IGF-1 LR3 (Long R3 IGF-1) is a synthetic 83-amino-acid analog of human insulin-like growth factor 1 (IGF-1). It differs from native IGF-1 by an arginine substitution at position 3 and a 13-residue N-terminal extension, modifications that increase its stability and reduce its binding to IGF-binding proteins in research models. It is studied in preclinical and cell-culture research as a tool compound for investigating IGF-1-receptor signaling.
IGF-1 LR3 is a fully synthetic analog and does not occur natively in this modified form. As supplied for research, it is a lyophilized powder that is water-soluble on reconstitution.
Verified dataVerified compound data
| Property | Value |
|---|---|
| Compound name | IGF-1 LR3 (Long R3 IGF-1, LR3-IGF-1) |
| CAS number | 143045-27-6 |
| Molecular formula | C400H625N111O115S9 |
| Molecular weight | ~9117.60 g/mol |
| Length | 83 residues (Arg3 substitution + 13-residue N-terminal extension) |
| Sequence | MFPAMPLSSLFVNGPRTLCGAELVDALQFVCGDRGFYFNKPTGYGSSSRRAPQTGIVDECCFRSCDLRRLEMYCAPLKPAKSA |
| Physical form | Lyophilized powder |
Data verified against Wikipedia (IGF-1 LR3) and corroborating references: 83 amino acids, MW 9117.60, formula C400H625N111O115S9, CAS 143045-27-6. PubChem does not maintain a single canonical small-molecule CID for the full-length analog; it is identified here by formula, sequence, and CAS.
MechanismResearch-context mechanism
In preclinical literature, IGF-1 LR3 is studied as an agonist at the IGF-1 receptor. The Arg3 substitution and N-terminal extension are studied for reducing the analog’s affinity for IGF-binding proteins, which in research models is associated with increased free-analog availability relative to native IGF-1. Receptor-binding and downstream cell-signaling pathways are examined in in vitro and animal research models. These mechanisms are described strictly in a research-model context; they are not established human-use mechanisms.
Research summaryCurrent research summary
IGF-1 LR3 appears across cell-culture and preclinical literature as a stabilized IGF-1 analog research tool. Reported research areas include:
- IGF-1-receptor binding and agonism studies
- IGF-binding-protein interaction research models
- Cell-signaling and proliferation studies in culture
- Comparative pharmacokinetics vs native IGF-1 (preclinical)
The existing body of work is predominantly in vitro and animal. IGF-1 LR3 is not an FDA-approved drug and has no established human therapeutic use. All framing here is strictly laboratory research.
QuestionsFrequently Asked Questions
What is IGF-1 LR3?
IGF-1 LR3 is an 83-amino-acid synthetic analog of insulin-like growth factor 1, studied in preclinical IGF-1-receptor and cell-signaling research models. It is a research compound supplied as a lyophilized powder and is not approved for human use.
What is the molecular formula of IGF-1 LR3?
The molecular formula of IGF-1 LR3 is C400H625N111O115S9, with a molecular weight of approximately 9117.60 g/mol.
What is the CAS number for IGF-1 LR3?
The CAS registry number for IGF-1 LR3 is 143045-27-6.
How does IGF-1 LR3 differ from native IGF-1?
IGF-1 LR3 carries an arginine substitution at position 3 and an additional 13-residue N-terminal extension, giving it 83 residues versus native IGF-1’s 70. In research models these modifications are studied for increased stability and reduced binding-protein affinity.
How is IGF-1 LR3 stored and reconstituted in a research setting?
Lyophilized IGF-1 LR3 is stored at 2 to 8°C, protected from light and humidity. It is reconstituted with a suitable sterile solvent, is water-soluble, and reconstituted material is held at 4°C and used within about 30 days, avoiding repeated freeze-thaw cycles.
Is IGF-1 LR3 approved for human use?
No. IGF-1 LR3 is not an FDA-approved drug and is not intended for human consumption. It is offered strictly as a research compound for laboratory use.
For research use only. Not for human or veterinary use. Not approved by the FDA. 21+
- HPLC + MS tested, every batch
- U.S. synthesized
- Batch COA on the product page
$109View compound