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Peptide Profile

Semax

ACTH(4-10) analogue · Meksidol · Semax NA

Semax (MEHFPGP) is a synthetic heptapeptide derived from the N-terminal fragment of ACTH(4-7) with a C-terminal Pro-Gly-Pro extension to enhance stability, developed at the Institute of Molecular Genetics of the Russian Academy…

Neuro & CognitiveAdvisory Vote: FavorableResearch Only
Used forcognitive
Half-life
20–30 minutes (intranasal)
Routes
intranasal, subcutaneous

Educational research information — not medical advice. Review primary sources and consult a qualified professional before any decision.

Educational research tools — not medical advice.

Overview

What Semax is

About Semax

Semax is believed to upregulate brain-derived neurotrophic factor (BDNF) and other neuroprotective factors, enhancing neuronal survival and synaptic plasticity. It modulates the dopaminergic and serotonergic systems, contributing to its reported effects on mood and focus. Its mechanism of action differs from classical stimulants — it does not act on adrenergic receptors and does not produce typical stimulant tolerance or dependence patterns.

Semax (MEHFPGP) is a synthetic heptapeptide derived from the N-terminal fragment of ACTH(4-7) with a C-terminal Pro-Gly-Pro extension to enhance stability, developed at the Institute of Molecular Genetics of the Russian Academy of Sciences as a nootropic and neuroprotective agent, and registered in Russia as a pharmaceutical for cognitive disorders, ischemic stroke, and cerebrovascular insufficiency. Semax modulates BDNF and NGF expression in neural tissue, influences dopaminergic, serotonergic, and cholinergic activity, and is proposed to exert neuroprotective effects in ischemic conditions by reducing neuroinflammation and supporting neuronal survival following cerebrovascular events. Human clinical studies published in peer-reviewed Russian neurology journals (Zh Nevrol Psikhiatr Im S.S. Korsakova) — indexed in PubMed — have examined semax in ischemic stroke patients and cerebrovascular insufficiency, reporting improvements in neurological outcomes and cognitive function; these studies document genuine clinical investigation, though no blinded Western RCTs or external replications exist. Semax is approved in Russia for clinical use in ischemic stroke and cognitive disorders; it has no FDA approval and is not approved in any Western jurisdiction, and while the Russian clinical evidence reflects substantial investigational work, the absence of independently conducted Western trials limits confidence in translating the reported findings to broader clinical recommendations. Semax is available in both standard and N-acetyl semax (N-acetyl-Semax) formulations; N-acetyl semax is considered to have enhanced lipophilicity and potentially extended biological activity, though direct comparative clinical data between formulations is limited. Intranasal administration — semax nasal spray — is the primary delivery route in Russian clinical practice and the form used in the published clinical research, offering rapid mucosal absorption and CNS delivery. Semax nasal spray formulations at 0.1% and 1% concentrations have been used in the Russian clinical program for stroke and cognitive disorder indications; subcutaneous injection is more common in international research compound contexts.

Women's Health

Semax's human trials are in ischemic stroke rehabilitation and cognition, not mood or women's-health indications; the largest trial's mixed-sex cohort was not analyzed by sex. There is no human pregnancy/lactation safety data.

Semax Benefits & Research Areas

BDNF and VEGF upregulation supporting neuroplasticityneuroprotection and stroke recovery — Russian clinical approvalcognitive performance and focus enhancement via dopaminergic modulationnasal spray administration — CNS access via olfactory epithelium

Research Signals

Commonly researched in the context of

High StressPoor SleepIrregular Sleep

Population research notes

18–2930s40s50+

These signals reflect research interest areas, not treatment indications.

Pharmacokinetics

Semax half-life

Why no half-life is shown

Semax is used intranasally and is broken down in plasma within minutes. No reliable human plasma half-life has been established, so no decay curve is shown.

The Research

What the evidence says about Semax

Regulatory Status

Availability Status
Research Only
FDA Status
Advisory Vote: Favorable
Effective Date
July 24, 2026

Russian ACTH 4-7 neuropeptide analog. Approved pharmaceutical nasal spray in Russia. Not FDA-approved. Not on FDA 503A bulks list. Unscheduled in US. Sold as research chemical.

Regulatory status reflects publicly available information and may change. This is not legal or medical advice.

Semax Side Effects & Safety Considerations

Research-use compound with limited human data. Evidence strength varies — see the Evidence section.

No established clinical contraindications. This is an investigational compound with limited human data and has not been evaluated by the FDA for safety in this context. Consult a qualified clinician.

Consult a qualified healthcare professional before making any health decisions. This information is educational only and does not constitute medical advice.

Known Interactions

1 noted
Synergistic1
Emerging

Research suggests Semax and Selank may produce complementary cognitive and stress-modulating effects when combined. Semax is studied for BDNF upregulation and cognitive enhancement, while Selank is studied for anxiolytic and immune-regulatory activity — distinct mechanisms with potential overlap in neuroprotective signaling.

Seredenin SB & Voronin MV (2009) Anxioselective activity of selank peptide. Eksp Klin Farmakol; Dolotov OV et al. (2006) Semax affects cognitive function and BDNF expression. Peptides

These interactions reflect published research and are provided for educational purposes only. This is not medical advice. Consult a qualified healthcare professional before combining any compounds or medications.

