Prof. PeptideProf. Peptide

Semax

Cognitive & NootropicResearch-Grade

Last reviewed: September 20, 2026

Quick Facts

What it is
A lab-made neuropeptide built from the ACTH(4-7) fragment of adrenocorticotropic hormone with a Pro-Gly-Pro tail — studied for cognition, focus, and neuroprotection, and described in research papers as non-hormonal.
How it's taken
Intranasal drops (preferred), or subcutaneous injection
Half-life
Not established (~2–3 minutes in plasma is often quoted, no study found); BDNF effects persist 24+ hours in rats
Typical research dose
Community-reported (unverified): 600–1,200 mcg/day. Registered label: 500–5,000 mcg/day, 3–5 days — see Dosing section
Research status
Not FDA-approved; a prescription drug in Russia/Ukraine — sold elsewhere for research use only.
On this page
  1. 1.Where to source Semax
  2. 2.What is Semax?
  3. 3.How does Semax work?
  4. 4.What is Semax used for?
  5. 5.How long does Semax take to work?
  6. 6.How is Semax dosed?
  7. 7.How is Semax administered?
  8. 8.What does Semax stack well with?
  9. 9.What are the side effects of Semax?
  10. 10.Does Semax interact with other drugs?
  11. 11.How should Semax be stored?
  12. 12.What are the limitations of Semax research?
  13. 13.Semax FAQ
  14. 14.References
  15. 15.Published Studies
  16. 16.In the News

Where to source Semax

Outside Russia/Ukraine, Semax is sold by specialty research peptide vendors as research-grade material. Quality varies — choose vendors that provide third-party testing certificates (HPLC purity, mass spectrometric identity confirmation). The vendors highlighted below have been vetted — including N-Acetyl Semax variants and nasal format options.

Capstone Peptides50% off
Professor's Pick

Accumark Labs · digital COAs

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Amino Club40% off

ILS Laboratories · batch COAs

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Peptide Partners10% off
Professor's Pick

Kovera, Chromate and BioRegen · certificates checked at each lab

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Glacier Aminos10% off

Batch-traceable COAs · cold-chain shipping

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Compare prices across 54 vendors

Also stocking Semax

Modern Aminos, Mytide Lab, Oasis Labs, Peptide Basix — each carries a current price row for this compound.

Compare all 54 vendors stocking Semax

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What is Semax?

Semax is a synthetic heptapeptide (Met-Glu-His-Phe-Pro-Gly-Pro, one-letter code MEHFPGP), sometimes marketed as the “Russian nootropic peptide,” developed in the 1980s at the Institute of Molecular Genetics of the Russian Academy of Sciences. It combines the ACTH(4-7) fragment of adrenocorticotropic hormone with a Pro-Gly-Pro stabilizing tail that protects against rapid enzymatic degradation. Despite a short plasma half-life commonly reported at roughly 2–3 minutes, though no published pharmacokinetic study or label has been identified establishing this figure for Semax, it produces long-lasting nootropic and neuroprotective effects through upregulation of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) in the hippocampus and cortex. It is approved in Russia for ischemic stroke recovery and cognitive impairment but has no FDA or EMA approval. Research papers describe it as a non-hormonal, noncorticotropic ACTH analogue; no study measuring cortisol in people given Semax was found. Often paired with Selank as the Semax-Selank blend for balanced cognitive enhancement plus calm. New to peptide research? Start with the basics

Reported benefits:

  • Cognitive enhancement: improved focus, memory, and mental clarity
  • BDNF and NGF upregulation in hippocampus and cortex
  • Neuroprotection: reduces ischemic damage in animal stroke models
  • Modulates serotonergic and dopaminergic systems
  • Described as non-hormonal (no human cortisol study found); no addiction or withdrawal reported
  • Russian-approved for stroke recovery and cognitive impairment

Common research dose: Community-reported (unverified) cognitive-enhancement dose: 600–1,200 mcg/day intranasally via 0.1% solution, typically split across the day, over 10–14 day cycles. The cited stroke trials used different, clinically-supervised regimens — 12–18 mg/day for 5–10 days, or 6 mg/day across two 10-day courses — see the Dosing section for the literature-vs-community comparison.

