Limited ResearchCognitive

FGL

FG Loop Peptide

NCAM-Derived Peptide | Synaptic Plasticity & Neuroprotection

Half-life

Not well characterized

Chain length

15 amino acids

Reference frequency

1x daily

Research overview

DoseGear research brief

FGL is a synthetic peptide derived from the second fibronectin type III module of neural cell adhesion molecule (NCAM). It mimics the interaction between NCAM and fibroblast growth factor receptor 1 (FGFR1), activating downstream signaling cascades that promote synaptic plasticity, neurogenesis, and neuroprotection. Research has primarily been conducted in animal models, where FGL has shown promise for cognitive enhancement, stroke recovery, and neurodegenerative disease models.

Mechanism of action

FGL binds to and activates FGFR1, triggering receptor autophosphorylation and downstream signaling through the MAPK/ERK and PI3K/Akt pathways. This activation promotes long-term potentiation (LTP), enhances synaptic plasticity, stimulates neurogenesis in the hippocampus, and provides neuroprotective effects against excitotoxicity and oxidative stress.

Compound background

Development & research timeline

Study windows describe what researchers measured, not when an individual should expect a result.

Origin & development

Synthetic peptide derived from an NCAM fibronectin-type-III region.

What it is researched for

Synaptic plasticity, neuroprotection, and cognition research involving FGFR1-associated MAPK/ERK and PI3K/Akt signaling.

Research observation window

Not reported in the reviewed compound-specific evidence.

Reference data

Lyophilized vial injectable protocols

Not personalized dosing instructions

Only injectable vial references are shown. Nasal, topical, and unsupported non-vial schedules are excluded.

Research context	Amount	Frequency	Route
Cognitive support (research protocol)	100-200mcg	1x daily	SubQ

Reference cycle

Research protocols vary; limited human data on cycling

Reference storage

Lyophilized: -20C; Reconstituted: 2-8C, use within 4 weeks

Safety context

Reported side effects

Injection site reactions (redness, mild swelling, irritation)

Contraindications & cautions

Pregnancy or breastfeeding
Known peptide or NCAM-related compound allergies
Very limited human safety data -- use with caution under medical supervision

Scientific references

01
A Peptide Agonist of the Neural Cell Adhesion Molecule NCAM, FGL, Enhances Synaptogenesis and Memory in Rats
Scientific citationA Peptide Agonist of the Neural Cell Adhesion Molecule NCAM, FGL, Enhances Synaptogenesis and Memory in Rats. European Journal of Neuroscience (2009).
02
FGL, a Neural Cell Adhesion Molecule-Derived Peptide, Promotes Recovery in a Rat Model of Stroke
Scientific citationFGL, a Neural Cell Adhesion Molecule-Derived Peptide, Promotes Recovery in a Rat Model of Stroke. European Journal of Neuroscience (2013).
03
The FGL Peptide Derived from NCAM Acts as a Neurotrophic Factor and Promotes Neurite Outgrowth and Survival of Neurons
Scientific citationThe FGL Peptide Derived from NCAM Acts as a Neurotrophic Factor and Promotes Neurite Outgrowth and Survival of Neurons. Journal of Neurochemistry (2004).
04
Enhancement of Long-Term Potentiation and Memory by the NCAM-Derived Peptide FGL
Scientific citationEnhancement of Long-Term Potentiation and Memory by the NCAM-Derived Peptide FGL. Neuropharmacology (2008).

This DoseGear profile combines published scientific literature with lyophilized-vial protocol references. Citations are provided for independent review.

Related research profiles

Cognitive

FGL