IGF-LR3 – 1mg

Researchers who buy IGF-1 LR3 research peptide are typically studying its behavior as a synthetic 83-amino-acid analog of human insulin-like growth factor 1 (IGF-1), modified to reduce binding to IGF-binding proteins (IGFBPs) while preserving IGF-1-receptor agonist activity. The summary below reflects the published preclinical literature and is provided strictly for research and educational reference — it does not describe an intended effect of this product in humans or animals.

In this reference:

• What Is IGF-1 LR3?
• Proposed Mechanism of Action
• Chemical Identity
• Purity, Storage & Quality
• Research Applications
• What the Human Evidence Shows
• Frequently Asked Questions

What Is IGF-1 LR3?

IGF-1 LR3 (Long-R3-IGF-1) is a synthetic 83-amino-acid analog of human insulin-like growth factor 1 (IGF-1), engineered with two structural modifications relative to native IGF-1: a glutamic-acid-to-arginine substitution at position 3, and a 13-amino-acid extension appended to the N-terminus. Published research characterizing this and related recombinant IGF-1 fusion-protein analogs examined how these modifications affect the relative importance of IGF-binding-protein interaction versus IGF-1-receptor binding for biological potency, reporting that the engineered analog retains IGF-1-receptor agonist activity while showing markedly reduced affinity for IGF-binding proteins relative to native IGF-1.

Researchers sourcing this compound are typically studying IGF-1-receptor pharmacology under conditions where reduced IGFBP sequestration is a relevant experimental variable — for example, in vitro assay systems where native IGF-1’s rapid binding-protein sequestration complicates interpretation of receptor-mediated effects.

Proposed Mechanism of Action

IGF-1 LR3 is studied as an agonist at the IGF-1 receptor (IGF-1R), a receptor tyrosine kinase that, upon ligand binding, activates downstream signaling including the PI3K/Akt pathway — a signaling cascade extensively studied in cell-growth, protein-synthesis, and metabolic-research contexts. Because native circulating IGF-1 is substantially sequestered by IGF-binding proteins (IGFBPs) in physiological conditions, its effective receptor engagement in some experimental systems can be limited by binding-protein availability rather than IGF-1R expression alone. Published research on IGF-1 LR3’s structural modifications was specifically designed to probe this relationship, and reported that engineered variants with reduced IGFBP affinity showed altered biological potency relative to native IGF-1 in the assay systems tested — supporting the general principle that binding-protein interaction meaningfully modulates IGF-1 receptor-pathway signaling.

Separate published research examining IGF-1 versus Long-R3-IGF-1 in bovine embryo culture reported that the two ligands differently affected embryo development and the expression of mRNA for IGF-binding proteins and type I IGF receptors in that in vitro system (Mol Reprod Dev. 2001 Feb;58(2):143-53; PMID 11181549), providing a directly comparative research reference for how the LR3 modification changes measured biological activity relative to native IGF-1 in a controlled in vitro system.

Chemical Identity

Structural Basis	83-aa IGF-1 analog (Glu3→Arg + 13-aa N-terminal extension)
Molecular Formula	C400H625N111O115S9
Molecular Weight	~9111.6 g/mol
Appearance	White to off-white lyophilized powder

Purity, Storage & Quality

First Class Science supplies this IGF-1 LR3 research peptide vial at research-grade purity, verified by independent third-party HPLC testing and mass spectrometry. A Certificate of Analysis is available for every batch at our Certificate of Analysis page, listing the specific lot’s purity result, molecular-weight confirmation, and test date.

Store the lyophilized (freeze-dried) compound at −20°C for long-term stability. This vial must be reconstituted with bacteriostatic or sterile water before laboratory use; after reconstitution, refrigerate at 2–8°C and use within 4–6 weeks. Avoid repeated freeze-thaw cycles and prolonged exposure to light or room-temperature conditions, both of which are associated with accelerated peptide degradation in handling literature.

Important: This item is manufactured strictly for research purposes. It is not intended for human or veterinary use and is distributed solely for laboratory and scientific investigation.

Preparing Solutions for Laboratory Use

Laboratories reconstituting lyophilized IGF-1 LR3 for in vitro research typically follow standard peptide-handling practice: the vial is brought to room temperature before opening, and a diluent — commonly reconstitution solution, sterile water for injection (SWFI), or a dilute acidic buffer suited to this protein’s solubility profile — is added slowly down the interior wall of the vial rather than directly onto the lyophilized material, to reduce foaming and mechanical stress. The vial is then gently swirled, never shaken, until fully dissolved.

Stock-solution concentration for a given protocol is calculated by dividing the total peptide mass in the vial by the volume of diluent added, and that calculation should be recorded in the study’s protocol documentation. This page describes general laboratory reconstitution practice for research use and is not a dosing guide for human or animal administration.

Quality Control Methodology

Each production batch of this IGF-1 LR3 research peptide undergoes independent third-party testing before release. High-performance liquid chromatography (HPLC) confirms purity by measuring the proportion of the target peptide relative to synthesis by-products or degradation fragments. Mass spectrometry separately confirms molecular identity, verifying that the measured mass of the material matches the expected ~9111.6 g/mol molecular weight of IGF-1 LR3. Both results are recorded on the batch’s published Certificate of Analysis, letting researchers independently verify identity and purity rather than relying on manufacturer claims alone.