Third-party testing data

8 verified COAs

Median tested purity

99.2%

Median tested purity of 99.2% across 8 verified third-party lab COAs (interquartile range 98.9%99.7%), as reported by the independent testing labs below. PeptideBase reports these lab-published figures and does not itself test, endorse, or certify any product.

Independent labs
Freedom Diagnostics, Janoshik Analytical
Most recent test
July 2026

PeptideBase provides educational research tools and provider discovery. It does not provide medical advice, diagnosis, treatment, prescribing guidance, or dosing instructions. Consult a qualified healthcare professional before making health decisions.

Certificates of Analysis

Cross-vendor verified21 COAs on record for Semax

PeptideBase reports these lab-published figures and does not itself test, endorse, or certify any product. Confirmed by lab results were matched against the issuing laboratory's own records — either the lab served the document, or its own hosted copy matches ours byte for byte. For every other result the badge states what is known about the lab: that it can be checked and no result is recorded yet, that it can't be checked, or that we have not reviewed it.

PeptideBase provides educational research tools and provider discovery. It does not provide medical advice, diagnosis, treatment, prescribing guidance, or dosing instructions. Consult a qualified healthcare professional before making health decisions.

Community Experience

What people report about Semax

n=49high confidence

Self-reported, anecdotal experiences aggregated from public Reddit discussions — community sentiment, not clinical evidence or medical advice.

Outcome distribution

41%improved
Improved
20 · 41%
Mixed
12 · 24%
No clear effect
15 · 31%
Worse
2 · 4%

Outcomes by goal · improved % · reports

Focus & cognition32% improved · 25 reports
Mental clarity70% improved · 10 reports
Mood & wellbeing29% improved · 7 reports
Energy & vitality50% improved · 4 reports

Side effects people mention

Counts are mentions across reports, not incidence rates.

Emotional blunting3
Application site reaction2
Overstimulation2
Anxiety1
Injection site reaction1
Insomnia1
Mood changes1

Most reported

What they wish they'd known

  • Response to Semax varies enormously between individuals, making personal outcomes highly unpredictable.12×thread 1thread 2thread 3
  • Effects, if they appear at all, may only become apparent gradually or in retrospect over weeks.7×thread 1thread 2thread 3
  • Route of administration appeared to meaningfully influence whether users felt any effect.6×thread 1thread 2thread 3
  • Emotional or mood-related side effects such as blunting or grumpiness surprised some users.6×thread 1thread 2thread 3

Based on 49 community reports · Updated

Frequently Asked Questions — Semax

Semax (MEHFPGP) is a synthetic heptapeptide derived from the N-terminal fragment of ACTH(4-7) with a C-terminal Pro-Gly-Pro extension to enhance stability, developed at the Institute of Molecular Genetics of the Russian Academy of Sciences as a nootropic and neuroprotective agent, and registered in Russia as a pharmaceutical for cognitive disorders, ischemic stroke, and cerebrovascular insufficiency. Semax modulates BDNF and NGF expression in neural tissue, influences dopaminergic, serotonergic, and cholinergic activity, and is proposed to exert neuroprotective effects in ischemic conditions by reducing neuroinflammation and supporting neuronal survival following cerebrovascular events.

BDNF and VEGF upregulation supporting neuroplasticity, neuroprotection and stroke recovery — Russian clinical approval, cognitive performance and focus enhancement via dopaminergic modulation, nasal spray administration — CNS access via olfactory epithelium.

Research on Semax primarily documents effects related to BDNF and VEGF upregulation supporting neuroplasticity and neuroprotection and stroke recovery — Russian clinical approval and cognitive performance and focus enhancement via dopaminergic modulation and nasal spray administration — CNS access via olfactory epithelium. These are areas covered in preclinical and clinical literature — individual response varies and effects depend on context of use.

For Semax, its FDA status is Advisory Committee Recommended, and it is designated for research use only. Regulatory status reflects publicly available information and may change. This is not legal or medical advice.

133 providers in the directory currently offer Semax.

Across 45 research vendors tracked on PeptideBase, Semax has a median price of about $4.37 per mg, typically ranging $3.52–$5.50 per mg. This reflects research-use vendor pricing, not clinical or prescription costs.

Semax is featured in the following research stacks on PeptideBase: Dihexa + Semax: Memory & Cognitive Performance, Selank + Semax: Cognitive Enhancement.

Access

How to get Semax

Market Pricing

45 vendors
$3.52/mgBudget
$4.37/mgMedian
$5.50/mgPremium
$3.52
$4.37
$5.50

Price per mg varies by quantity, vendor type, and formulation. Research use only.

Data verified August 2026 · Semax price intelligence

Where to buy Semax

133 providers
92 Clinics5 Telehealth2 Pharmacies33 Online Vendors1 Physician1 mid164 in stock4 on request

Research stacks

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Commonly stacked with

Questions to ask your provider

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Last updated

Cite this page

Data last updated August 26, 2026

Free to reference and republish with attribution to PeptideBase. Choose a format:

PeptideBase. (2026). Semax — Per-mg Price Benchmark. Retrieved September 11, 2026, from https://peptidebase.io/peptides/semax

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