Research use only. Not for use in humans or animals. All products and information on this site are provided strictly for in-vitro laboratory research purposes and are supplied as research chemicals only.
What Is IGF-1 LR3? A Research Peptide Overview
IGF-1 LR3 (Long R3 IGF-1) is an engineered analog of insulin-like growth factor 1, widely used as a cell-culture supplement in research laboratories. It is designed to be more stable and less bound by IGF-binding proteins than native IGF-1 in culture. This overview covers what IGF-1 LR3 is, what researchers study it for, and how to verify research-grade material.
IGF-1 LR3 at a glance
| Property | Value |
| --- | --- |
| Name | IGF-1 LR3 (Long R3 IGF-1) |
| Class | Recombinant growth-factor analog |
| Research area | Cell culture, growth-factor signaling (in vitro) |
| Residues | 83-amino-acid analog of IGF-1 |
| Appearance | White lyophilized powder |
| Intended use | Laboratory research only |
Research background
IGF-1 LR3 is a modified IGF-1 in which an arginine replaces a glutamic acid at position 3 and a 13-amino-acid extension is added at the N-terminus. These changes reduce binding to IGF-binding proteins in culture, so the analog remains available to receptors in cell-culture systems for longer than native IGF-1. This makes it a common reagent in laboratories that culture cell lines requiring growth-factor support.
What IGF-1 LR3 is studied for
In laboratory research (cell-culture and non-clinical model systems), IGF-1 LR3 is studied for its role in:
- Cell-culture supplementation — supporting proliferation of cultured cell lines in vitro.
- Growth-factor signaling — IGF-1 receptor pathway research in model systems.
- Comparative studies — as a stable analog reference alongside native IGF-1.
All of this is laboratory research; IGF-1 LR3 offered here is a research chemical only, supplied for in-vitro and non-clinical study.
How research-grade IGF-1 LR3 is verified
Every batch that ships from a credible US supplier should arrive with a third-party Certificate of Analysis (COA) for that exact lot. Peptide Technologies publishes a COA on every batch and ties it to a QR code on the vial. A complete COA reports:
- Identity — mass spectrometry (ESI-MS) confirming the observed mass matches the theoretical mass of the target compound.
- Purity — reverse-phase HPLC, reported as percent peak area (typically at 220 nm). Research-grade material is ≥98–99% by area.
- Net content — gravimetric confirmation the vial holds the stated mass within tolerance.
- Endotoxin — LAL assay below research thresholds, where applicable.
If a vendor cannot show you a lot-specific COA, you cannot verify what is in the vial. Browse the public COA library →
How to source research-grade material
For laboratory research, sourcing quality comes down to a few checks:
- Lot-specific COA from an accredited, independent laboratory — not a generic marketing PDF.
- HPLC purity ≥98% by peak area, with the chromatogram shown.
- US synthesis and finishing, so the chain of custody is documented end to end.
- Cold-chain shipping for lyophilized material, so the product arrives stable.
Peptide Technologies meets each of these and shows the live competitor price on every product page. See how our pricing compares →
FAQ
What is IGF-1 LR3?
IGF-1 LR3 is a long-arg3 analog of insulin-like growth factor 1 used as a cell-culture research reagent. It is supplied as a research chemical for laboratory use only.
How does IGF-1 LR3 differ from native IGF-1?
IGF-1 LR3 carries an Arg substitution at position 3 and an N-terminal extension, which reduce binding to IGF-binding proteins in culture. This keeps it available to receptors in cell-culture systems longer than native IGF-1.
Is IGF-1 LR3 legal to buy for research?
IGF-1 LR3 is sold by Peptide Technologies for laboratory research use only (RUO). It is not an approved drug, dietary supplement, cosmetic, or food. Buyers must affirm research use and accept the Terms of Sale at checkout. Not for use in humans or animals.
Is IGF-1 LR3 FDA approved?
No. IGF-1 LR3 is not approved by the FDA and is not intended to diagnose, mitigate, or prevent any condition. It is supplied strictly as a research chemical for laboratory use only.
How is IGF-1 LR3 verified?
Research-grade IGF-1 LR3 is verified by RP-HPLC for purity, by mass spectrometry for identity, and — where applicable — by an LAL endotoxin assay, all reported on a lot-specific third-party Certificate of Analysis.
Where can I buy IGF-1 LR3 for research?
You can buy IGF-1 LR3 online directly from Peptide Technologies at peptidetech.is, with a third-party COA, cold-chain shipping, and lot traceability on every batch. View the IGF-1 LR3 product page →