What is the difference between Semax and Dihexa?

Semax (Semax (MEHFPGP)) is graded B and is Not FDA-approved in US — approved in Russia for stroke and cognitive disorders. Dihexa (Dihexa (PNB-0408)) is graded C and is Not FDA-approved — research compound (HGF/c-Met-mimetic). They are commonly compared because they share the categories: cognitive, neuroprotection.

Which has stronger clinical evidence — Semax or Dihexa?

On our internal evidence scale, Semax is B and Dihexa is C. A+ indicates large RCTs plus FDA approval; C indicates primarily preclinical or anecdotal evidence.

What is the typical dose of Semax vs Dihexa?

Semax: 200–600 mcg intranasal, morning. Dihexa: 8–45 mg orally daily (research-only). Always work with a licensed clinician — peptide dosing should be individualized.

Semax vs Dihexa

Both Semax and Dihexa are used for cognitive and neuroprotection. Here's how their evidence, dosing, and regulatory status actually compare.

Semax

Evidence B

Semax (MEHFPGP)

A synthetic ACTH fragment that increases BDNF levels and enhances focus, memory, and mental clarity. Delivered intranasally for rapid cognitive effects.

View full Semax profile →

Dihexa

Evidence C

Dihexa (PNB-0408)

An angiotensin IV-derived hexapeptide that mimics hepatocyte growth factor (HGF)/c-Met signaling and produced rapid synaptogenesis in animal models. No human trials.

View full Dihexa profile →

Side-by-Side

Attribute	Semax	Dihexa
Evidence Grade	B	C
FDA Status	Not FDA-approved in US — approved in Russia for stroke and cognitive disorders	Not FDA-approved — research compound (HGF/c-Met-mimetic)
Typical Dose	200–600 mcg intranasal, morning	8–45 mg orally daily (research-only)
Clinics Indexed	89	10
Categories	cognitive, neuroprotection	cognitive, neuroprotection

Key reported benefits — Semax

✓BDNF increase
✓Enhanced focus
✓Memory improvement
✓Neuroprotection

Key reported benefits — Dihexa

✓Synaptogenesis (preclinical)
✓Memory improvement (animal)
✓Possible Alzheimer's relevance

Educational use only

This comparison is for educational purposes and not medical advice. Peptide selection should be made with a licensed medical professional based on your individual goals, health history, and current evidence quality.

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