Semax

Research OnlyModerate Evidence
Written by dr-sarah-chen|Reviewed by Healthier Rx Editorial Board|Updated 2026-04-01|4 min read
Quick Facts
TypeCognitive
FDA StatusResearch Only
Evidence LevelModerate Evidence
Typical Dose200-600mcg
Frequency1-2x daily
Cycle Length4-8 weeks
Key GoalsCognitive Enhancement

How It Works

Semax is a synthetic heptapeptide analog of the adrenocorticotropic hormone (ACTH) fragment 4-10, with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Developed at the Institute of Molecular Genetics of the Russian Academy of Sciences, it has been approved in Russia since the 1990s for treatment of stroke, cognitive disorders, and optic nerve atrophy.

Semax works through several key mechanisms. It increases brain-derived neurotrophic factor (BDNF) expression in the hippocampus and frontal cortex in a dose-dependent manner. BDNF is critical for neuronal survival, synaptic plasticity, and long-term memory formation. Additionally, Semax modulates dopaminergic and serotonergic neurotransmission, which contributes to improved focus, motivation, and mood.

The peptide also exhibits neuroprotective properties, reducing oxidative stress and neuroinflammation. In cerebral ischemia models, Semax has demonstrated the ability to reduce infarct size and improve neurological recovery.

Benefits

  • Enhanced cognitive function — improved memory, focus, and mental clarity in clinical observations
  • Neuroprotective effects — demonstrated in stroke and ischemic injury models
  • Increased BDNF expression — supports neuroplasticity and long-term learning
  • Modulation of dopamine and serotonin — may improve motivation and mood
  • Treatment of optic nerve atrophy — approved indication in Russia

Side Effects

  • Generally well-tolerated with a favorable safety profile based on decades of clinical use in Russia
  • Nasal irritation — common with intranasal administration
  • Mild headache — occasionally reported
  • Dizziness — rare
  • Hair loss — anecdotally reported at higher doses (potentially related to melanocortin signaling)
  • No significant organ toxicity or dependency reported in published literature

Dosing Protocol

ParameterDetails
Standard Dose200-600mcg per administration
Frequency1-2 times daily
AdministrationIntranasal spray (preferred) or subcutaneous injection
Cycle Length4-8 weeks on, 2-4 weeks off
TitrationStart at 200mcg and increase based on response

What You Will Need

  • Semax nasal spray (0.1% solution, typically 3mg/mL) or lyophilized vial for injection
  • Bacteriostatic water (if reconstituting for injection)
  • Insulin syringes (for subcutaneous injection route)
  • Alcohol swabs

Frequently Asked Questions

References

  1. Semax, an ACTH(4-10) analogue with nootropic properties, activates dopaminergic and serotoninergic brain systems in rodentsNeurochemical Research (2008). PMID: 17990098

    Demonstrates Semax modulation of dopamine and serotonin systems underlying its cognitive-enhancing effects.

  2. Semax (MEHFPGP) dose-dependently increases BDNF mRNA expression in rat hippocampus and frontal cortexDoklady Biological Sciences (2006). PMID: 17514475

    Shows Semax upregulates BDNF expression in brain regions critical for memory and learning.

  3. Neuroprotective effects of Semax in conditions of global cerebral ischemiaBulletin of Experimental Biology and Medicine (2011). PMID: 22268921

    Evidence for Semax neuroprotection in ischemic stroke models with improved neurological outcomes.

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Medical Disclaimer

This content is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider before starting any new treatment or protocol. Read our full medical disclaimer.