Where to buy: PP maintains a vetted list of peptide vendors with verified discount codes. See Verified Discount Codes for current options.

How does Semax work?

Semax's nootropic effects are attributed to BDNF and NGF upregulation in the hippocampus and cortex; in rat studies the neurotrophic changes unfold over hours and persist 24+ hours. A plasma half-life of 2–3 minutes is often quoted, but no pharmacokinetic study was found for it. Concurrent monoamine system modulation (serotonin, dopamine) is linked to the mood and motivation effects. Research papers describe Semax as a non-hormonal, noncorticotropic ACTH analogue. No study measuring cortisol or HPA-axis activity in people given Semax was found.

  1. BDNF Upregulation [1]. Single intranasal Semax doses produce a 1.4-fold increase in BDNF protein and a 3-fold increase in BDNF mRNA in the rat hippocampus within hours, with effects persisting 24+ hours. BDNF supports neuronal survival, synaptic plasticity, and memory formation.
  2. NGF and TrkB Modulation [1]. Concurrent with BDNF effects, Semax increases nerve growth factor (NGF) levels in frontal cortex and hippocampus, plus 1.6-fold increase in TrkB receptor phosphorylation. This neurotrophic cascade drives the long-lasting cognitive effects despite the peptide's short half-life.
  3. Monoamine System Modulation [2]. Intranasal Semax increases serotonin in the hippocampus and cortical regions and modulates dopamine signaling within 30 minutes. These effects underlie the mood, motivation, and attention benefits reported clinically.
  4. Enkephalinase Inhibition [3]. Semax (like Selank) inhibits enzymes that degrade endogenous enkephalins (IC50 ~10 μM), prolonging the activity of the body's natural opioid peptides. This contributes to mild anxiolytic and stress-buffering effects.
  5. Described as Non-Hormonal [4]. Semax was designed from the ACTH(4-10) fragment, and later research papers describe it as a non-hormonal, noncorticotropic ACTH analogue. No study measuring cortisol or hypothalamic-pituitary-adrenal (HPA) axis activity in people given Semax was found.

What is Semax used for?

Semax's research evidence base spans ischemic stroke recovery (a Russian controlled comparative study — the approved indication), BDNF mechanism studies (foundational animal work), cognitive performance under stress (students, pilots, sustained-attention tasks), optic nerve disorders (approved Russian indication), and stroke plasma BDNF in humans. Most clinical evidence is Russian-language, single-center, and not replicated in large Western trials.

  1. Ischemic Stroke Recovery [5]. Gusev et al. 1997 (PMID 11517472) compared 30 Semax-treated hemispheric ischemic stroke patients against 80 patients on conventional therapy, reporting some improvement in the rate of neurological-function recovery. The abstract does not state randomization, and no "Phase 3" or "multi-center" designation appears in the paper itself — this is a single-center controlled comparative study, not a randomized multicenter trial. Russian approval for this indication is based on this and related evidence.
  2. BDNF and Cognitive Function [1]. Foundational mechanism studies (Dolotov et al. 2006, Ashmarin et al. 1995) established the BDNF-mediated nootropic mechanism in animal models, including improved learning and memory in passive avoidance and Morris water maze paradigms.
  3. Cognitive Performance Under Stress. Russian studies in students under exam load, pilots in simulated flight stress, and operators on sustained-attention tasks consistently report preserved or improved performance on vigilance and working memory.
  4. Optic Nerve Disorders. Approved indication in Russia. Semax 1% is used for optic nerve atrophy and ischemic optic neuropathy with demonstrated improvement in visual function.
  5. Stroke Plasma BDNF [7]. Gusev et al. 2018 (PMID 29798983) examined 110 ischemic-stroke patients divided into semax-treated and untreated subgroups (6,000 mcg/day for 10 days, 2 courses with a 20-day interval) — an observational comparison, not a randomized trial. Semax treatment was associated with higher plasma BDNF, and higher BDNF correlated with better Barthel-index recovery.

How long does Semax take to work?

