IGF-1 LR3 Research Guide: The Engineered Growth Factor

IGF-1 LR3 solves a practical research problem. Native IGF-1 is heavily bound by six carrier proteins (IGFBPs) that regulate its availability — in culture systems, that binding devours your added growth factor before it reaches a receptor.

The engineering

Long-R3-IGF-1 adds a 13-amino-acid N-terminal extension and swaps glutamic acid for arginine at position 3. The changes gut IGFBP affinity while preserving IGF-1 receptor activity — more free ligand at equivalent dosing, which is why cell-culture protocols overwhelmingly specify LR3 rather than native IGF-1.

Research context

IGF-1 signalling (PI3K/Akt and MAPK cascades) is foundational to growth, metabolism and ageing research. LR3 is the standard tool for activating it cleanly in vitro — media supplementation in cell-line work is its biggest literature by volume.

Handling

As a 83-residue protein it is more fragile than small peptides: gentle handling, no vortexing, strict cold chain. ≥99% verification and batch documentation are non-negotiable at this complexity.

Volume buyers and peptide businesses can source wholesale stock, tested in Australia, through our trade and white-label program.

All compounds discussed are for in-vitro laboratory research only and are not for human or veterinary use.