IGF-1 LR3 Compound Reference
Published · Last updated · Publisher: ENOS Labs USA
What is IGF-1 LR3?
IGF-1 LR3 is an engineered analog of insulin-like growth factor I with a 13 residue N terminal extension and arginine at position 3. Those changes reduce binding to IGF binding proteins, which is why it was developed as a cell culture and animal research reagent. It is not an approved drug for any use.
- Synonyms
- Long R3 IGF-I; LR3-IGF-1
- Classification
- Recombinant analog of insulin-like growth factor I with an extension peptide and an arginine substitution
What is IGF-1 LR3?
Long R3 IGF-I was designed in Australia in the early 1990s as a more potent IGF-I variant for research and cell culture.
Research context
Work includes animal growth and metabolism studies and its routine use as a cell culture supplement. Anti doping laboratories have also characterized it in seized products.
Mechanisms being investigated
- IGF-1 receptor activation with reduced sequestration by IGF binding proteins.
Research status
Approval status: Not approved for human use. Highest evidence tier in the cited literature: preclinical.
Not approved. It is a research reagent, distinct from the approved IGF-I drug mecasermin.
Established findings
- Reduced binding protein affinity and increased potency in animal and cell models.
Preliminary or experimental findings
- Any effect in humans, which has not been studied in controlled trials.
Chemical reference information
No PubChem record with verified formula and weight was found for this material, so none is shown.
Testing considerations
- Recombinant protein of about 83 residues: mass spectrometry should confirm the intact mass and absence of tags.
- A published anti doping case found a His tagged research grade variant in a vial, so tag status is worth checking.
General methods are explained in purity versus identity testing.
What is still unknown
- Human pharmacology and safety.
Related resources
ENOS catalog listing: IGF-1 LR3 1MG
Research use limitations
This page summarizes published research and regulatory status. It is not medical advice and does not describe any use in people. Material supplied by ENOS Labs USA is for in-vitro laboratory research only and is not a drug product, even where a related drug has been approved.
To continue, see recovery and performance research, how to read a certificate of analysis, why purity and identity are separate tests, the compound directory and the peptide testing glossary.
References
Each source below was opened and checked against its PubMed, ClinicalTrials.gov or PubChem record. Links open in a new tab.
- Design and characterisation of long-R3-insulin-like growth factor-I muteins which show resistance to pepsin digestion (PMID 8919033)Growth Factors, 1996 · PubMed
- Insulin-like growth factor-I and more potent variants restore growth of diabetic rats without inducing all characteristic insulin effects (PMID 7683875)The Biochemical Journal, 1993 · PubMed
- Detection of His-tagged Long-R3-IGF-I in a black market product (PMID 20675162)Growth Hormone & IGF Research, 2010 · PubMed
These products are sold strictly for in-vitro laboratory research and are not intended for human consumption, diagnosis, treatment, or any therapeutic use. Purchaser must be 18 years of age or older and confirms they are a qualified researcher.