What is IGF-1 LR3? Receptor-model note

> Research-use notice: This article is educational laboratory context only. It is not medical advice. No dosing, administration, or human-use guidance is provided. BlueNex Labs research-use-only products are not intended for human or veterinary use.

IGF-1 LR3 (long arginine-3 insulin-like growth factor-1) is a synthetic analog of IGF-1. Relative to mature IGF-1, the version discussed in laboratory papers replaces a residue near the N-terminus with arginine and adds a short extension, which lowers affinity for IGF-binding proteins. Cell-culture groups use it when they want a more persistent IGF-1 receptor signal in serum-free media. There is no IGF-1 LR3 shop SKU on this site. This page does not offer a vial, a price, or a certificate.

Structure

Research descriptions usually stress:

• An IGF-1 backbone, not an incretin sequence and not a growth-hormone secretagogue

• The arginine substitution and N-terminal extension that define the LR3 analog in the literature

• Reduced binding to IGF-binding proteins compared with unmodified IGF-1, which is why the analog is used in some culture systems

• No lot identity, milligram size, or stock status on this website

Do not treat a CJC-1295, Ipamorelin, or other catalog certificate as documentation for IGF-1 LR3.

Mechanisms discussed in research settings

Papers place IGF-1 LR3 in:

• IGF-1 receptor phosphorylation and downstream kinase assays

• Serum-free cell-culture systems where binding-protein sequestration would otherwise limit the ligand

• Comparisons with insulin and with unmodified IGF-1, which are different ligands

• The muscle-biology literature summarized in Peptides in muscle-biology lab models, beside other sequences that are not this analog

Receptor activation in culture is not a human-use protocol. What is Follistatin-344? Activin-binding note describes a binding protein in a different pathway. What is AOD-9604? hGH-fragment research describes a growth-hormone fragment, also unlisted.

What this guide is not

It is not a catalog page. A primer on how short peptides are discussed as messengers is How do peptides work? Canada primer. Stocked metabolic materials are indexed under Metabolic Research Peptides, Canada.

RUO

Research-use only. Not for human or veterinary use. No administration guidance is provided.