What is IGF-1 LR3?
IGF-1 LR3 is a modified form of insulin-like growth factor 1 with one amino-acid change and a 13-amino-acid extension.
How does IGF-1 LR3 work?
The changes stop it from binding the proteins that normally inactivate IGF-1, so it stays active much longer.
What are researchers studying?
- ●Cell-culture growth media in labs
- ●Muscle-cell growth signaling
- ●IGF-1 receptor biology
Where does the evidence stand?
Mainly used as a laboratory reagent. Not approved by the FDA for any use. Prohibited in sport by WADA.
Quick facts
- Research area
- Growth Factors
- Also known as
- IGF1 LR3, IGF-1LR3
- Third-party lab results
- 3 published COAs →
- Tested vendors tracking it
- 1 vendor →
Recent peer-reviewed research
The most relevant IGF-1 LR3 studies from the last three years, via PubMed (U.S. National Library of Medicine).
- IGF-1 LR3 does not promote growth in late-gestation growth-restricted fetal sheepAmerican journal of physiology. Endocrinology and metabolism · 2025 Jan 1 · PubMed ↗
- Intranasal long R3 insulin-like growth factor-1 treatment promotes amyloid plaque remodeling in cerebral cortex but fails to preserve cognitive function in male 5XFAD miceJournal of Alzheimer's disease : JAD · 2025 Jan · PubMed ↗
- The emerging landscape of performance-enhancing peptides modulating GH-IGF1 axis: bridging the gap between clinical evidence and patient self-administrationFrontiers in endocrinology · 2026 · PubMed ↗
- Revolutionary decellularized Alstroemeria stem-based nerve conduit integrated with GelMA and controlled IGF-1 LR3 release for enhanced rat sciatic nerve regenerationInternational journal of biological macromolecules · 2025 Nov · PubMed ↗
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This guide summarizes published research for educational purposes only. It is not medical advice and does not describe how to use IGF-1 LR3. Citations link to PubMed and are listed for reference — we haven't reviewed or endorsed their findings. Products referenced on The Peptide Audit are sold by third parties for laboratory research use only and are not for human consumption.