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 QK041 Recombinant human bovine porcine IGF 1 LR3 protein Explanation, Benefits, and Dosing for IGF LR3 Wittmer Rejuvenation Clinic IGF 1 LR3 1mg Peptide: Growth Factor Research 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,