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№ 049

FGL

Studied for memory and learning in animal models. It's an FG-loop peptide modeled on the FG-loop region of NCAM (neural cell adhesion molecule).

Nootropic
Evidence: Anecdotal

FGL: Studied for memory and learning in animal models. It's an FG-loop peptide modeled on the FG-loop region of NCAM (neural cell adhesion molecule). FGL is a synthetic peptide built around a loop of NCAM, a neural cell adhesion molecule.

FDA ⓘ
Not approved
WADA
Not banned
Typical dose
No standardized human dose
Half-life ⓘ
Short (~hours)
Route ⓘ
Subcutaneous or intranasal
Schedule
Daily
In plain English

FGL is a synthetic peptide built around a loop of NCAM, a neural cell adhesion molecule. Animal-model studies show memory and learning improvements. Almost no human data. Treat it as experimental.

Status & legalityWhat do these mean? →
Natty? ⓘ
Not natty
FDA ⓘ
Not approved

Not FDA approved. Pre-clinical.

Compounding ⓘ
Not classified

Not formally categorized in the FDA bulks lists.

WADA ⓘ
Not listed
Prescribed ⓘ

Not prescribed in conventional medicine.

Who it's for

  • →Researchers studying NCAM-FGFR pathways
  • →Neuroplasticity research
  • →Educational reference, limited human data

What to expect

  1. Week 1

    Subtle. Animal models show memory-task improvements emerging.

  2. Week 4

    Cycle endpoint in most animal protocols.

  3. Week 8

    Off-cycle. No human long term data.

Looking at FGL? Your next 3 steps

  1. 1Work out your exact dose

    Vial size + BAC water turns into the exact units to draw for FGL.

    Open calculator →
  2. 2See what to stack & monitor

    The companion supplements and the bloodwork worth tracking on this kind of protocol.

    Bloodwork guide →
  3. 3Save it & ask the Coach

    A free account saves your stack; membership adds the stack-aware AI Coach.

    Create free account →

How it works (mechanism)

Synthetic peptide modeled on the FG-loop of NCAM (neural cell adhesion molecule). Binds FGFR1, activating cascades that support synapse formation and memory in animal models.

Dosing protocol

Members only

Stacks well with

Members only

Side effects

01Limited human data
02Generally well tolerated in animal models

When NOT to use

  • ⚠Pregnancy / nursing
  • ⚠Anyone risk-averse to pre-clinical compounds

Common mistakes

  • • Treating it as a defined nootropic with established protocols
  • • Long cycles without safety data
Free, no account needed

New to FGL? Grab the starter checklist.

Drop your email and we'll send the one-page first-cycle starter checklist, plus a heads-up if FGL changes legal status. No account needed.

No spam. No selling your email. Just the checklist and the occasional reclassification alert.

AI Coach, live sample
Members only
is 250mcg of bpc enough for a knee injury?
For a knee, 250 mcg sub-q daily is the standard working dose and a solid place to start. The trick with BPC is consistency, give it weeks, not days. Inject close to the joint, run it 4-6 weeks, and don't drop below 200 mcg, it tends to stop cracking the threshold reliably down there. If it hasn't moved at all by week 3, that's when adding TB-500 earns its place.
how much bac water for a 10mg reta vial?
3 mL is the standard play for a 10 mg reta vial. That's 3,333 mcg/mL, clean unit math across the titration: 2 mg = 60 units, 4 mg = 120 units, 6 mg = 180 units on a 100-unit insulin syringe. Run 2 mL instead if you want fewer, more concentrated shots (5,000 mcg/mL, so 2 mg = 40 units). Since most people titrate up over ~12 weeks, 3 mL keeps the numbers cleanest.
what should i track on bloodwork for tirzepatide?
Lipid panel, ALT/AST (liver enzymes), and an A1C, baseline before you start then every 3 months. If you've got metabolic-syndrome history, add fasting glucose and insulin so you can actually watch insulin sensitivity improve. You don't need a big hormone panel for a GLP-1.

Ask the Coach anything about FGL or your own stack. This is it working.

Trained only on Pepdex content. Does the dose math, flags interactions, knows your stack. Won't push vendors, won't pretend to be a doctor.

Get the Coach, $7.99/mo →

Frequently asked

What is FGL?+
FGL is a synthetic peptide built around a loop of NCAM, a neural cell adhesion molecule. Animal-model studies show memory and learning improvements. Almost no human data. Treat it as experimental.
Is FGL FDA approved?+
Not FDA approved. Pre-clinical.
Is FGL legal?+
FGL is not FDA-approved. It is sold by compounding pharmacies (with a prescription) and as "research only" by peptide vendors. Possession is generally not criminalized but distribution without authorization may be. Verify local laws.
Is FGL banned by WADA?+
FGL is not currently on the WADA prohibited list.
Are you still natty after taking FGL?+
No. FGL is a performance-enhancing peptide and would disqualify a strict natty claim.
Do doctors prescribe FGL?+
Not prescribed in conventional medicine.
What's the typical dose of FGL?+
No standardized human dose. Animal-model dosing is per-kg and not directly translatable.
What are the side effects of FGL?+
Common side effects include: Limited human data; Generally well tolerated in animal models. Less common effects and full safety details are on the entry page.
How long until FGL starts working?+
Subtle. Animal models show memory-task improvements emerging.
What can you stack with FGL?+
Common pairings: Standalone, too early to stack. Full stacking protocol and timing on the entry page.
Where do people get FGL?+
FGL is most commonly sold by research-only peptide vendors and by compounding pharmacies (the latter requires a prescription). Pepdex is not a vendor, see /coa for how to verify a Certificate of Analysis before buying from any source, and /guides/scam-vendor-spotting for vendor red flags.

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