Semax

Approved in Russia (Investigational elsewhere) Cognitive / Neurological

A neuroprotective peptide approved in Russia for stroke recovery and cognitive enhancement.

Also Known As
ACTH (4-10) analog, Mexidol-N (Russia)
Status
Approved in Russia (Investigational elsewhere)
Category
Cognitive / Neurological
Route
Intranasal spray or injection

What Is Semax?

Semax is a synthetic heptapeptide developed at IMGRAN (Institute of Molecular Genetics, Russian Academy of Sciences). It is based on the 4-10 fragment of ACTH (adrenocorticotropic hormone) — a sequence that possesses the neurological activity of ACTH without its endocrine effects. Additional amino acids were added to create Semax (MEHFPGP) with enhanced stability and CNS activity.

Semax's primary mechanism is stimulation of BDNF (brain-derived neurotrophic factor) and NGF (nerve growth factor) expression in the brain. These neurotrophic factors are essential for neuronal survival, growth, and synaptic plasticity — the biological basis of learning and memory. Semax also modulates dopaminergic, serotonergic, and other neurotransmitter systems.

In Russia and Ukraine, Semax is approved for treatment of stroke, transient ischemic attack (TIA), cognitive disorders, and as a general neuroprotectant. It has been used in the Russian military for cognitive performance enhancement. As a nasal spray, it offers a non-invasive delivery route that appears to allow direct transport to the CNS via olfactory neurons.

What The Research Says

Russian clinical trials demonstrate neuroprotective effects in ischemic stroke — accelerated recovery, reduced cognitive impairment, and improved neurological outcomes. Studies in patients with cognitive decline show memory improvements. BDNF upregulation has been confirmed in multiple preclinical and clinical studies.

Preclinical research demonstrates Semax improves memory consolidation, protects against various forms of experimental brain damage, and has antidepressant-like effects. It appears to promote long-term synaptic potentiation — a cellular basis of memory. Western clinical trial validation is lacking but the scientific rationale is sound.

📚 Key Reference: PMID: 12564946 (Semax neuroprotection), PMID: 22943340 (BDNF effects)

Common Uses

Important Safety Information

Generally well-tolerated in clinical use. Nasal administration is non-invasive. Reported side effects: mild nasal irritation, headache, transient mood changes. Risk of blood pressure changes due to dopaminergic effects. Not FDA-approved; consult your provider about any underlying conditions that might be affected.

Questions To Ask Your Provider

  1. What cognitive condition or goal makes me a candidate for Semax?
  2. What evidence supports Semax for my specific situation?
  3. How does intranasal delivery compare to injectable for CNS penetration?
  4. What interactions might exist with my current medications?
  5. How will cognitive improvement be measured?

Regulatory Status

Approved in Russia and Ukraine for neurological conditions. NOT FDA-approved in the US. Available through compounding pharmacies. Nasal formulations are more common.

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Disclaimer: This information is for educational purposes only. PepKey does not diagnose, prescribe, or recommend dosages. Always consult a licensed healthcare provider before starting any peptide therapy. Full disclosure
Last updated: 2026-04-08 · ← Back to Peptide Library