Now reading Entry 076 / 102 Last revised Jan 22, 2026 32 sources 1 comparisons Methodology →
A specimen of the Cognitive drawer Drawer E · Cognitive

Semax

Research Only

A synthetic heptapeptide analogue of ACTH(4-7) with a C-terminal Pro-Gly-Pro extension, developed by Russian researchers and approved in Russia since ~1997 for stroke, cognitive impairment, and optic nerve disorders. Demonstrates nootropic and neuroprotective effects through BDNF/NGF upregulation, dopaminergic and serotonergic modulation, and anti-inflammatory mechanisms. Extensive Russian clinical research supports efficacy, particularly in stroke rehabilitation, though Western independent replication remains limited.

ACTH(4-7)PGP · Methionyl-Glutamyl-Histidyl-Phenylalanyl-Prolyl-Glycyl-Proline · MEHFPGP

Research evidence
Moderate

8 human studies

Preclinical
75%
Clinical
25%

Based on 32 cited sources

Evidence Score67/100
Emerging / moderate
Research Depth58/100
Mechanism74/100
Plausibility77/100
Global Coverage62/100
Community Experience68/100
Effectiveness43/100

clinically demonstrated · low confidence

Demonstrated effect magnitude — not a recommendation or safety claim.

Research Depth 58: best human tier is multiple controlled clinical trials — Gusev 2018 (29798983, n=110 post-stroke, BDNF + Barthel) plus a placebo-controlled fMRI study (32342318, n=52) and older controlled optic-nerve trials (10741256, 11569188) — so 1A scores at the "controlled / multiple observational" band rather than a clean RCT; 1B held low ("some concerns": Russian trials lack clear randomization/blinding detail); total human N ~300-500 (1C ~8); stroke outcomes are direct (1D); 1E credits an extensive replicated preclinical program. Mechanism 74: well-mapped BDNF/NGF->TrkB neuroplasticity and transcriptome-wide RNA-Seq cascades (32580520, 34201112), a recent independent target identification via mu-opioid receptor with USP18 knockdown (40692165) lifting 2A toward the binding+functional+knockdown band, dose-response across in-vivo models (16362768), all confirmed in mammalian models. Plausibility 77: for stroke the mechanism->BDNF surrogate->Barthel clinical chain is supported end-to-end, fully coherent with neurotrophin biology, with melanocortin/ neurotrophic class analogy; minor deduction for multi-system (cognition, optic, ADHD) breadth. Global Coverage 62: historically a single Russian cluster (Kurchatov/Pirogov) but now genuinely replicated by independent groups in China (40692165), Indonesia, and Italy, ~30-60 studies across 4-6 countries, with Russian regulatory approval (4D=10). Community Experience 68: sustained 7+ year nootropic-community use across multiple venues, broadly consistent reported themes, only minor non-serious adverse reports. Effectiveness basis clinical (low confidence): Gusev stroke trial shows accelerated functional recovery / Barthel improvement and controlled optic-nerve trials show visual-function gains — moderate effect on hard patient-relevant outcomes, superior to placebo/rehab-alone but no head-to-head vs standard stroke care, and the entire efficacy base is Russian-origin with risk-of-bias concerns and no Western replication.

Scored June 2026 How we rate →
~
Evidence Level
moderate
Not approved for human use by any regulatory agency
Limited human clinical trial data
Consult a healthcare provider before use
Not FDA Approved WADA Prohibited
Identity
SCALE · 1:1 N-TERMINUS C-TERMINUS 7 AA · 813.93 Da
Also Known As
ACTH(4-7)PGP • Methionyl-Glutamyl-Histidyl-Phenylalanyl-Prolyl-Glycyl-Proline • MEHFPGP
Class
Heptapeptide
Length
7 amino acids
Mol. weight
813.93 Da
Sequence
MEHFPGP
Molecular Structure
M
E
H
F
P
G
P
Hydrophobic
Polar
Positive
Negative

Semax has a complex, multi-target mechanism of action that distinguishes it from traditional nootropics. Unlike its parent ACTH molecule, Semax does not stimulate cortisol release, making it safe for long-term neurological use.

How It Works (Simplified)

Semax acts as a “brain fertilizer and protector” through several complementary pathways:

Neurotrophin Boost

Rapidly increases BDNF and NGF expression within minutes of administration, supporting learning, memory, neuronal survival, and recovery from injury.

Neurotransmitter Modulation

Activates dopamine and serotonin systems in striatum and frontal cortex, enhancing attention, motivation, and mood without depleting neurotransmitter stores.

Anti-Inflammatory

Suppresses pro-inflammatory cytokines (IL-1, IL-6, TNF-alpha) and chemokines following brain injury, protecting neurons from secondary damage.

Modulates hundreds of genes involved in neurotransmission, immune response, and cell survival, producing sustained benefits through transcriptional changes.

