burn, and onestop.fit