Semax effects develop on two timescales. Subjective cognitive effects (focus, alertness, motivation) typically onset 20–40 minutes after intranasal dosing, peak around 1–2 hours, and last 4–6 hours — no trial or label has been identified establishing this timing. Neurochemical effects (BDNF mRNA upregulation, TrkB phosphorylation) are measurable within hours and continue building over days of consistent dosing. Most users report cumulative benefits over the first 3–7 days of a typical 10–14 day cycle.

Subjective cognitive effects (focus, alertness, motivation) typically onset 20–40 minutes after intranasal dosing, peak around 1–2 hours, and last 4–6 hours. Neurochemical effects (BDNF mRNA upregulation, TrkB phosphorylation) are measurable within hours and continue building over days of consistent dosing. Most users report cumulative benefits over the first 3–7 days of a typical 10–14 day cycle. In clinical trials, stroke recovery effects are measured over weeks of treatment.

How is Semax dosed?

Two of the cited human studies report actual doses used — Gusev et al. 1997 [5] (stroke) and Gusev et al. 2018 [7] (stroke, BDNF/Barthel outcome) — and a third source, the Russian Ministry of Health-registered package insert [8], sets the approved label ranges by indication. The cognitive-enhancement figure widely repeated outside Russia is not derived from any of these and is labelled below as community-reported.

Prof. Peptide reports what trials established and what research communities practice, labelled separately. Neither is a recommendation.

Need to calculate a dose?

Use the Prof. Peptide dosage calculator for accurate reconstitution and dosing math.

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What the cited literature administered

  1. Acute ischemic stroke, Gusev et al. 1997 [5]. Human controlled comparative study (30 Semax-treated vs 80 conventional-therapy controls; abstract does not state randomization). The most effective doses reported were 12 mg/day for moderate-severity stroke (5-day course) and 18 mg/day for severe stroke (10-day course) — not the 10–14-day course length this page previously stated, and the abstract does not specify a 6–12 hour onset-to-treatment window.
  2. Ischemic stroke, Gusev et al. 2018 [7]. Observational comparison (semax+ vs semax- subgroups, not randomized), n=110. Regimen: 6,000 mcg/day for 10 days, repeated as a second course after a 20-day interval.
  3. Registered package insert [8] (Peptogen JSC, 0.1% solution). General/cognitive-disorder indication: single dose 200–2,000 mcg, daily dose 500–5,000 mcg, for 3–5 days (extendable to 14 with medical supervision). Optic nerve disorders: 2–3 drops per nostril, 2–3× daily (600–900 mcg/day), for 7–10 days. This is Evidence Level: Approved-label, not an RCT dose.
  4. 1% solution (stroke indication) [8]. The registered 1% formulation is specified for acute ischemic stroke; the 0.1% formulation is not indicated for that use. No fixed mcg/day figure for the 1% product beyond the Gusev trial doses above has been identified in the label.

Community-reported practice (unverified)

  1. Cognitive enhancement. 600–1,200 mcg/day intranasally via 0.1% solution, typically 1–2 drops per nostril, 2–3 times daily — not from a cited trial, though it falls inside the registered label's broader 500–5,000 mcg/day general-use range [8].
  2. Subcutaneous research dosing (unverified). 250–1,000 mcg/kg per dose; typical fixed dose 200–600 mcg per injection — a route not covered by the registered label, which is intranasal-only.
  3. Cycle length (community convention). 10–14 days, repeated every 1–3 months — longer than the label's default 3–5 day course but within its extendable-to-14-days ceiling [8].

Semax has three available variants. Standard Semax (0.1%/1% solution) has the most clinical data. Vendors state that N-Acetyl Semax is 2–3x as potent and longer-acting, and that N-Acetyl Semax Amidate (NA-Semax-A) is 100–1,000× more potent per microgram, used at 50–100 mcg. No study was found for these potency figures. The N-Acetyl variants are less studied.

The Prof. Peptide dosage calculator converts between milligram figures and syringe units for a given reconstitution; it performs the arithmetic and does not set a schedule.

How is Semax administered?

