Cognitive & NootropicWell-Tolerated

Semax

Also known as: ACTH 4-10 Analog, Semax Acetate, Heptapeptide Semax

A synthetic peptide analog of ACTH (4-10) developed in Russia for cognitive enhancement, neuroprotection, and stroke recovery. One of the most studied nootropic peptides.

Half-Life

Short (minutes to hours)

Typical Dose

200-600 mcg

Frequency

1-3x daily

Routes

Intranasal

Overview

Semax is a synthetic heptapeptide developed at the Institute of Molecular Genetics of the Russian Academy of Sciences in the 1980s. It is based on a fragment of Adrenocorticotropic Hormone (ACTH) - specifically the 4-10 amino acid sequence - but has been modified to remove hormonal activity while retaining neurological benefits.

In Russia, Semax is an approved prescription medication for:

  • Stroke recovery
  • Cognitive impairment
  • Peptic ulcers
  • Optic nerve disease

Key Characteristics

  • Origin: Synthetic analog of ACTH (4-10) fragment
  • Classification: Nootropic/neuroprotective peptide
  • Sequence: Met-Glu-His-Phe-Pro-Gly-Pro
  • Approved Status: Prescription medication in Russia/Ukraine
  • Unique Feature: No hormonal (corticotropic) activity

The PGP Modification

The key to Semax's effectiveness:

  • Natural ACTH 4-10: Met-Glu-His-Phe-Pro-Gly-Pro
  • The C-terminal Pro-Gly-Pro extension increases stability
  • Protects against rapid degradation
  • Extends duration of action
  • Enhances brain penetration

Mechanism

Semax operates through multiple neurological pathways, making it a true multimodal nootropic.

Primary Mechanisms

1. BDNF Upregulation

Brain-Derived Neurotrophic Factor enhancement:

  • Increases BDNF expression significantly
  • Promotes neuroplasticity
  • Supports learning and memory
  • Enhances synaptic connections
  • May promote neurogenesis

2. NGF and GDNF Modulation

Other neurotrophic factors:

  • Nerve Growth Factor (NGF) increase
  • Glial cell line-Derived Neurotrophic Factor (GDNF) support
  • Comprehensive neurotrophic support
  • Neuroprotection from multiple angles

3. Dopamine and Serotonin Modulation

Neurotransmitter effects:

  • Increases dopamine and serotonin turnover
  • Modulates enkephalin system
  • Does NOT cause hormonal ACTH effects
  • Subtle mood and motivation enhancement

4. Anti-Inflammatory (CNS)

Neuroinflammation reduction:

  • Reduces pro-inflammatory cytokines in brain
  • Protects against inflammatory damage
  • May benefit neurodegenerative conditions
  • Supports recovery from brain injury

5. Oxidative Stress Protection

Antioxidant actions:

  • Increases antioxidant enzyme activity
  • Reduces lipid peroxidation
  • Protects neurons from oxidative damage
  • Supports mitochondrial function

Research

Research Note: Semax has extensive Russian research and clinical use spanning decades, though Western clinical trials are limited.

Stroke Recovery (Approved Indication)

Russian Clinical Studies

Extensive use in stroke treatment:

  • Accelerates neurological recovery
  • Reduces disability scores
  • Improves cognitive function post-stroke
  • Safe profile in acute settings

Mechanism in Stroke

  • Reduces infarct size in animal models
  • Promotes angiogenesis in damaged areas
  • Supports neuronal survival
  • Enhances rehabilitation outcomes

Cognitive Enhancement

Healthy Individuals

Research suggests:

  • Improved attention and focus
  • Enhanced memory formation
  • Better cognitive flexibility
  • Increased mental stamina

Cognitive Impairment

Studies in impaired populations show:

  • Improved cognitive test scores
  • Enhanced memory recall
  • Better executive function
  • Potential benefit in early dementia

ADHD Research

2025 Studies

Emerging research indicates:

  • Improved attention metrics
  • Reduced hyperactivity in some measures
  • Potential alternative to stimulants
  • Further research needed

Optic Nerve Protection

Russian-approved for optic nerve disease:

  • Glaucoma support
  • Optic neuritis recovery
  • May protect retinal ganglion cells
  • Administered via nasal spray

Anxiety (Comparison to Selank)

While Semax is primarily cognitive:

  • Some anxiolytic properties
  • Less pronounced than Selank
  • Complementary when combined
  • Different primary indications

Dosing

Disclaimer: Semax is not FDA-approved in the United States. It is approved in Russia for medical use. All dosing information is for research reference only.

