© 2026 Aureon Bioscience
IGF-1LR3
$120.00
Skip to product information
IGF-1LR3
Overview
IGF-1 LR3 (Long Arginine 3-Insulin-like Growth Factor 1) is a synthetic, 83-amino acid analog of human IGF-1, modified with an arginine substitution at position 3 and a 13-amino acid N-terminal extension. These structural modifications dramatically reduce its binding affinity to IGF-binding proteins (IGFBPs), particularly IGFBP-3, increasing its bioavailability and extending its half-life. IGF-1 LR3 is approximately three times more potent than native IGF-1 and is used in research investigating cellular growth, anabolic signaling, metabolic regulation, and tissue regeneration.
Mechanism of Action
IGF-1 LR3 binds to and activates the IGF-1 receptor (IGF-1R), triggering downstream signaling cascades including the PI3K/Akt/mTOR pathway, which promotes protein synthesis and cell survival, and the MAPK pathway, which stimulates cellular proliferation and differentiation. By evading rapid binding to IGFBPs, it remains biologically active in circulation significantly longer than endogenous IGF-1.
Research and Off-Label Applications
Investigated for skeletal muscle growth, repair, and satellite cell activation, fat metabolism and body recomposition, tissue regeneration and recovery, glucose metabolism and insulin sensitivity, and neurological and anti-aging research.
Administration
Administered via subcutaneous injection. Research cycles typically range from 4–6 weeks. IGF-1 LR3 is not FDA-approved for any indication.
Potential Adverse Effects
Potential concerns include effects on glucose metabolism and insulin sensitivity, risk of cellular proliferation in individuals with existing malignancies, and joint or soft tissue swelling. Long-term safety data in humans is limited.
Pharmacokinetics
Half-life: approximately 20–30 hours, compared to 12–15 hours for native IGF-1.
Properties
1. Basic Information
2. Structural Properties Peptide Nature: Single-chain 83-amino acid peptide retaining the four-domain structure of native IGF-1 (B, C, A, D domains) with an additional 13-amino acid N-terminal extension and Glu3Arg substitution; three intramolecular disulfide bonds preserved from native IGF-1 structure
Secondary Structure: Retains the globular fold of native IGF-1 comprising two α-helical regions and a β-sheet within the core domain; N-terminal extension is largely unstructured and contributes to reduced IGFBP affinity
Hydrophobicity: Moderately hydrophobic core consistent with native IGF-1; overall hydrophilic surface profile supports aqueous solubility
Charge: Net positive charge at physiological pH; arginine substitution at position 3 contributes additional positive charge relative to native IGF-1
3. Solubility
4. Stability Thermal Stability: Sensitive to elevated temperatures; activity loss accelerates above 37°C; disulfide bonds susceptible to reduction under strongly reducing conditions
Proteolytic Stability: N-terminal extension and Glu3Arg substitution substantially reduce binding affinity to IGFBPs (particularly IGFBP-3), extending effective plasma half-life to approximately 20–30 hours compared to 12–15 hours for native IGF-1; susceptible to insulin-degrading enzyme (IDE) and other endopeptidases
Storage: Store lyophilized at −20°C or −80°C for long-term stability; reconstituted solution stable up to 7–14 days at 2–8°C; avoid repeated freeze-thaw cycles; addition of carrier protein extends reconstituted stability
5. Chemical Reactivity Three intramolecular disulfide bonds (Cys6–Cys48, Cys18–Cys61, Cys47–Cys52 in native IGF-1 numbering) are essential for maintaining bioactive globular conformation; reducing agents such as DTT or TCEP abolish receptor binding activity
Glu3Arg substitution introduces a positively charged residue at the IGFBP-binding interface, sterically and electrostatically disrupting IGFBP-3 and IGFBP-5 interactions
Methionine residues present; susceptible to oxidation under peroxide-containing or prolonged aerobic conditions; protect from oxidative environments during storage and handling
Peptide backbone stable at mildly acidic to neutral pH; hydrolysis risk increases under alkaline conditions
