Because of its anabolic potential, IGF-1 LR3 has also attracted attention outside the laboratory — particularly in athletic enhancement contexts. However, the compound is strictly prohibited by the World Anti-Doping Agency (WADA) and is not approved by the U.S. Food and Drug Administration (FDA) for human therapeutic use. Its lawful status is limited to controlled laboratory research.
What Is IGF-1 LR3?
IGF-1 (Insulin-Like Growth Factor-1) is a peptide hormone naturally produced in the liver in response to growth hormone stimulation. It plays a key role in cellular proliferation, differentiation, and repair. IGF-1 LR3 was designed to enhance these properties by extending the molecule’s half-life from about 20 minutes to over 20 hours, as described in Humbel et al., 2000. This increased stability allows for longer experimental windows and more consistent bioactivity in cell culture and tissue models.
| Property | Description |
|---|---|
| Full Name | Insulin-Like Growth Factor-1 Long Arg3 (IGF-1 LR3) |
| Molecular Formula | C990H1528N262O300S7 |
| Half-Life | ~20–30 hours (vs. 20 minutes for native IGF-1) |
| Primary Research Focus | Cell proliferation, tissue regeneration, and stem cell differentiation |
| Regulatory Status | For Research Use Only (not FDA-approved; WADA-prohibited substance) |
Areas of Scientific Interest
(All information below is for educational and research use only.)
1. Cellular Growth and Regeneration
IGF-1 LR3 is a potent mitogen, meaning it promotes cell division and growth in various tissue types. Studies such as Li et al. (2013) have examined how IGF-1 signaling activates the PI3K/Akt pathway, a crucial driver of protein synthesis and muscle fiber development. In laboratory studies, this mechanism makes IGF-1 LR3 a valuable model compound for understanding tissue repair and regenerative biology.
2. Stem Cell Maintenance and Differentiation
Research has shown that IGF-1 supports stem cell proliferation and survival under controlled conditions. IGF-1 LR3’s extended activity window allows researchers to evaluate long-term differentiation and self-renewal effects in mesenchymal and neural stem cell lines. These findings contribute to studies in regenerative medicine, although no clinical applications are approved.
3. Muscle Growth and Performance Studies
Due to its anabolic signaling, IGF-1 LR3 has been studied in animal models for muscle hypertrophy and recovery. Elia et al. (2013) demonstrated increased protein synthesis and satellite cell activation in IGF-treated muscle tissue. However, these effects have also led to its misuse in sports, prompting its inclusion in the WADA prohibited list for performance-enhancing substances.
4. Metabolic and Insulin-Related Pathways
IGF-1 interacts with insulin signaling networks and contributes to glucose homeostasis. Studies such as Laron, 2004 have explored how IGF-1 analogs influence carbohydrate metabolism, cellular uptake, and insulin sensitivity. Understanding these pathways is crucial for developing safe experimental protocols involving metabolic markers.
Purity and Laboratory Standards
Research-grade IGF-1 LR3 should meet ≥99% purity, confirmed by high-performance liquid chromatography (HPLC) and mass spectrometry. Peptides are typically lyophilized and stored at –20°C, then reconstituted in sterile solvent immediately before use. Laboratories should document concentration, exposure time, and experimental conditions to maintain reproducibility and data integrity.
Compliance and Regulatory Considerations
IGF-1 LR3 is not approved by the FDA for human or veterinary use and is listed as a prohibited substance under WADA guidelines. It is distributed strictly for research use and must be handled within licensed facilities following institutional biosafety and ethical review policies. Marketing or administration for performance enhancement is illegal and may carry sanctions under anti-doping and pharmaceutical laws.
Why Researchers Are Interested
The appeal of IGF-1 LR3 lies in its molecular precision — its ability to extend IGF-1 receptor activation and sustain cell signaling without rapid degradation. Studies like Li et al., 2013 and Sun et al., 2018 highlight its significance in muscle repair, cellular differentiation, and regenerative modeling. Continued exploration under regulated laboratory conditions provides insight into growth factor biology and its translational potential in tissue engineering.
Laboratory Best Practices
- Source IGF-1 LR3 only from certified peptide manufacturers with validated Certificates of Analysis (COAs).
- Store lyophilized peptide at –20°C and reconstitute under sterile conditions.
- Maintain precise documentation of concentrations, exposure durations, and cell line identifiers.
- Dispose of experimental waste under biosafety and hazardous chemical regulations.
- Refrain from any human or animal administration outside authorized research protocols.
IGF-1 LR3 represents a powerful model peptide in regenerative and cellular research. Its extended half-life and high receptor affinity provide a stable framework for studying anabolic signaling, stem cell maintenance, and tissue repair mechanisms. While it remains a controlled research substance, its molecular design continues to inform future studies into growth factors, cellular recovery, and regenerative engineering under compliant laboratory conditions.
