Semax is a synthetic peptide consisting of the ACTH(4-7) fragment (Met-Glu-His-Phe) with a C-terminal Pro-Gly-Pro tripeptide. It was developed at the Institute of Molecular Genetics in Russia for cognitive enhancement and neuroprotection.

Semax upregulates BDNF protein levels by 1.4-fold and increases TrkB phosphorylation 1.6-fold. It also modulates BDNF, NGF, and TrkB gene expression, enhances dopamine and serotonin neurotransmission, and improves cerebral blood flow.

Is Semax FDA approved?

No. Semax is approved in Russia and Ukraine for treating stroke, cognitive disorders, and peptic ulcers. It is not FDA-approved and remains a research compound in the US and EU.

How is Semax administered?

Semax is administered intranasally as a 0.1% or 1% solution. The standard dose is 200-600 mcg per day intranasally. The 1% formulation (Semax 1%) is used for more serious neurological conditions.

Does Semax have side effects?

Semax is generally well-tolerated. Mild nasal irritation may occur. Unlike ACTH, Semax does not significantly stimulate adrenal hormone production at therapeutic doses.

How is Semax different from Selank?

Both are Russian peptides with Pro-Gly-Pro extensions, but they target different systems. Semax is primarily nootropic (BDNF, cognition, neuroprotection) while Selank is primarily anxiolytic (GABA modulation, anxiety reduction). They are often used together.

Russian Nootropic • BDNF Modulator

Semax: The Neuroprotective Peptide

By MeetPeptide Research Team

Last updated: March 2026

Semax is a synthetic ACTH(4-10) analog developed at Russia's Institute of Molecular Genetics. It upregulates BDNF protein levels by 1.4-fold and is approved in Russia for acute stroke therapy, cognitive disorders, and neuroprotection with over two decades of clinical use.

1.4×

BDNF Protein
Increase

ACTH

Derived from
ACTH(4-10)

Amino Acid
Heptapeptide

Background

What Is Semax?

Semax (Met-Glu-His-Phe-Pro-Gly-Pro) combines the active ACTH(4-7) fragment with a stabilizing Pro-Gly-Pro tripeptide. Unlike full ACTH, it does not significantly stimulate adrenal hormone production — its effects are concentrated on neurotrophin modulation and neuroprotection.

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BDNF & NGF Upregulation

A single dose increases BDNF protein levels 1.4-fold and TrkB phosphorylation 1.6-fold. Also induces 3-fold increase in BDNF mRNA and 2-fold increase in NGF mRNA in rat hippocampus.

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Dopamine & Serotonin

Modulates dopaminergic and serotonergic neurotransmission, enhancing motivation, focus, and mood without stimulant-like side effects.

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Cerebral Blood Flow

Improves cerebral microcirculation — a key mechanism for its approved use in acute ischemic stroke therapy in Russia.

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Neuroprotection

Activates neurotrophic factor expression after cerebral ischemia, promoting neuronal survival and recovery through BDNF/NGF and TrkB receptor pathways.

Research

What the Research Shows

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Context: Semax has been approved and used clinically in Russia since the 1990s. It has a substantial Russian literature base. The BDNF modulation data is well-replicated across multiple labs. Western clinical data remains limited.

BDNF/TrkB Expression — Hippocampus (Dolotov et al., 2006)

1.4× BDNF protein, 1.6× TrkB phosphorylation, 3× BDNF mRNA after single dose

Positive

Acute Ischemic Stroke — Russian Clinical Use

Approved for stroke therapy; improved rehabilitation timing in patients with high BDNF

Positive

Neurotrophin Gene Expression After Ischemia

Activated BDNF, NGF, and TrkB transcription in ischemic rat brain

Positive

Cognitive Enhancement — Clinical Studies

Improved attention, memory, and learning capacity in Russian clinical populations

Positive

Safety

Side Effects & Safety Profile

Nasal Irritation

Mild irritation at intranasal administration site

Mild

Adrenal Stimulation

Minimal — unlike full ACTH, does not significantly affect adrenal hormones

Minimal

Headache

Rare — reported in small number of users

Rare

Sources

Study Citations

BDNF Study

Semax, an analog of ACTH(4–10) with cognitive effects, regulates BDNF and trkB expression in the rat hippocampus

Dolotov OV, et al. · Brain Research, 2006 · PMID: 16996037

Ischemia Study

Semax and Pro-Gly-Pro Activate the Transcription of Neurotrophins and Their Receptor Genes after Cerebral Ischemia

PMC11498467 · 2024

Review

Semax — Cognitive Vitality For Researchers

Alzheimer's Drug Discovery Foundation · Comprehensive safety/efficacy review

Self-Assessment

Who Researches Semax?

This Research Is Commonly Explored By People Who...

Are interested in BDNF modulation as a cognitive enhancement strategy
Want to understand neuroprotective approaches for stroke and brain injury
Are exploring Russian-developed peptide nootropics with clinical approval
Want a nootropic that modulates neurotrophins rather than stimulant pathways

This Research May Not Be Relevant If...

You want FDA-approved nootropics — Semax is not available in the US
You prefer oral administration — Semax requires intranasal delivery
You want immediate stimulant-like effects — Semax works through neurotrophin modulation

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⚕️ Disclaimer: This is educational content, not medical advice. Always consult a healthcare provider.

Bottom Line

Key Takeaways

✅ What We Know

1.4× BDNF protein increase from single dose
Approved in Russia for stroke and cognitive disorders
Does not stimulate adrenal hormones like ACTH
Well-tolerated with minimal side effects
Over 20 years of clinical use in Russia

⚠️ What We Don't Know

Not FDA approved — no Western clinical trials
Limited long-term safety data outside Russia
Intranasal-only (no oral bioavailability)
Optimal dosing for healthy cognitive enhancement unclear

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⚠️ Disclaimer

Semax is NOT FDA approved in the United States. It is approved in Russia for stroke and cognitive disorders. This page is for educational purposes only. Not medical advice. Approved Russia Not Available US

Semax: The Neuroprotective Peptide

What Is Semax?

What the Research Shows

Side Effects & Safety Profile

Study Citations

Who Researches Semax?

This Research Is Commonly Explored By People Who...

This Research May Not Be Relevant If...

Want the Complete Protocol Guide?

Key Takeaways

🔬 Verified Research Source

Related Resources