IGF 1 LR3 Before and After: Effects, Timeline and Side Effects Guide 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 Late life targeting of the IGF 1 receptor improves healthspan and lifespan in female mice Nature Communications Longitudinal infusion of a complex of insulin like growth factor I and IGF binding protein 3 in five preterm infants: pharmacokinetics and short term safety Pediatric Research