IGF-1 LR3

• Long R3 IGF-1 is a modified analogue of human IGF-1.
• It has 83 amino acids — 13 more than native IGF-1 — and an arginine at position 3 in place of glutamic acid.
• Both modifications are associated in the literature with a markedly longer biological half-life than the native molecule.
• It is not a peptide in the sense of a short chain, but a growth factor.

• It acts on the IGF-1R receptor; published work describes activation of the PI3K/Akt and MAPK pathways.
• According to the literature, the substitution at position 3 reduces binding to the IGFBP binding proteins, which changes the availability of the molecule.
• In models, an effect on cell proliferation and differentiation is described.

• IGF-1R signalling and its downstream pathways.
• Cell proliferation and growth in tissue culture.
• Glucose metabolism — IGF-1 has partial affinity for the insulin receptor.

Most of the data comes from in vitro models and cell cultures, where the LR3

variant is used precisely for its stability. Controlled clinical studies in

humans for this modified form are not available.

IGF-1 and its analogues are growth factors with pronounced biological activity

and appear on the Prohibited List of the World Anti-Doping Agency (WADA).

This item is a **reference standard intended strictly for laboratory and

research use**. It is not a medicine and must not be used for administration to

humans or animals. We provide no dosing or health advice.