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
| Protocol | Dose | Frequency | Duration |
|---|---|---|---|
| Cognitive Enhancement | 200-400 mcg | 2-3x daily | 10-20 days, cycle |
| Neuroprotection | 400-600 mcg | 2-3x daily | 10-14 days |
| N-Acetyl Semax (NASA) | 100-200 mcg | 1-2x daily | 10-20 days |
| Amidate (NA-Semax-Amidate) | 100-200 mcg | 1-2x daily | 10-20 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