Dihexa

Nootropic / HGF Pathway Potentiator

Also known as: PNB-0408 · N-hexanoic-Tyr-Ile-(6) aminohexanoic amide

A potent nootropic compound that amplifies hepatocyte growth factor (HGF) signaling in the brain, promoting synaptogenesis & cognitive enhancement with effects far exceeding those of BDNF in animal models.

Typical Dose

1–10 mg orally, 2–3x per week

Route

Oral (primary) or subcutaneous injection

Cycle

4–8 weeks on; off period recommended

Half-life

Unknown in humans. Animal data suggests prolonged CNS retention.

Storage

Powder: room temp. Reconstituted for injection: 2–8°C, use within 30 days.

Overview

Dihexa is a small peptidomimetic compound derived from angiotensin IV that acts as a potentiator of the MET/HGF (hepatocyte growth factor/c-Met) pathway. In the brain, HGF/c-Met signaling drives synaptogenesis, dendritic spine formation, & neural plasticity. Dihexa increases the density & efficacy of synaptic connections rather than simply modulating neurotransmitter levels.

Animal studies at Washington State University showed cognitive improvements 7-fold greater than BDNF in spatial learning tasks, persisting after compound clearance — suggesting structural synaptic changes rather than acute neurochemical effects. Human data is limited to case reports & small open-label observations.

Dihexa is orally bioavailable & blood-brain-barrier penetrant. It is primarily used in neurological decline & cognitive enhancement contexts. Given its potency & limited human data, conservative dosing & monitoring are recommended.

Quick Start Guide

Oral: 1–10 mg orally. Most users start at 2–5 mg.

Effects can be long-lasting; some protocols use 2–3x per week rather than daily.

Allow 2–4 weeks before assessing full cognitive effect.

Research Indications

Cognitive enhancement (synaptogenesis)

Effective

Animal data shows dramatic improvement in spatial learning & memory with structural synaptic changes. Effects persist after compound clearance. Limited human data.

Neurological decline

Moderate

HGF/c-Met pathway is reduced in Alzheimer's disease & traumatic brain injury. Dihexa theoretically addresses this deficit.

Research Protocols

Cognitive enhancement

4–8 weeks; then 4-week break

Dose

2–5 mg oral

Frequency

2–3x per week

Route

Oral

Peptide Interactions

SemaxCompatible

BDNF (Semax) + HGF (Dihexa) pathway combination. Both drive neuroplasticity through different mechanisms.

Side Effects & Safety

Common

Headache (reported in some users)
Mild GI upset (oral route)

Uncommon

Irritability
Sleep disturbance

When to Stop

Signs of allergic reaction
Neurological symptoms

How to Reconstitute

For oral use: mix powder in water or oil carrier.

For SubQ: reconstitute in BAC water. Swirl gently. Refrigerate.

Dosing math: Most commonly used orally. If SubQ: 1 mg/mL in BAC water.

Quality Indicators

Good — use as normal

White/off-white powder dissolving fully in solution

Discard immediately

Unusual color or odor

What to Expect

Week 1–2

Subtle cognitive changes. Some users notice improved word retrieval or problem-solving clarity within the first week.

Week 3–6

More consistent cognitive improvements. Synaptogenesis is accumulating. Animal data suggests structural changes that persist after dosing ends.

Community Insights

Self-reported. Reflects user experience, not clinical outcomes.

Research References

Angiotensin IV (Dihexa) improves spatial learning performance in a rat model of Alzheimer's disease

Journal of Neurochemistry · 2011

Demonstrates 7-fold greater cognitive enhancement versus BDNF in spatial learning tasks via HGF/c-Met synaptogenesis.

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Information on this page applies to pharmaceutical-grade peptides. Purity & identity of research-grade products vary. Certipep provides independent ESI-TOF-MS & HPLC analysis with a signed analytical report.

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