Cognitive ⏱ Half-life: Not fully characterized in published data. Phase 1

FGL

FGL (FG Loop Peptide / NCAM Mimetic)

Updated March 15, 2026

Evidence at a Glance

Regulatory statusPhase 1
NCAM mimetic (FGLL); reached a Phase I intranasal safety/PK study in healthy volunteers (2007); no efficacy trials, development stalled
Human evidenceLimited
Animal evidenceModerate

A single first-in-human Phase I study found intranasal FGLL safe and tolerable, but every claim of memory or mood benefit comes from rat, primate and cell studies rather than human efficacy trials.

What the research does not support

  • It is not approved anywhere and has only a single small Phase I safety study in humans.
  • No human trial has shown it improves memory or treats Alzheimer's disease or depression.
  • Its cognitive, antidepressant and synaptic effects are documented only in rodents and cell cultures.
  • Clinical development appears to have stalled, so it is not a validated nootropic.
Half-Life
Not fully characterized in published data.
Mol. Weight
~1500 g/mol

What is FGL?

FGL is a peptide mimetic of neural cell adhesion molecule (NCAM) that activates fibroblast growth factor receptor signaling to promote synaptic plasticity and memory formation. It represents a targeted approach to enhancing the brain’s natural cell adhesion-mediated learning processes.

Research Applications

Memory enhancement, synaptic plasticity (LTP), age-related cognitive decline models, neuroprotection, and NCAM/FGFR signaling research.

Dosage Information (Research Use)

Animal research: 5-10 mg/kg subcutaneously or IV. Human dosing not established. Research use only.

Reconstitution & Handling

Standard BAC water reconstitution.

Half-Life & Pharmacokinetics

Not fully characterized in published data.

Reported Observations in Literature

Limited data. Generally well-tolerated in animal models.

Key Research References

  • Bhatt DK, et al. “FGL, a neural cell adhesion molecule-derived peptide, is neuroprotective.” Ann Neurol. 2005

How FGL Works

FGL is a synthetic peptide derived from the second immunoglobulin module of neural cell adhesion molecule (NCAM). It mimics the interaction between NCAM and the fibroblast growth factor receptor (FGFR), activating downstream neurotrophic signaling including MAPK/ERK and PI3K/Akt pathways. This promotes long-term potentiation (LTP), synaptic plasticity, and neuronal survival without requiring the full NCAM protein-protein interaction.

Research Findings

Animal studies show improved spatial memory in aged rats, enhanced social memory, and neuroprotection in ischemia models. One of the more targeted approaches to NCAM-based neurotrophic signaling. No human clinical trials published.

Dosage & Administration

Animal research: 5-10 mg/kg subcutaneously or IV. Human dosing not established. Research use only.

Safety & Side Effects

Limited data. Generally well-tolerated in animal models.

Important: All safety information is derived from published research, primarily animal studies. No controlled human clinical trial data exists unless explicitly noted. This compound is sold for research purposes only.

Quick Facts

Sequence Synthetic peptide from the FG loop of NCAM Ig module 2
Molecular Weight ~1500 g/mol
Half-Life Not fully characterized in published data.
Available Sizes 5mg
Storage Lyophilized: -20°C. Reconstituted: 2-8°C.

Key Research References

  • Bhatt DK, et al. "FGL, a neural cell adhesion molecule-derived peptide, is neuroprotective." Ann Neurol. 2005

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