IGF-LR3
A modified insulin-like growth factor 1 analog engineered for extended activity in tissue-growth research.
Overview
IGF-LR3 is a modified analog of insulin-like growth factor 1 (IGF-1), engineered with an added 13-amino-acid extension and a substituted arginine at position 3 (hence “LR3”). These modifications reduce its binding to IGF-binding proteins, which in native IGF-1 quickly deactivate the hormone — giving IGF-LR3 a substantially longer active half-life in research settings.
Mechanism of Action
Like native IGF-1, IGF-LR3 binds the IGF-1 receptor, activating downstream signaling (including the PI3K/Akt and MAPK pathways) involved in cell growth, proliferation, and survival. Its research value comes from its resistance to IGF-binding proteins, allowing researchers to study sustained IGF-1-receptor activation without the rapid clearance seen with native IGF-1.
Cited Research
IGF-1 receptor signaling
Well-characterized activation of PI3K/Akt and MAPK pathways via the IGF-1 receptor.
Binding-protein resistance
Documents the structural modifications that extend IGF-LR3’s active half-life relative to native IGF-1.
Muscle hypertrophy research
Studied for effects on satellite cell proliferation and muscle tissue growth signaling.
This is a summary, not an exhaustive review. Search the primary literature yourself: IGF-LR3 on PubMed →
Safety & Handling
IGF-LR3 should be handled only by qualified personnel in a laboratory setting, stored and reconstituted per its Certificate of Analysis, and kept refrigerated once reconstituted. It is not evaluated or approved by the FDA for any human or veterinary use.
Frequently Asked Questions
Is IGF-LR3 the same as growth hormone?
No — growth hormone acts upstream in the liver to stimulate IGF-1 production. IGF-LR3 is a modified version of IGF-1 itself, acting directly on the IGF-1 receptor.
Is IGF-LR3 legal to purchase?
It’s legal to sell and purchase as a research chemical for laboratory use in the U.S. It is not approved by the FDA as a drug or supplement for human consumption.
How should it be stored?
Keep the lyophilized powder refrigerated or frozen prior to reconstitution. Once reconstituted, keep refrigerated and use within the timeframe on its Certificate of Analysis.
Is this page medical advice?
No. This page summarizes published literature for research and educational context only. It does not recommend a dose, protocol, or use in humans or animals outside a laboratory setting.
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