FGL Peptide
Also known as: FG Loop peptide · NCAM mimetic peptide
A 15-amino-acid peptide mimetic of the FGL loop of the neural cell adhesion molecule (NCAM), studied for neurogenic, synaptogenic, and memory-enhancing effects in cellular and animal research.
- Category
- Neurogenesis
- Half-life
- Pharmacodynamic effects extend beyond plasma exposure
Section 1
Overview
FGL is a 15-amino-acid peptide derived from the second fibronectin type-III domain of the neural cell adhesion molecule (NCAM). NCAM is a cell-surface protein critical to neural development, synaptogenesis, and adult neural plasticity; the FGL peptide reproduces the key receptor-binding motif and acts as a small-molecule mimetic for the full NCAM interaction.
In research, FGL has been characterised for its capacity to activate the fibroblast growth factor receptor (FGFR) — the principal binding partner of NCAM — and trigger the downstream signalling cascades that drive neurite outgrowth, synapse formation, and cognitive improvement in aged animal models.
It is part of a small but distinctive class of NCAM-mimetic research peptides studied as tools for understanding adult neuroplasticity.
Section 2
Discovery & History
- Developed by the laboratory of Elisabeth Bock and Vladimir Berezin at the University of Copenhagen, as part of a programme to map functional motifs in NCAM.
- Subject to a peer-reviewed literature from the early 2000s onwards covering mechanism, pharmacology, and behavioural effects in animal models.
- Has not progressed to formal clinical authorisation; remains a research peptide.
Section 3
Mechanism of Action
- 1Direct binding and activation of fibroblast growth factor receptor 1 (FGFR1), the principal NCAM partner.
- 2Activation of downstream FGFR signalling: PI3K-Akt, MAPK, PLCγ pathways implicated in neurite outgrowth and synaptogenesis.
- 3Promotion of neurite outgrowth and synapse formation in cell-culture work.
- 4Indirect modulation of BDNF and neurotrophin signalling downstream of FGFR activation.
- 5Anti-inflammatory effects in CNS injury models.
Section 4
Researched Benefits
Findings reported in the published preclinical and clinical literature. Effects in research contexts do not constitute claims of therapeutic benefit in humans.
- 1Cognitive improvement in aged-rat learning paradigms in published work.
- 2Promotion of neurite outgrowth and synaptogenesis in cell culture.
- 3Neuroprotection in models of CNS injury.
- 4Reported subcutaneous bioavailability sufficient for CNS effects in animal research.
- 5Defined molecular target (FGFR1) — clearer mechanistic story than many peptide research tools.
Section 5
Theoretical Dosing & Protocols
| Route | Dosage | Frequency | Duration |
|---|---|---|---|
| Subcutaneous / intranasal (research) | Microgram to milligram range in animal research | Daily during study courses | Variable across published protocols |
Section 6
Administration Routes
- Subcutaneous in most animal research.
- Intranasal in some protocols.
Section 7
Safety Profile
Commonly reported
- · Limited safety data — animal research only
Rare / theoretical
- · Theoretical considerations relating to systemic FGFR activation
- · FGFR signalling is implicated in some oncogenic processes — long-term human safety implications are uncharacterised
Contraindications
- · Not authorised for human use
- · Theoretical contraindication in subjects with active or historic malignancy
- · No data in pregnancy, lactation, or developmental contexts
Section 8
UK & EU Regulatory Context
United Kingdom
Not a licensed medicine in the UK. Research chemical only.
European Union
Not approved by the EMA.
Section 9
Clinical Studies Summary
FGL peptide and cognitive enhancement in aged rats
Improved Morris water maze performance in aged rats receiving FGL versus vehicle controls.
FGL as an FGFR1 agonist — mechanism study
Direct demonstration that FGL binds and activates FGFR1, and that downstream cognitive effects depend on FGFR1 integrity.
FGL in models of neuroinflammation
Reduction in inflammatory markers and improved outcomes in animal models of CNS injury.
Section 10
Frequently Asked Questions
Section 11
Sourcing for Laboratory Research
Sourcing FGL Peptide for laboratory research
Researchers in the United Kingdom and elsewhere typically obtain FGL Peptide from specialist research-chemical suppliers. Purity, third-party testing, and supplier transparency are the principal differentiators worth evaluating before placing an order. The two suppliers below are commonly referenced in UK research contexts.
Reminder: research peptides are sold strictly for in vitro and preclinical laboratory purposes. Importation or supply for human consumption is not permitted under UK medicines legislation.