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 Recombinant Human LR3 Insulin Like Growth Factor I LR3 IGF 1 (MG) Bon Opus Biosciences INSUGRO DS ( IGF1 DES): Targeted Muscle Growth, Enhanced Fat Burn, and onestop.fit Localized Igf 1 transgene expression sustains hypertrophy and regeneration in senescent skeletal muscle Nature Genetics