CAS: 946870-92-4 · MW: ~9111 Da · Purity: ≥99% by reverse-phase HPLC · Format: 1 mg powder · Identity: ESI-MS confirmed
IGF-1 LR3 is a longer-lasting laboratory version of insulin-like growth factor 1, a protein central to growth and tissue signaling. The “LR3” modifications make it more stable and change how it interacts with the proteins that normally bind and limit natural IGF-1, so it stays active longer in an experiment. This is the 1 mg vial, supplied for growth-factor research.
Structure & Identity
IGF-1 LR3 (Long-R3 IGF-1) is an 83-amino-acid recombinant analog of human IGF-1. It carries two key changes: an arginine substitution at position 3 and a 13-residue extension on the N-terminus. Those modifications reduce its binding to IGF-binding proteins and extend its activity, which is the whole point of the analog. Its molecular weight is roughly 9111 Da.
Research Background
IGF-1 LR3 research follows the biology of IGF-1 signaling.
- Long-acting analog. IGF-1 LR3 is a modified IGF-1 that binds IGF-binding proteins less, extending its activity [PMID: 39930003].
- Receptor signaling. IGF-1 signaling regulates growth and metabolic processes [PMID: 39930003].
- Tissue repair. IGF-1’s contribution to tissue repair, such as tendon research, is active [PMID: 40937584].
- Vascular research. Endothelial IGF-1 signalling and vascular barrier function has been studied [PMID: 40171617].
- Foundational biology. The insulin-like growth factors have a long research foundation [PMID: 1307923].
These are research contexts, not approved uses, and the peptide is intended for laboratory study.
Specifications
| Attribute |
Value |
| Chemical name |
IGF-1 LR3 |
| Also Known As |
Long-R3 IGF-1 |
| Modifications |
Arg³ substitution + 13-residue N-terminal extension |
| Length |
83 amino acids |
| CAS number |
946870-92-4 |
| Molecular weight |
~9111 g/mol |
| Purity |
≥99% by reverse-phase HPLC |
| Length |
83 amino acids |
| Identity |
Confirmed by ESI mass spectrometry |
| Physical form |
Lyophilized powder |
| Appearance |
White to off-white solid |
| Quantity |
1 mg per vial |
| Storage |
-20°C, protected from light |
| Solubility |
Soluble in dilute acetic acid or sterile water (gentle mixing) |
| Classification |
Research use only |
Storage & Handling
Keep the sealed vial frozen at -20°C and shielded from light until use. After reconstitution, store the solution at 2-8°C and use it within about two weeks. Because IGF-1 LR3 is a larger, folded protein, gentle reconstitution matters: swirl rather than shake, let it dissolve fully, and avoid repeated freeze-thaw cycles.
Storage and Handling Guide
Quality Assurance
IGF-1 LR3 is produced under research-grade manufacturing controls and verified by an independent lab before release. Purity is measured by reverse-phase HPLC and identity by mass spectrometry, with testing carried out by third-party laboratories, including Janoshik Analytical and domestic US labs. A certificate of analysis is published for each batch, so the results trace to your material.
Quality & Testing
Frequently Asked Questions
What is IGF-1 LR3?
IGF-1 LR3 is a long-acting recombinant analog of insulin-like growth factor 1, an 83-amino-acid protein. It is studied in growth-factor signaling research and is supplied for research use only.
What does “LR3” mean?
“Long-R3” refers to the two modifications: a 13-residue N-terminal extension (“Long”) and an arginine substitution at position 3 (“R3”). Together they extend the analog’s active life.
How is IGF-1 LR3 different from regular IGF-1?
The LR3 modifications reduce its binding to IGF-binding proteins that normally limit IGF-1, so LR3 stays active longer in an experiment than the unmodified protein.
What is IGF-1 LR3’s molecular weight?
It is an 83-amino-acid protein with a molecular weight around 9111 Da and CAS number 946870-92-4.
Is IGF-1 LR3 FDA approved?
No, IGF-1 LR3 is not FDA approved. It is a research-use-only material and is not intended for human or veterinary use.
Why is the vial only 1 mg?
IGF-1 LR3 is a potent, larger protein typically studied at small quantities, so it is offered in a 1 mg vial. The amount refers to the protein content.
How should IGF-1 LR3 be stored?
Keep the powder frozen at -20°C and protected from light. Once reconstituted for research, store at 2-8°C and use within about two weeks.
How is this IGF-1 LR3 verified?
It is tested to ≥99% purity by reverse-phase HPLC with mass-spec identity confirmation by an independent lab, and each batch has a published certificate of analysis.
References
- Regulation and function of insulin and insulin-like growth factor receptor signalling. 2025. PMID: 39930003.
- Contribution of insulin-like growth factor-1 to tendon repair (Review). 2025. PMID: 40937584.
- Insulin-like growth factors. 1992. PMID: 1307923.
