What Is IGF-1 LR3? A Research Primer
IGF-1 LR3 is a synthetic 83-amino-acid analog of insulin-like growth factor 1. Sold for laboratory research use only.
IGF-1 LR3 (Long R3 IGF-1) is an 83-amino-acid analog of insulin-like growth factor 1. It carries an arginine substitution at position 3 and a 13-amino-acid N-terminal extension, modifications that reduce its binding to IGF binding proteins. It is sold as a research-use-only reference compound.
What makes IGF-1 LR3 distinct
The Arg3 substitution and N-terminal extension distinguish it structurally from native IGF-1 (70 amino acids) and from IGF-1 DES. It is an IGF-1 analog itself, not a secretagogue peptide, which places it in a different class from the GHRH analogs and ghrelin-receptor agonists.
Research-use status
- Pharmacological class: insulin-like growth factor 1 analog
- Published literature is mostly animal and cell work
- Sold for laboratory research use only; this page does not summarise effects or uses
COA and verification considerations
Because research compounds are unregulated, the certificate of analysis is the single most important thing to check. For IGF-1 LR3, a trustworthy COA names the testing laboratory, reports HPLC purity (typically 99% or higher), confirms identity by mass spectrometry, and, for injectable-format material, includes endotoxin and sterility results. A batch or lot number that matches the product, a recent test date, and a working verification portal are strong positive signals.
What to check before buying
- Is a named third-party lab shown, not just a claim of testing?
- Does the COA lot number match the batch you are buying, with a recent date?
- Are purity and identity both reported, ideally with endotoxin and sterility?
- How does the vendor rank on our published, testing-led formula?
Frequently Asked Questions
How is IGF-1 LR3 different from regular IGF-1?
It has an Arg3 substitution and a 13-amino-acid N-terminal extension that reduce its binding to IGF binding proteins, which is the structural difference from native IGF-1.
What should an IGF-1 LR3 COA include?
A named third-party lab with HPLC purity and mass-spec identity confirmation. IGF-1 LR3 is an 83-residue protein, so verify the reported sequence and molecular weight match.
Does an affiliate deal affect its ranking?
No. Vendor position is set only by our published methodology.