Cognitive & Nootropic

FGL

NCAM FG-loop · FG loop peptide · FGL peptide

Synthetic peptide from the NCAM FG loop, studied as an FGFR-modulating neural cell-adhesion mimetic (PMID 14642282). Research-chem nootropic SKU. Not a stroke drug. Distinct from P21 (CNTF-derived), which we already list.

Not FDA-approved — research chemical
Reviewed by CalcMyPeptide Editorial Team
Last updated: April 2026Evidence: Low1 peer-reviewed citation
Typical research dose
Research; vendor nasal/SC ranges are not a label
Frequency
Not established
Half-life
Short (SKU unpublished)
Common vials
5 mg / 10 mg
CAS
N/A
Dose it
5 mg + 2.5 mL BAC water → 2 mg/mL · 200 mcg ≈ 10 units (U-100)
Open in calculator

Mechanism of Action

FGL is a peptide from the NCAM FG loop, published as an FGFR-interacting neural cell-adhesion mimetic (PMID 14642282). It is a different molecule from P21 (CNTF-derived), which we already list.

Nootropic vendor SKUs are not stroke or dementia care.

Source: PMID: 14642282

Dosing Protocol

Typical DoseResearch; vendor nasal/SC ranges are not a label
FrequencyNot established
Half-LifeShort (NCAM mimetic peptide; SKU PK unpublished)
Common Vial Sizes5 mg, 10 mg

Dosing Protocols

Research

Dose
Vendor ranges only
Frequency
n/a
Note: Not a label.

Administration

Route
Intranasal or SC (vendor)
Timing
Not established.
Fasting Required?
No — food timing not critical

Expected Timeline

Unknown in consumers
Neural-plasticity papers are not a stack timeline.

Who Is It For?

Nootropic research identity

Low

Listed because Pepdex-class catalogs include it. Distinct from P21.

Reconstitution Example

Vial
5 mg
Diluent
2.5 mL
Concentration
2 mg/mL
Per Unit (100u syringe)
20 mcg
Dose of 200 mcg = 10 units on a 100-unit insulin syringe
🧮 Calculate Your Exact FGL Dose →

Safety & Considerations

Research peptide. FGF-adjacent signaling is not a toy. Not a substitute for neurology care.

Regulatory & Legal Status

FDA Status (US)
Research Only

NCAM FG-loop mimetic. Research-only

WADA Status (2026)
Not Listed

Not currently on the WADA 2026 Prohibited List. Policies may change — verify before competition.

Classification

Research Chemical

US Compounding: Not eligible / not available

⚠️ This information is for educational purposes only and may not reflect the most current regulatory updates. Always verify with official FDA, WADA, and jurisdiction-specific sources before use.

FGL vs. P21

AttributeFGLP21
OriginNCAM FG loopCNTF-derived (P021)
Claimed jobFGFR / neural CAM mimeticNeurotrophic CNTF fragment
Human PKSKU unpublishedEstimated / research

Verdict: Two different nootropic research peptides. FGL is not P21 with a new name.

Dosing Quick Reference

FGL— Dosing Guide
Dose Range
Research; vendor nasal/SC ranges are not a label
Half-Life
Short (NCAM mimetic peptide; SKU PK unpublished)
Frequency
Not established
Route
Subcutaneous
5 mg vial10 mg vial
💧 2.5 mL BAC water📐 2 mg/mL💉 20 mcg/unit (100u syringe)
Cognitive & Nootropiccalcmypeptide.com

Frequently Asked Questions

Is FGL the same as P21?▼
No. FGL is NCAM FG-loop. P21 is CNTF-derived. Separate IDs.

References

  1. Kiselyov VV et al. “The neural cell adhesion molecule-derived peptide FGL.” Structure / related NCAM literature (2003). PMID: 14642282

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