IGF-1 LR3
Research Use Only · Not for Human Consumption
A modified analog of human Insulin-like Growth Factor-1 with a 13-amino-acid N-terminal extension and an arginine substitution at position 3
A modified IGF-1 analog with a 13-amino-acid N-terminal extension and Arg-3 substitution
Chemistry
| CAS# | Formula | Molar Mass |
|---|---|---|
| CAS Number: 946870-92-4 | Molecular Formula: C400H625N111O115S9 | Molar Mass: 9117.6 g/mol |
What is IGF-1 LR3?
IGF-1 LR3 (Insulin-like Growth Factor-1 Long R3) is a recombinant analog of human IGF-1. The 'Long' refers to a 13-amino-acid extension at the N-terminus, and 'R3' indicates an arginine substitution at position 3, a modification that reduces affinity for IGF-binding proteins in preclinical research models. Supplied in lyophilized form.
IGF-1 LR3 emerged from research efforts in the late 1980s and early 1990s to create modified versions of insulin-like growth factor with altered binding profiles. Scientists at GroPep in Adelaide, Australia, were among the first to develop this modified peptide, characterizing it in the context of native IGF-1's rapid sequestration by circulating binding proteins.
The key structural change was twofold: adding 13 extra amino acids to the N-terminus of the peptide sequence and substituting arginine for glutamic acid at position 3. These modifications reduced affinity for IGF-binding proteins (IGFBPs) in preclinical assays, yielding a research-grade analog with a longer apparent half-life in in-vitro and animal models than native IGF-1.
Since its development, IGF-1 LR3 has appeared in peer-reviewed preclinical publications examining IGF-1 receptor signaling in cell culture and animal models. Its reduced IGFBP affinity makes it a common tool compound for investigating IGF-1R-mediated pathways in research settings. This product is intended for research use only.
How should IGF-1 LR3 be stored?
Peptide Foundry research peptides are supplied lyophilized (freeze-dried). Keep sealed vials cool, dry, and protected from light until reconstitution.
After reconstitution, refrigerate prepared solutions and use sterile technique. For general laboratory diluent and handling notes, see lyophilized peptide reconstitution.
Certificate of Analysis
All IGF-1 LR3 batches are independently tested by a third-party laboratory for purity and identity verification via HPLC with UV detection coupled with Mass Spectrometry.
HPLC Purity
98.509%
Product
IGF-1 LR3 — 1mg
Lot Number
IG312
Appearance
White Lyophilized Powder
Measured Net Content
1.32 mg
Test Method
HPLC-UV / Mass Spectrometry
Report Date
03/15/2026
COA Number
2603130190
Laboratory
Freedom Diagnostics
No Certificate of Analysis is available for the selected size yet. Contact support for batch-specific documentation.
COA documents are updated with each new batch. Contact support for batch-specific documentation.
Related Research Compounds
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Further reading
References
- Francis GL, et al. Novel recombinant fusion protein analogues of insulin-like growth factor (IGF)-I indicate the relative importance of IGF-binding protein and receptor binding for enhanced biological potency. Journal of Molecular Endocrinology. 1992;8(3):213-223. PubMed: 1378742
- Tomas FM, et al. Insulin-like growth factor-I (IGF-I) and especially IGF-I variants are anabolic in dexamethasone-treated rats. Biochemical Journal. 1992;282(Pt 1):91-97. PubMed: 1371669
- Ballard FJ, et al. Does IGF-I ever act through the insulin receptor? Cytokine & Growth Factor Reviews. 2007;18(1-2):7-12.