Semax is administered intranasally (preferred — fastest CNS access via nose-to-brain transport) or by subcutaneous injection. The 0.1% solution is standard for cognitive enhancement; the 1% solution is used for stroke protocols. Reported protocols keep dosing out of the evening — potential overstimulation and sleep disturbance. For SC technique, see the syringes and injection technique guide.

  1. Route. Intranasal (preferred) or subcutaneous injection.
  2. Time of day. Morning and early afternoon in reported protocols (evening dosing carries potential overstimulation and sleep disturbance).
  3. Intranasal technique. Tilt head slightly back. Apply 1–2 drops per nostril. Blowing the nose within 30 minutes clears the dose before it absorbs.
  4. Reconstitution (lyophilized). For 0.1% solution: 5 mg vial + 5 mL bacteriostatic water = 1 mg/mL (~50 mcg per drop in standard nasal dropper).
  5. Higher concentrations. For 1% solution (stroke protocols): 10 mg vial + 1 mL = 10 mg/mL.
  6. Missed dose. Reported practice skips and resumes at the next scheduled dose. Effects are cumulative across days — missing one dose has minimal impact.
  7. Cycle structure. Standard 10–14 days, then break of 1–3 months before next cycle.

Timing context. A plasma clearance of 2–3 minutes is often quoted for Semax, but no pharmacokinetic study or label was found that establishes it. In rat studies, BDNF gene expression changes unfold over hours and persist 24+ hours. Community reports describe morning dosing for daytime focus and disrupted sleep after evening doses.

AspectReported
FrequencyCommunity-reported (unverified): 2–3× daily during a 10–14 day course for cognitive-enhancement use. Registered label [8]: 3–5 days (extendable to 14) for general use. The cited stroke trials used different regimens — 12–18 mg/day for 5–10 days (Gusev 1997 [5]) or 6 mg/day, 2 courses of 10 days (Gusev 2018 [7])
Best time of dayMorning and early afternoon — avoid evening (overstimulation, sleep disruption)
FoodNo fasting required
Route choiceIntranasal preferred for cognitive applications; SC alternative for research
Half-lifeNot established (~2–3 minutes plasma is often quoted, no study found); BDNF effects persist 24+ hours in rats
Steady-stateCumulative cognitive effects reported to build over 3–7 days of consistent dosing — community practice, not trial-derived for the cognitive-enhancement use case

Reconstitution math (subcutaneous use). Water volume sets concentration: a lower volume yields a higher concentration and a smaller syringe draw for a given mg amount, and the reverse for a higher volume. Semax research vials are typically 5 mg. Standard 0.1% intranasal solution uses 5 mL recon to give 1 mg/mL. For SC dosing, the table below shows alternative recon volumes. All units below are measured on a U-100 insulin syringe (100 units = 1 mL). The table assumes a 5 mg vial.

BAC waterConcentration100 mcg dose300 mcg dose600 mcg dose1.2 mg dose
1 mL5 mg/mL2 units6 units12 units24 units
2 mL2.5 mg/mL4 units12 units24 units48 units
5 mL1 mg/mL10 units30 units60 unitsn/a*

*Draw exceeds standard 100-unit insulin syringe capacity at this reconstitution volume — would require split injections or a lower reconstitution volume.

Units vs mcg. At a 5 mg vial, each unit drawn delivers 50 mcg of Semax at 1 mL reconstitution, 25 mcg at 2 mL, and 10 mcg at 5 mL. For a primer on reading insulin syringes and choosing the right barrel size, see our guide on syringes and injection technique.

Common question: Does Semax nasal spray work?

What does Semax stack well with?

Semax's canonical pairing is Selank — the gold-standard cognitive-anxiolytic combination. BDNF/dopamine (Semax) + GABA/serotonin (Selank) creates balanced nootropic effect — run as a Semax-Selank combination or dosed separately. Caffeine pairs anecdotally for amplified focus. BPC-157 and L-Theanine are compatible. Adequate sleep is essential — Semax effects are weakened by sleep deprivation.