6. Other Properties
- Name: IGF-1 LR3 (Long Arginine 3–Insulin-like Growth Factor 1)
- Type: Synthetic long-acting IGF-1 analog peptide
- Length: 83 amino acids
- Sequence: 13-amino acid N-terminal extension followed by native IGF-1 sequence with glutamate-to-arginine substitution at position 3
- Molecular Weight: ~9,117 Da
- Formula: C₃₉₀H₆₂₅N₁₁₁O₁₁₅S₉
2. Structural Properties Peptide Nature: Single-chain 83-amino acid peptide retaining the four-domain structure of native IGF-1 (B, C, A, D domains) with an additional 13-amino acid N-terminal extension and Glu3Arg substitution; three intramolecular disulfide bonds preserved from native IGF-1 structure
Secondary Structure: Retains the globular fold of native IGF-1 comprising two α-helical regions and a β-sheet within the core domain; N-terminal extension is largely unstructured and contributes to reduced IGFBP affinity
Hydrophobicity: Moderately hydrophobic core consistent with native IGF-1; overall hydrophilic surface profile supports aqueous solubility
Charge: Net positive charge at physiological pH; arginine substitution at position 3 contributes additional positive charge relative to native IGF-1
3. Solubility
- Soluble in sterile water and dilute acetic acid (0.1%); optimal reconstitution at acidic to neutral pH
- Supplied as lyophilized white powder; recommended reconstitution in 0.1% acetic acid or bacteriostatic water
- Protein carrier such as 0.1% BSA may be added to prevent adsorption to container surfaces at low concentrations
4. Stability Thermal Stability: Sensitive to elevated temperatures; activity loss accelerates above 37°C; disulfide bonds susceptible to reduction under strongly reducing conditions
Proteolytic Stability: N-terminal extension and Glu3Arg substitution substantially reduce binding affinity to IGFBPs (particularly IGFBP-3), extending effective plasma half-life to approximately 20–30 hours compared to 12–15 hours for native IGF-1; susceptible to insulin-degrading enzyme (IDE) and other endopeptidases
Storage: Store lyophilized at −20°C or −80°C for long-term stability; reconstituted solution stable up to 7–14 days at 2–8°C; avoid repeated freeze-thaw cycles; addition of carrier protein extends reconstituted stability
5. Chemical Reactivity Three intramolecular disulfide bonds (Cys6–Cys48, Cys18–Cys61, Cys47–Cys52 in native IGF-1 numbering) are essential for maintaining bioactive globular conformation; reducing agents such as DTT or TCEP abolish receptor binding activity
Glu3Arg substitution introduces a positively charged residue at the IGFBP-binding interface, sterically and electrostatically disrupting IGFBP-3 and IGFBP-5 interactions
Methionine residues present; susceptible to oxidation under peroxide-containing or prolonged aerobic conditions; protect from oxidative environments during storage and handling
Peptide backbone stable at mildly acidic to neutral pH; hydrolysis risk increases under alkaline conditions
6. Other Properties
- Extended half-life: Approximately 20–30 hours versus 12–15 hours for native IGF-1, attributable to reduced IGFBP binding rather than protease resistance
- Potency: Reported as approximately 2–3 times more potent than native IGF-1 in cell-based proliferation assays due to sustained receptor availability
- Receptor selectivity: Retains full IGF-1R binding affinity; reduced affinity for insulin receptor relative to insulin, consistent with native IGF-1 selectivity profile
- Research classification: Not approved for human use by any regulatory authority; classified strictly as a research reagent; widely used in cell culture and preclinical animal research as a tool compound
Description
IGF-1 LR3 is a synthetic research peptide and has been described in the scientific literature as a long-acting analog of insulin-like growth factor 1 (IGF-1), incorporating an arginine substitution at position 3 and a 13-amino acid N-terminal extension. Publications referencing IGF-1 LR3 discuss it in the context of IGF-1 receptor pharmacology, anabolic signaling cascades, and binding protein interaction dynamics within experimental systems.