Who Should Buy IGF-1 LR3 Research Peptide

Researchers who buy IGF-1 LR3 from First Class Science are typically university and academic laboratories, contract research organizations (CROs), and biotechnology R&D teams running in vitro cell-culture studies on IGF-1-receptor signaling, IGF-binding-protein interactions, or PI3K/Akt pathway research. First Class Science requires that all research-peptide orders be placed by parties who acknowledge and agree to the research-use-only terms stated on this page prior to purchase.

Research Applications

The published literature on IGF-1 LR3 spans a handful of distinct research areas. Each is summarized below strictly as a description of what has been studied in in vitro or animal models — not as a claim about effects for any individual using this product.

IGF-Binding-Protein Interaction Research

The engineering rationale for IGF-1 LR3’s structural modifications was to probe how IGFBP interaction versus direct IGF-1-receptor binding contributes to biological potency, published in foundational recombinant-IGF-analog characterization research. This remains the primary research application cited for the compound.

Comparative In Vitro Cell-Culture Research

Controlled in vitro comparisons of native IGF-1 versus Long-R3-IGF-1 have examined differential effects on cell/embryo development and IGF-binding-protein and receptor mRNA expression in cultured systems (PMID 11181549), providing a directly comparative reference for how the LR3 modification alters measured biological activity relative to unmodified IGF-1.

IGF-1 Receptor Signaling Pathway Research

As an IGF-1R agonist, IGF-1 LR3 is used in broader in vitro research examining downstream IGF-1-receptor signaling, including PI3K/Akt pathway activation, in cell-culture systems where researchers wish to minimize IGFBP-mediated confounding of ligand availability.

What the Human Evidence Shows

Researchers evaluating IGF-1 LR3 should know that no controlled human clinical trial of IGF-1 LR3 itself has been published in the peer-reviewed literature as of this writing. The published evidence base for this compound consists of in vitro cell-culture and comparative-binding-assay research, and animal-model studies examining IGF-1-receptor pathway pharmacology. IGF-1 LR3 is not an FDA-approved drug for any indication, has not entered a published human clinical-trial pathway, and is not evaluated by the FDA for safety or efficacy in humans or animals.

Researchers should characterize IGF-1 LR3 findings accordingly in any grant application or protocol design — as in vitro and animal-model evidence, not as clinical safety or efficacy data. As controlled human research is published, if any, this page will be updated to reflect it.

Frequently Asked Questions

What is the purity of this IGF-1 LR3 research peptide?
Every batch is independently verified via third-party HPLC and mass-spectrometry testing, with a Certificate of Analysis published for each lot.

How should IGF-1 LR3 research peptide be stored?
Store the lyophilized powder at −20°C. After reconstitution, refrigerate at 2–8°C and use within 4–6 weeks; avoid repeated freeze-thaw cycles.

Is IGF-1 LR3 approved for human or animal use?
No. IGF-1 LR3 is not an FDA-approved drug for any indication and has not entered a published human clinical-trial pathway. It is sold exclusively for in vitro and laboratory research use.

Has IGF-1 LR3 been tested in humans at all?
Not as of this writing. The published evidence base for IGF-1 LR3 is limited to in vitro and animal-model research. No controlled human trial has been published.

How does IGF-1 LR3 differ from native IGF-1?
IGF-1 LR3 carries a glutamic-acid-to-arginine substitution at position 3 and a 13-amino-acid N-terminal extension relative to native IGF-1. Published research reports these modifications reduce affinity for IGF-binding proteins while preserving IGF-1-receptor agonist activity, altering the compound’s biological potency profile relative to native IGF-1 in tested systems.

What does the Certificate of Analysis show?
The Certificate of Analysis published for each batch shows the HPLC purity result, mass-spectrometry molecular-weight confirmation, lot number, and test date, allowing researchers to independently verify the identity and purity of the specific batch they receive.

Can IGF-1 LR3 research peptide be shipped internationally?
Shipping availability and any import restrictions for research peptides vary by destination country and are subject to change; researchers should confirm their local import regulations for research-use-only compounds before ordering.

Shipping, Handling & Compliance

This IGF-1 LR3 research peptide ships as a lyophilized powder in a sealed glass vial, packaged to maintain cold-chain integrity in transit where applicable. All orders are subject to the research-use-only terms stated on this page, and First Class Science does not sell this or any other research peptide for human or veterinary administration under any circumstance.

Order tracking, batch-specific documentation requests, and general product questions can be directed to First Class Science customer support, which can confirm current lead times and any destination-specific documentation a receiving institution may require for its own compliance records.

Disclaimer: The research summarized above is drawn from third-party published studies conducted in animal or in vitro contexts. It is provided for research and educational reference only and does not describe an intended use, effect, or benefit of this product for any person or animal.

⊗ ALL ITEMS ARE SOLD FOR RESEARCH USE ONLY. This category covers strictly in vitro laboratory testing and scientific experimentation. Content on this site is for education only and does not authorize human or animal use of any kind, which is prohibited by law. Only trained, licensed professionals should handle these materials. Nothing sold here qualifies as a drug, food, or cosmetic, and none of it may be labeled, advertised, or used as such.