IGF-1 LR3
A modified version of IGF-1 designed to bind less to its carrier proteins. Mainly used as a reagent in cell-culture media.

Level of evidence
Preclinical — cell and animal studiesWhat it is
IGF-1 LR3 is human IGF-1 (70 amino acids) with arginine in place of glutamic acid at position 3 and a 13-amino-acid extension at the N-terminus. These changes reduce its binding to IGF-binding proteins.
State of the research
It is widely used as a growth supplement in cell-culture media, including for biopharmaceutical production. It has not been developed as a medicine.
Sources
Last reviewed: October 2026
Summaries of published scientific literature, for information and laboratory research only. They do not describe uses of our products, are not medical advice and do not imply that any compound is safe or effective in humans. Our products are not for human or animal consumption.