Research Protocols

ProtocolDoseFrequencyDuration
Cognitive Enhancement200-400 mcg2-3x daily10-20 days, cycle
Neuroprotection400-600 mcg2-3x daily10-14 days
N-Acetyl Semax (NASA)100-200 mcg1-2x daily10-20 days
Amidate (NA-Semax-Amidate)100-200 mcg1-2x daily10-20 days

Forms Available

Standard Semax

  • Original formulation
  • Most studied
  • Moderate potency

N-Acetyl Semax (NASA)

  • Acetylated version
  • Enhanced stability
  • Potentially more potent
  • Popular in nootropic community

NA-Semax-Amidate

  • Further modified
  • Claimed enhanced potency
  • Limited research
  • Used at lower doses

Administration Notes

Intranasal (Most Common)

  • Standard route in Russia
  • Excellent brain penetration
  • Spray or drops into nostril
  • Alternate nostrils
  • Best absorbed on empty stomach

Subcutaneous

  • Alternative route
  • May have more systemic effects
  • Some prefer for consistency

Cycling Recommended

  • Typical: 10-20 days on, 10-20 days off
  • Prevents tolerance development
  • Maintains BDNF response
  • Russian protocols typically cycled

Storage

  • Store in refrigerator
  • Nasal spray: room temperature okay for short term
  • Protect from light
  • Use within recommended timeframe

Pharmacokinetics

Absorption

  • Intranasal: Rapid absorption across nasal mucosa
  • Bypasses blood-brain barrier partially
  • Peak effects: 15-60 minutes

Distribution

  • Crosses into CNS
  • Concentrates in brain regions
  • Wide tissue distribution

Metabolism

  • Metabolized by peptidases
  • PGP extension provides stability
  • Active metabolites may contribute

Elimination

  • Relatively rapid clearance
  • Multiple daily dosing needed
  • No accumulation observed

Comparison: Semax vs Selank

| Feature | Semax | Selank | |---------|-------|--------| | Primary Effect | Cognitive | Anxiolytic | | BDNF Effect | Strong | Moderate | | Anxiety Reduction | Mild | Strong | | Stimulating | Yes (mild) | No | | Focus Enhancement | Primary | Secondary | | Best For | Mental performance | Anxiety + mild cognition |

Combining Semax and Selank

Many users combine both:

  • Complementary mechanisms
  • Semax for cognition
  • Selank for anxiety/stress
  • Can use same intranasal delivery
  • Stagger doses slightly

Safety

Known Side Effects

Common (generally mild)

  • Nasal irritation (intranasal route)
  • Mild headache (initial use)
  • Lightheadedness (transient)

Rare

  • Hair loss reported (reversible)
  • Insomnia if taken late
  • Irritability at high doses

Contraindications

Use with caution if:

  • History of seizures
  • Severe hypertension
  • Pregnancy or breastfeeding
  • Active psychosis

Generally safe for:

  • Most healthy adults
  • Those seeking cognitive enhancement
  • Stroke recovery (with medical supervision)

Safety Note: Semax has an excellent safety profile in Russian clinical use spanning decades. No serious adverse events commonly reported.

Drug Interactions

  • Limited documented interactions
  • Caution with other stimulating compounds
  • May enhance effects of other nootropics
  • Generally safe with most medications

Monitoring

Subjective Assessment

  • Cognitive performance tracking
  • Mood and motivation monitoring
  • Sleep quality assessment
  • Side effect logging

No Required Labs

  • No specific blood tests required
  • Optional: baseline cognitive testing
  • Consider periodic reassessment of effects

Regulatory

Current Status

| Region | Status | |--------|--------| | Russia/Ukraine | Approved prescription medication | | United States | Not FDA-approved; research chemical | | European Union | Not approved; research use | | WADA | Not prohibited |

Legal Considerations

  • Legal to purchase in most jurisdictions
  • Not controlled substance
  • Available from peptide suppliers
  • Prescription only in Russia/CIS countries

Clinical Outlook

Semax represents sophisticated Russian peptide research:

  • Decades of clinical use and safety data
  • Limited Western research interest (so far)
  • Growing popularity in nootropic community
  • Potential for broader therapeutic applications
  • May see more Western research in future

References

[1] Ashmarin IP, et al.. Regulatory peptides in cognitive processes. Neuroscience and Behavioral Physiology (2002)
[2] Gusev EI, et al.. Semax in prevention of disease progress and development of exacerbations in patients with cerebrovascular insufficiency. Zhurnal Nevrologii i Psikhiatrii (2005)
[3] Dolotov OV, et al.. Semax, an analog of ACTH(4-10) with cognitive effects, regulates BDNF and trkB expression. Brain Research (2006)
[4] Nootropic Research Review. Semax: Mechanisms, Clinical Use, and Cognitive Applications. Neuropeptide Research (2025)