IGF 1 LR3 Dosage: What to Know About Dosing, Safety, and Clinical Use 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: Miracle Hormone or Health Hazard? Diet vs Disease IGF 1 LR3 Injection Benefits And How It Works The HCG Institute