IGF-1 LR3 (Long R3 Insulin-like Growth Factor-1) is an 83-amino-acid synthetic analog of human IGF-1, engineered with an arginine substitution at position 3 and a 13-residue N-terminal extension. These modifications sharply reduce binding to IGF-binding proteins, giving the molecule a substantially longer functional presence than native IGF-1 in experimental systems, a property that makes it a favored tool for studying growth-factor receptor signaling over extended timeframes. Puritide Research supplies IGF-1 LR3 as a high-purity, research-use-only material, synthesized for in vitro and animal-model work and backed by third-party-verified certificates of analysis.
Available Sizes
- ›IGF-1 LR3 0.1 mg Vial
- ›IGF-1 LR3 1 mg Vial
Product Specifications
- Application
- Growth-factor receptor signaling and cell-proliferation research (IGF-1R pathway)
- Appearance
- Solid, white lyophilized powder in a sealed glass vial
- Chemical Formula
- C400H625N111O115S9
- CAS Number
- 143045-27-6
- Molecular Weight
- ~9117.60 g/mol
- Synonyms
- IGF-1 LR3, Long R3 IGF-1, LR3-IGF-1, Long Arg3 IGF-1, IGF1-LR3
- Storage
- Store at ≤25°C, sealed, away from heat, light, and moisture. For extended storage, keep lyophilized and refrigerated or frozen.
What Is IGF-1 LR3?
IGF-1 LR3 is a modified recombinant analog of insulin-like growth factor-1, a signaling peptide central to cellular growth, differentiation, and metabolism. It differs from native IGF-1 by an arginine-for-glutamic-acid substitution at the third position and an additional 13 amino acids at the N-terminus, extending the chain to 83 residues in total.
The defining consequence of these changes is markedly diminished affinity for IGF-binding proteins (IGFBPs). Because IGFBPs normally sequester circulating IGF-1, reducing that interaction leaves more of the analog available to engage the IGF-1 receptor in experimental systems, and prolongs its functional window relative to the native peptide.
Present understanding of IGF-1 LR3 derives from in vitro assays and animal models. Findings should be interpreted within their experimental context and not treated as established clinical outcomes. Puritide Research supplies IGF-1 LR3 strictly for laboratory use; it is not approved for human or veterinary application.
IGF-1 LR3 Mechanism of Action (Research Only)
IGF-1 LR3 is studied for its engagement of the IGF-1 receptor (IGF-1R), a receptor tyrosine kinase that initiates intracellular signaling cascades upon activation. The observations below reflect biochemical assays and cell-culture studies and should be read strictly in a research context.
Reduced IGFBP Binding
The arginine substitution and N-terminal extension in IGF-1 LR3 lower its affinity for the family of IGF-binding proteins. In experimental systems this reduced sequestration is associated with greater availability of the analog to interact with its receptor and a longer functional presence than native IGF-1, making the compound useful for studies of sustained receptor engagement.
IGF-1R Activation and Downstream Signaling
Upon binding IGF-1R, the receptor's intrinsic tyrosine kinase activity is triggered, recruiting adaptor proteins and initiating the PI3K/AKT/mTOR and RAS/MAPK/ERK signaling axes. These pathways are widely studied for their roles in protein synthesis, cell proliferation, and survival within controlled models.
Researchers use IGF-1 LR3 to examine the temporal dynamics of these cascades with greater resolution than native IGF-1 permits, characterizing receptor activation, adaptor recruitment, and downstream responses under defined conditions rather than establishing physiological effects.
IGF-1 LR3 Research Applications
IGF-1 LR3 is investigated across cell-biology and preclinical studies as a tool for probing growth-factor receptor signaling. The observations below derive from biochemical studies, cell-based assays, and animal models, and should be interpreted within their respective settings.
Receptor Signaling and Cell Proliferation Models
A primary application is investigating IGF-1R activation and the downstream PI3K/AKT and MAPK/ERK cascades in cultured cells. The analog's prolonged availability makes it valuable for studying signaling kinetics, receptor desensitization, and proliferative responses across extended experimental windows.
IGF-1 LR3 is also used in comparative research contrasting native IGF-1 with binding-protein-resistant analogs, examining differences in receptor engagement duration and downstream signal amplitude without establishing therapeutic superiority.
Myogenic, Metabolic, and Tissue-Culture Studies
Researchers apply IGF-1 LR3 in myoblast differentiation models, glucose-uptake assays, and broader tissue-culture systems to study the growth-factor's influence on cellular metabolism and differentiation. These studies aim to clarify receptor-mediated signaling rather than to establish physiological or performance outcomes.
Laboratory Safety & Handling (Research Use Only)
IGF-1 LR3 is a synthetic, lyophilized research peptide for laboratory investigation only. It should be handled by qualified personnel in controlled environments, in accordance with institutional policies, laboratory safety procedures, and applicable regulations. As an investigational material, laboratories should implement practices that prioritize material integrity, traceability, and reproducibility.
Handling & Storage Guidelines
Follow institutional SOPs, chemical hygiene plans, and approved protocols; wear appropriate PPE (lab coat, gloves, eye protection); and use engineering controls where required. Record lot numbers, storage conditions, and handling activities, and retain Certificates of Analysis and batch documentation to support traceability and audit readiness.
Store material under the conditions specified in product documentation, protected from excessive heat, moisture, and direct light. Reconstituted material is less stable than the lyophilized powder and should be kept refrigerated and used within the timeframe indicated by your protocol. Consistent handling and documentation support reliable, reproducible outcomes.
Certificate of Analysis & Quality Assurance
Each IGF-1 LR3 batch ships with a third-party-verified Certificate of Analysis, providing transparent, research-grade quality control. The CoA includes a purity assessment (HPLC / reverse-phase chromatography), mass-spectrometry identity confirmation, and lot number, testing date, and method documentation.
Researchers may request sample CoAs (PDF) ahead of purchase to confirm testing parameters, analytical methods, and batch consistency, and are encouraged to perform independent verification.
Research Use Only