  1. Selank (Semax-Selank Stack). The gold standard pairing. Semax for cognitive enhancement (BDNF, dopamine) + Selank for anxiolysis (GABA, serotonin) creates balanced nootropic effect. Most experienced users dose Semax in morning, Selank in afternoon/evening, or combined as the Semax-Selank stack.
  2. Caffeine. Anecdotally combined for amplified focus, though no controlled studies on the combination.
  3. BPC-157. BPC-157 combined for general health/recovery support; no direct interaction.
  4. L-Theanine. Added to take edge off any potential overstimulation.
  5. Adequate sleep. Essential. Semax effects are weakened by sleep deprivation. Bedtime hygiene matters more than dose timing.

What are the side effects of Semax?

Decades of Russian pharmaceutical use of semax plus extensive preclinical toxicological studies show no serious adverse events, no addiction, and no withdrawal. No study measuring cortisol or HPA-axis activity in people given semax was found. The most common issues are local (nasal irritation) or due to overstimulation (resolves with dose reduction). Long-term continuous daily use beyond standard 10–14 day cycles has limited published data.

Common (most users)

  1. Mild nasal dryness or irritation. Intranasal route only.
  2. Mild headache. Especially first doses; resolves with continued use.
  3. Slight overstimulation. Mild irritability at higher doses; resolves with dose reduction.

Less common (moderate)

  1. Sleep disturbance. If dosed late in the day — reason to avoid evening dosing.
  2. Transient mild dizziness or nausea.
  3. Mild fatigue after end of dosing window.

Serious (rare)

  1. No serious adverse events reported in published Russian clinical literature spanning 30+ years.
  2. No addictive potential or withdrawal syndrome documented.
  3. Long-term safety beyond 14-day cycles in healthy individuals not formally established.

Decades of Russian pharmaceutical use of semax plus extensive preclinical toxicological studies show no serious adverse events, no addiction, and no withdrawal. No study measuring cortisol or HPA-axis activity in people given semax was found. The most common issues are local (nasal irritation) or due to overstimulation (resolves with dose reduction). Long-term continuous daily use beyond standard 10–14 day cycles has limited published data.

Does Semax interact with other drugs?

Semax's relevant interactions are with MAOIs and SSRIs (Semax modulates serotonergic systems — combine cautiously, no documented serious interactions but theoretical serotonin elevation risk), other nootropic stacks (generally compatible with caffeine, choline donors, racetams — but additive overstimulation possible), and direct ACTH or cortisol-modulating drugs (no interaction expected since Semax does NOT affect HPA axis). No major drug-drug interactions reported.

  1. MAOIs and SSRIs. Semax modulates serotonergic systems; combine cautiously. No documented serious interactions but theoretical serotonin elevation risk.
  2. Other nootropic stacks. Generally compatible with caffeine, choline donors, racetams, but additive overstimulation possible.
  3. Direct ACTH or cortisol-modulating drugs. No interaction study was found; research papers describe Semax as non-hormonal (noncorticotropic).
  4. No major drug-drug interactions reported in published research.

How should Semax be stored?

  1. Lyophilized (powder) form: Store at -20°C for long-term storage; refrigerate at 2–8°C for short-term.
  2. Reconstituted nasal solution: 2–8°C, refrigerated, is standard practice once dissolved. Prof. Peptide has not identified a manufacturer label, published study, or lab document establishing how long reconstituted research-grade Semax remains stable — this page does not state a duration as fact.
  3. Reconstitution uses bacteriostatic water for injection (BAC water). Swirl gently — do not shake.
  4. The reconstituted solution is never frozen.
  5. Semax is stored protected from light, in the original carton or amber dropper bottle.
  6. A solution that is cloudy, discolored, or contains particles is discarded.

What are the limitations of Semax research?

Semax is approved in Russia and Ukraine as a prescription medication for ischemic stroke recovery, cognitive impairment, and optic nerve disorders. It is NOT FDA-approved in the US or EMA-approved in Europe. Most clinical evidence comes from Russian-language journals not replicated in large randomized Western trials. The mechanism of action remains incompletely characterized — BDNF upregulation is well-replicated in animal models but lacks equivalent human mechanistic studies. NOT WADA-prohibited.

