What does "LR3" actually mean?

"L" for the 13-amino-acid N-terminal extension (MFPAMPLSSLFVN), "R" for arginine, and "3" for position 3 of the IGF-1 sequence. So "LR3" literally means "the Long variant with an Arginine at position 3". Both modifications are needed to eliminate IGFBP binding and extend circulating half-life.

How is IGF-1 LR3 different from IGF-1 DES?

IGF-1 DES is the opposite end of the design spectrum - a truncated 67-residue form missing the N-terminal tripeptide GPE, which also dramatically reduces IGFBP binding. IGF-1 LR3 uses a 13-residue extension to achieve similar IGFBP resistance. LR3 has a much longer half-life (20-30 h vs minutes); DES produces more intense, shorter-duration local effects when injected site-specifically.

Why is IGF-1 LR3 used in cell culture?

Native IGF-1 is inefficient in cell culture because IGFBPs produced by the cells themselves can sequester it, reducing effective concentrations. IGF-1 LR3 escapes that sequestration and delivers consistent, reproducible growth-factor signalling. That is why it is an industry standard for bioprocessing and mammalian cell culture.

How should IGF-1 LR3 be stored?

Keep the lyophilised powder frozen at −20 °C. After reconstitution with bacteriostatic water, refrigerate at 1-6 °C and protect from light. IGF-1 LR3 is a structured protein and is sensitive to repeated freeze-thaw cycles - aliquot if you need multiple doses from one reconstitution.

Lyophilised · batch-documented · discreet packaging

Research peptide

IGF-1 LR3

Name: IGF-1 LR3
Brand: New-U Research Peptides
SKU: igf-1-lr3
Availability: InStock

Insulin-like Growth Factor-1 Long Arg3 - Extended Half-Life Growth Factor

IGF-1 LR3 is a modified version of IGF-1 (Insulin-Like Growth Factor-1), one of the most powerful growth signals in your body. It has been engineered with two structural changes that extend its active life from just 20 minutes (natural IGF-1) to 20–30 hours, making it one of the longest-acting growth factor peptides available for research.

>99% (HPLC) HPLC purity

9111.4 Da mol. weight

Lyophilised Powder Presentation

EU·US·UK Ship regions

Third-party tested

Every batch independently verified by Janoshik & Freedom Diagnostics for purity and identity.

Full COA included

Certificate of Analysis confirms peptide purity, amino acid composition, and absence of contaminants.

Discreet shipping

Every order ships in plain, unmarked packaging with full tracking. No external branding or product details visible.

Research-grade

Uniform vial presentation, consistent labeling, and batch-level documentation every time.

10-vial pack

View Certificate of Analysis COA

Janoshik & Freedom Diagnostics verified
Certificate of analysis per batch
Direct-from-manufacturer sourcing
Discreet, unmarked packaging

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Research use only. All compounds are sold strictly for in-vitro research and educational purposes. Not approved for human use, therapeutic application, or as food or cosmetic products. By purchasing, you agree to use these products only for legitimate research purposes.

IGF-1 LR3

Third-party tested

Full COA included

Discreet shipping

Research-grade

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IGF-1 LR3 Research & Reconstitution Guides

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IGF-1 LR3 Research Guide

IGF-1 LR3 - Plain-English Guide

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How to Store Peptides

Research Resources