Description
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].
- Connective-tissue signaling. IGF-1’s role in connective-tissue cell signaling 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. For research use, keep prepared solutions at 2-8°C and study within about two weeks. Because IGF-1 LR3 is a larger, folded protein, handle it gently, keep it cold, and limit freeze-thaw cycles.
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.
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.