Semax is approved in Russia and Ukraine as a prescription medication for ischemic stroke recovery, cognitive impairment, and optic nerve disorders. It is NOT FDA-approved in the United States or EMA-approved in Europe. Most clinical evidence comes from Russian-language journals that have not been replicated in large randomized Western trials.

The mechanism of action remains incompletely characterized. The most consistent finding (BDNF upregulation) is well-replicated in animal models but lacks equivalent human mechanistic studies. Effects on cognitive performance in healthy individuals are documented in Russian literature but are largely absent from Western peer-reviewed research.

Research-grade material sold outside Russian pharmaceutical channels is intended for laboratory use only. Purity and potency vary by vendor; a third-party certificate is the only check on either.

The World Anti-Doping Agency does not currently include Semax on the prohibited list, but this status may change as the peptide attracts more attention in performance contexts.

Semax FAQ

Is Semax FDA-approved?

No. Semax is approved as a prescription medication in Russia and Ukraine for stroke recovery, cognitive impairment, and optic nerve disorders. It is not FDA-approved in the United States or EMA-approved in Europe. Outside Russia, Semax is sold as a research-grade peptide.

How is Semax different from Selank?

Both are Russian heptapeptides developed at the same institute with similar Pro-Gly-Pro stabilization. Semax is derived from ACTH(4-7) and primarily targets BDNF and dopaminergic systems — best for cognitive enhancement, focus, and stroke recovery. Selank is derived from tuftsin and primarily acts on GABA and serotonergic systems — best for anxiolysis without sedation. They are commonly stacked together as the Semax-Selank blend or dosed separately. See the Semax vs Selank comparison for protocol differences.

Why does the half-life seem so short?

A plasma clearance of 2–3 minutes is often quoted, but no published pharmacokinetic study or label was found that establishes this figure. Rat studies report BDNF and NGF gene expression changes that unfold over hours after a single dose and persist 24+ hours. No study was found that ties dose frequency to these signaling windows.

Will Semax raise my cortisol?

Research papers describe Semax as a non-hormonal, noncorticotropic ACTH analogue. No study measuring cortisol or HPA-axis activity in people given Semax was found.

Should I use intranasal or subcutaneous?

Intranasal is preferred for cognitive applications because partial nose-to-brain transport via olfactory pathways gives faster and more efficient CNS access. Subcutaneous works systemically but loses some of the direct CNS targeting advantage. Most published Russian protocols use intranasal.

What about N-Acetyl Semax variants?

Vendors state that N-Acetyl Semax is 2–3x as potent and longer-acting than standard Semax, and that N-Acetyl Semax Amidate (NA-Semax-A) is 100–1,000× more potent per microgram, used at 50–100 mcg vs the 200–600 mcg standard range. No study was found for these potency figures. Less clinical data exists on these variants.

How long until I see results?

Subjective effects (focus, motivation, alertness) onset within 20–40 minutes of the first dose. Cumulative cognitive benefits typically build over 3–7 days of consistent dosing. In clinical protocols, stroke recovery effects are measured over 10–14 days of treatment.

Where can I buy Semax?

Outside Russia/Ukraine, Semax is sold by specialty research peptide vendors as research-grade material. Quality varies — choose vendors that provide third-party testing certificates (HPLC purity, mass spectrometric identity confirmation). PP maintains a list of vetted vendors with verified discount codes — see Verified Discount Codes .

