QK041 Recombinant human bovine porcine IGF 1 LR3 protein 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 Huma Peptide RUO Recombinant Human IGF 1 LR3 Protein Localized Igf 1 transgene expression sustains hypertrophy and regeneration in senescent skeletal muscle Nature Genetics