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: Miracle Hormone or Health Hazard? Diet vs Disease QK041 Recombinant human bovine porcine IGF 1 LR3 protein Activation of IGF 1 pathway and suppression of atrophy related genes are involved in Epimedium extract (icariin) promoted C2C12 myotube hypertrophy Scientific Reports