FGL
A synthetic 15-amino-acid NCAM-derived peptide that mimics neural cell adhesion molecule signaling to promote synaptic plasticity and neuroprotection in preclinical models.
FGL (EVYVVAENQQGKSKA) is a synthetic 15-amino-acid peptide derived from the fibronectin type III homology domain 2 of the neural cell adhesion molecule (NCAM). It was designed as a pharmacomimetic agonist of NCAM to activate FGFR-mediated neurotrophic signaling and reproduce the synaptogenic and neuroprotective effects of NCAM receptor engagement in the central nervous system. In rodent models FGL promotes synaptic plasticity, neuronal survival, and spatial learning, with reported cognitive-enhancing and anxiolytic effects in aged animals and neurodegeneration models. No human clinical trials, pharmacokinetic studies, or safety evaluations of FGL have been published, so the entire evidence base is preclinical.
Class
Synthetic NCAM-derived pentadecapeptide (FGFR agonist)
Routes
Subcutaneous
Category
Cognitive & Nootropic
Researched benefits
What it's studied for
Synaptic plasticity
FGL activates FGFR-mediated signaling to promote long-term potentiation (LTP) and synaptogenesis, the cellular processes that underlie learning and memory formation. Evidence is preclinical, drawn from rodent and in vitro models.
Memory enhancement
Rodent studies report improved spatial learning and cognitive performance following FGL administration, including in aged animals, supporting a preclinical rationale for memory and cognition research.
Neuroprotection
By mimicking NCAM engagement and activating neurotrophic FGFR downstream pathways, FGL supports neuronal survival in models of neurodegeneration. This benefit is documented only in animal and in vitro studies.
LTP promotion
FGL stimulates downstream Erk1/2 and PLCγ signaling cascades that drive long-term potentiation, a key electrophysiological correlate of synaptic strengthening and memory consolidation.
Anxiolytic effects (preclinical)
Rodent studies have reported anxiolytic-like behavioral effects alongside cognitive benefits, particularly in aged animals, though this remains an early preclinical observation.
Mechanism
How it works
FGL is a pharmacomimetic peptide derived from the fibronectin type III homology domain 2 of the neural cell adhesion molecule (NCAM). It was engineered to reproduce the receptor-binding activity of NCAM, acting as an agonist that engages the fibroblast growth factor receptor (FGFR) in the central nervous system.
Once FGFR is activated, FGL triggers downstream neurotrophic signaling through the Erk1/2 (extracellular signal-regulated kinase) and PLCγ (phospholipase C gamma) pathways. These cascades regulate gene transcription, neuronal survival, and the structural remodeling of synapses.
The net effect in preclinical models is promotion of long-term potentiation (LTP) and synaptogenesis, the biological substrates of learning and memory. By strengthening synaptic connections and supporting neuronal survival, FGL produces cognitive-enhancing, neuroprotective, and anxiolytic effects observed in aged rodents and models of neurodegeneration. All of these mechanisms are established in animal and in vitro systems only; no human data confirm the pathway in people.
Safety
Side effects & considerations
Contraindications & cautions
- Pregnancy or nursing
FGL is generally described as lower risk in research contexts, but no human safety data exist to characterize side effects, tolerability, or long-term risks. The absence of clinical evaluation means its true safety profile in humans is unknown. Individual response varies; pregnant or nursing individuals are listed as a contraindication.
FAQ
FGL — common questions
What is FGL?
FGL (sequence EVYVVAENQQGKSKA) is a synthetic 15-amino-acid peptide derived from the fibronectin type III homology domain 2 of the neural cell adhesion molecule (NCAM). It was designed as a pharmacomimetic agonist of NCAM to activate FGFR-mediated neurotrophic signaling and mimic the synaptogenic and neuroprotective effects of NCAM receptor engagement in the brain.
What is FGL primarily studied for?
FGL research focuses on synaptic plasticity, memory enhancement, neuroprotection, and the promotion of long-term potentiation (LTP).
What are the reported benefits of FGL?
Preclinical research documents effects related to synaptic plasticity, memory enhancement, neuroprotection, and LTP promotion. Rodent studies have also shown cognitive-enhancing and anxiolytic effects in aged animals and in models of neurodegeneration. Individual response varies and all findings are from animal or in vitro models.
Is there any human clinical evidence for FGL?
No. No published human clinical trials, pharmacokinetic studies, or safety evaluations of FGL have been indexed in PubMed. The entire evidence base consists of animal and in vitro studies.
How does FGL work?
FGL mimics NCAM-mediated signaling by activating the fibroblast growth factor receptor (FGFR), which stimulates downstream Erk1/2 and PLCγ pathways. This promotes long-term potentiation and synaptogenesis, the cellular basis of learning and memory.
Is FGL approved or legal?
FGL has no FDA approval or regulatory approval in any jurisdiction. It is a research-only compound that has not been evaluated for any human indication.
What are the side effects of FGL?
No human safety data exist. FGL is described as lower risk in research contexts, and pregnancy or nursing is listed as a contraindication. Because it has never been evaluated clinically, its side-effect profile in humans is unknown.