Reports involving IGF-1 LR3 describe its receptor binding characteristics and downstream signaling properties under defined experimental conditions. Observations of IGF-1 receptor activation, PI3K/Akt/mTOR and MAPK pathway components, and reduced IGF-binding protein (IGFBP) affinity are limited to non-clinical research settings and are reported as descriptive findings within cellular and animal model studies.
All references to IGF-1 LR3 are confined to mechanistic and observational research contexts and do not extend beyond laboratory-based investigation.
In the scientific literature, IGF-1 LR3 has been referenced in non-clinical research involving receptor binding assays, cell proliferation studies, and metabolic signaling investigations. These publications describe experimental contexts in which molecular interactions, receptor activation markers, and pathway-associated signaling components were observed and recorded.
Reported research contexts include examination of:
- IGF-1 receptor (IGF-1R) binding dynamics and activation patterns in experimental models
- PI3K/Akt/mTOR pathway-associated signaling components observed in cellular research settings
- MAPK cascade markers and cellular proliferation indicators evaluated under experimental conditions
- IGF-binding protein (IGFBP) interaction profiles and bioavailability dynamics assessed in preclinical contexts
- Comparative receptor engagement and half-life profiles relative to native IGF-1 in experimental systems
All reported applications are confined to descriptive investigation within controlled laboratory research environments.
Mechanistic discussions in preclinical publications describe IGF-1 LR3 as an IGF-1 analog in which the arginine substitution at position 3 and N-terminal extension are described as substantially reducing affinity for IGFBPs, particularly IGFBP-3, thereby extending circulating bioactivity relative to the native peptide. These descriptions are limited to molecular and biochemical observations within experimental systems and do not imply functional outcomes beyond the reported research context.
IGF-1 LR3 is supplied as a research-grade peptide material. Identity and composition have been reported as characterized using analytical techniques commonly applied to peptide research materials, including chromatographic and mass spectrometric methods. Individual laboratories determine handling, storage, and analytical verification parameters in accordance with internal research protocols.
COA
Storage
All of our products are manufactured using the Lyophilization (Freeze Drying) process, which ensures that our products remain 100% stable for shipping for up to 3-4 months. Once the peptides are reconstituted (mixed with bacteriostatic water), they must be stored in the fridge to maintain stability. After reconstitution, the peptides will remain stable for up to 30 days.
Lyophilization is a unique dehydration process, also known as cryodesiccation, where the peptides are frozen and then subjected to low pressure. This causes the water in the peptide vial to sublimate directly from solid to gas, leaving behind a stable, crystalline white structure known as lyophilized peptide. The puffy white powder can be stored at room temperature until you're ready to reconstitute it with bacteriostatic water.
Once peptides have been received, it is imperative that they are kept cold and away from light. If the peptides will be used immediately, or in the next several days, weeks or months, short-term refrigeration under 4°C (39°F) is generally acceptable. Lyophilized peptides are usually stable at room temperatures for several weeks or more, so if they will be utilized within weeks or months such storage is typically adequate.
For longer term storage (several months to years) it is more preferable to store peptides in a freezer at -80°C (-112°F). When storing peptides for months or even years, freezing is optimal in order to preserve the peptide's stability.
Lyophilization is a unique dehydration process, also known as cryodesiccation, where the peptides are frozen and then subjected to low pressure. This causes the water in the peptide vial to sublimate directly from solid to gas, leaving behind a stable, crystalline white structure known as lyophilized peptide. The puffy white powder can be stored at room temperature until you're ready to reconstitute it with bacteriostatic water.
Once peptides have been received, it is imperative that they are kept cold and away from light. If the peptides will be used immediately, or in the next several days, weeks or months, short-term refrigeration under 4°C (39°F) is generally acceptable. Lyophilized peptides are usually stable at room temperatures for several weeks or more, so if they will be utilized within weeks or months such storage is typically adequate.
For longer term storage (several months to years) it is more preferable to store peptides in a freezer at -80°C (-112°F). When storing peptides for months or even years, freezing is optimal in order to preserve the peptide's stability.
