IGF-1 LR3: Insulin-Like Growth Factor Research in the Laboratory

### IGF axis basics Insulin-like growth factor 1 (IGF-1) mediates growth-hormone–related anabolic signaling. Native IGF-1 binds **IGFBPs** strongly, limiting free fraction and tissue availability in many assays. ### LR3 modification IGF-1 LR3 includes an N-terminal extension and arginine substitution that reduces IGFBP affinity in common experimental designs, extending **functional half-life** in cell culture relative to native IGF-1—why many in vitro protocols reference LR3 analogs. ### Research applications (non-clinical) Typical laboratory uses include **cell proliferation** assays, **myotube** models, and protein-synthesis readouts—always under institutional biosafety and ethics rules. ### RUO Not for human use. For laboratory research only. *IGF-1 LR3 is stocked for research customers requiring documented purity.*