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 IGF 1 LR3 vs HGH: Which Growth Enhancer Is Better? Swolverine Recombinant human IGF 1 LR3 protein (Qk041) 100 Cell proliferation bioactivity of purified IGF 1 LR3 IGF 1. (A) Download Scientific Diagram