Important Limitations

  • Most research originates from Russian institutions with limited Western independent replication
  • Many primary studies published only in Russian, creating language barriers for verification
  • Historical clinical trials may not meet current Western GLP/GCP standards
  • Human pharmacokinetics and optimal dosing not fully characterized by Western standards
  • No FDA or EMA regulatory pathway has been pursued
i. BDNF/NGF Neurotrophin Pathway · Neuroprotection & Cognition
Semax (intranasal)CNS penetrationGene expression activationBDNF / NGF mRNA rapidly upregulated (within ~30 min)TrkB/TrkA receptor upregulationEnhanced neuroplasticityMemory consolidation
ii. Dopaminergic/Serotonergic Pathway · Attention & Mood
SemaxStriatum and frontal cortex5-HIAA ↑ (25-180%)Dopamine system modulationImproved attention, motivation, mood
iii. Anti-Inflammatory Pathway · Neuroprotection
Brain injuryInflammatory cascadeSemax interventionIL-1a, IL-1b, IL-6, TNF-alpha mRNACcl3, Cxcl2 (chemokines)Reduced secondary neuronal damage
Mechanism Rapid upregulation of BDNF and NGF expression in hippocampus and cortex
Established 12 direct studies
Benefit shown to enhance cognitive function and memory
Evidence Level
Moderate
3 Human
8 Animal
4 In Vitro
Mechanism Suppression of pro-inflammatory cytokines (IL-1, IL-6, TNF-alpha) and chemokines following ischemia
Established 8 direct studies
Benefit shown to provide neuroprotection and reduce secondary brain damage after stroke
Evidence Level
Moderate
2 Human
6 Animal
3 In Vitro
Mechanism Modulation of dopaminergic and serotonergic neurotransmission in striatum and frontal cortex
Supported 5 direct studies
Benefit appears to improve attention, motivation, and mood regulation
Evidence Level
Low
1 Human
5 Animal
2 In Vitro
Mechanism Stimulation of neurotrophin expression in retina and optic nerve tissue
Supported 4 direct studies
Benefit may protect and restore optic nerve function
Evidence Level
Low
2 Human
3 Animal
2 In Vitro
Mechanism Confidence
Established
Supported
Emerging
Evidence Level
High
Moderate
Low
Very Low

Reported positives

  • Improved focus and mental clarity frequently reported
  • Reduced brain fog and enhanced cognitive performance
  • Mood improvement and reduced anxiety noted
  • Nasal administration convenient and non-invasive

Reported negatives

  • Effects short-lived requiring frequent redosing
  • Hair loss reported by some long-term users
  • Irritability and overstimulation at higher amounts
  • Product quality varies between suppliers

“Popular nootropic in r/Nootropics and r/Peptides. Russian-approved drug with growing Western interest.”

Self-reported, unverified accounts — not clinical evidence and no substitute for the cited research. Anecdotes are prone to selection bias and placebo effects.

Phase 01 1
Week 1-2

Based on preclinical and clinical data: Rapid BDNF/NGF upregulation begins within 30 minutes of intranasal administration. In stroke patients, early intervention shows greatest benefits. Dopamine and serotonin modulation observed.

PMID:16996037
Phase 02 2
Week 2-4

In stroke rehabilitation trials, BDNF levels increased significantly and functional recovery (Barthel scores) improved over 2-4 weeks. Anti-inflammatory effects reduce secondary brain damage. Clinical trials showed improved attention and cognitive function.

PMID:29798983
Phase 03 3
Week 4-8

Russian protocols typically use 10-14 day treatment courses. Long-term effects and optimal duration not characterized by Western standards. Some conditions may require repeated courses.

PMID:16362768
Phase 04 4
Week 8+

Long-term maintenance protocols not well-established. Russian clinical practice suggests periodic treatment courses rather than continuous administration. Human pharmacokinetics not fully characterized.

Research-based observations

This timeline reflects observations from published clinical and preclinical studies. Individual responses may vary significantly. This is not a guarantee of effects or a dosing schedule. Consult qualified healthcare providers for personalized guidance.

Good Signs (6 indicators)
White lyophilized powder
Complete dissolution in bacteriostatic water
Clear, colorless solution after reconstitution
Certificate of analysis showing >98% purity
HPLC verification of sequence
Mass spectrometry confirmation (813.93 Da)
Warning Signs (5 indicators)
Off-white or slightly discolored powder
Slow dissolution time
No third-party testing verification
Purity between 95-98%
Unclear manufacturing source
Bad Signs (6 indicators)
Yellow or brown discoloration
Visible particles after reconstitution
Cloudy solution
No certificate of analysis
Unusual odor
Compromised seal or packaging
Positive quality indicator
Requires evaluation
Potential quality issue

For Research Evaluation Only

These quality indicators are general guidelines based on typical peptide characteristics. Professional laboratory testing (HPLC, mass spectrometry) provides definitive quality verification. This checklist is for initial visual evaluation only.

Synergistic
Compatible
Caution
Avoid

Complementary Russian regulatory peptides - Semax provides nootropic/neuroprotective effects via BDNF while Selank offers anxiolysis via GABA. Common clinical combination in Russia.

Both Russian bioregulator peptides with different CNS targets - Semax for acute neuroprotection via BDNF, epithalon for cellular longevity via telomeres.

Both have neuroprotective properties - Semax via BDNF/NGF upregulation, BPC-157 via multiple CNS repair mechanisms. May have complementary neuroprotective effects.

Semax has immunomodulatory effects alongside nootropic actions; Ta1 is primarily immunomodulatory. Different primary mechanisms with potential immune synergy.

Both promote tissue repair - Semax in CNS via neurotrophins, TB-500 systemically via actin regulation. Different primary targets.

Research Note: Interaction data is based on published literature, mechanistic understanding, and theoretical considerations. Most peptide combinations lack direct clinical study. This information is for educational purposes only and does not constitute medical advice. Always consult qualified healthcare providers.

This dossier synthesizes available evidence from peer-reviewed literature, regulatory documents, and clinical trial registries. Evidence strength ratings follow a modified GRADE approach.

For complete methodology details, see our Methodology page.

Important Disclaimer

This dossier is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider before making health decisions.

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