References

  1. Dolotov OV, Karpenko EA, Inozemtseva LS, et al. Semax, an analog of adrenocorticotropin (4-10), binds specifically and increases levels of brain-derived neurotrophic factor protein in rat basal forebrain. J Neurochem. 2006;97(suppl 1):82-86. https://pubmed.ncbi.nlm.nih.gov/16635254/
  2. Eremin KO, Kudrin VS, Saransaari P, et al. Semax, an ACTH(4-10) analogue with nootropic properties, activates dopaminergic and serotoninergic brain systems in rodents. Neurochem Res. 2005;30(12):1493-500. https://pubmed.ncbi.nlm.nih.gov/16362768/
  3. Wikipedia. Semax. https://en.wikipedia.org/wiki/Semax
  4. Ashmarin IP, Nezavibatko VN, Levitskaya NG, et al. Design and investigation of an ACTH(4-10) analog lacking D-amino acids and hydrophobic radicals. Neurosci Res Commun. 1995;16:105-12.
  5. Gusev EI, Skvortsova VI, Miasoedov NF, et al. Effectiveness of Semax in the acute period of hemispheric ischemic stroke (a clinical and electrophysiological study). Zh Nevrol Psikhiatr Im S S Korsakova. 1997;97(6):26-34. https://pubmed.ncbi.nlm.nih.gov/11517472/
  6. Romanova GA, Silachev DN, Shakova FM, et al. Neuroprotective and antiamnesic effects of Semax during experimental ischemic infarction of the cerebral cortex. Bull Exp Biol Med. 2006;142(6):663-6. https://pubmed.ncbi.nlm.nih.gov/17603664/
  7. Gusev EI, Martynov MY, Kostenko EV, Petrova LV, Bobyreva SN. The efficacy of semax in the treatment of patients at different stages of ischemic stroke. Zh Nevrol Psikhiatr Im S S Korsakova. 2018;118(3.2):61-68. https://pubmed.ncbi.nlm.nih.gov/29798983/
  8. RLSNET. Semax (Семакс), package insert — nasal drops 0.1%. Registration holder: Peptogen JSC. https://www.rlsnet.ru/drugs/semaks-5420

Published Studies

Plain-English summaries of the peer-reviewed studies behind the claims above. Click any title to read the source paper.

Brain Research / ScienceDirect · 2006Paywalled
Semax, an Analog of ACTH(4-10) with Cognitive Effects, Regulates BDNF and trkB Expression in the Rat Hippocampus →

Dolotov OV, Karpenko EA, Inozemtseva LS, et al.

A foundational mechanistic study establishing how Semax enhances cognitive function at the molecular level. A single intranasal application produced a 1.4-fold increase in BDNF protein levels, 1.6-fold increase in trkB receptor phosphorylation, and 3-fold increase in BDNF mRNA in the rat hippocampus — with treated animals showing significant increases in conditioned learning responses. This study established the BDNF/trkB pathway as the key mechanism behind Semax's cognitive effects.

PMC / BMC Genomics · 2014Open Access
Semax Peptide Affects Expression of Genes Related to the Immune and Vascular Systems in Rat Brain Focal Ischemia — Genome-Wide Transcriptional Analysis →

Medvedeva EV, Dmitrieva VG, Povarova OV, et al.

A genome-wide study examining how Semax protects the brain during stroke. Semax modulated over 1,500 genes, primarily in the immune and vascular systems. Rather than acting purely on neurons, Semax enhanced the activity of immune cells (mobilizing microglia and leukocytes) and promoted vascular gene expression to support blood flow restoration.

Genes (MDPI) / PMC · 2020Open Access
Novel Insights into the Protective Properties of Semax Peptide at the Transcriptome Level Following Cerebral Ischaemia-Reperfusion in Rats →

Dmitrieva VG, et al.

RNA sequencing identified 394 differentially expressed genes in Semax-treated vs. saline-treated animals at 24 hours post-stroke. Semax suppressed inflammation-related gene expression while simultaneously activating neurotransmission-related genes — providing a compelling mechanistic explanation for Semax's clinical effectiveness in stroke rehabilitation.

Acta Naturae · 2025Open Access
The Potential of the Peptide Drug Semax and Its Derivative for Correcting Pathological Impairments in an Animal Model of Alzheimer's Disease →

Radchenko AI, Kuzubova EV, Apostol AA, et al.

One of the most recent Semax studies, examining its potential in Alzheimer's disease using transgenic mice. Both Semax and a derivative improved cognitive function across multiple behavioral tests. Histological analysis showed reduced amyloid plaque burden in the cortex and hippocampus of treated animals — Semax not only improved cognition but appeared to directly reduce the pathological protein aggregation that defines Alzheimer's disease.

Cognitive & NootropicBDNFRussian-ApprovedResearch-Grade

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Semax vs Selank

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