IGF 1 LR3 The Muscle Building Peptide Everyone's Talking About IGF 1 LR3 is one of the most powerful performance peptides used for muscle growth, recovery, and fat loss. It's a modified version IGF 1 LR3 Injection Benefits And How It Works The HCG Institute IGF1 stimulates greater muscle hypertrophy in the absence of myostatin in male mice in: Journal of Endocrinology Volume 234 Issue 2 (2017) IGF 1 LR3 100mcg 1mg Peptide Bulk Supply