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Semax & Selank: Nootropic Peptide Research Guide

Research guide for Semax and Selank nootropic peptides. Learn about their structures, mechanisms, and research applications.

8 min readUpdated Jan 2025

Semax & Selank: Nootropic Peptide Research

Semax and Selank are synthetic peptides developed in Russia and studied for their effects on the central nervous system. They represent two distinct approaches to neuropeptide research—one derived from ACTH, the other from immunoglobulin.

Peptide Profiles

Semax

PropertyDetails
OriginACTH (4-10) fragment
SequenceMet-Glu-His-Phe-Pro-Gly-Pro
Amino Acids7 (heptapeptide)
Molecular Weight~813 g/mol
FormLyophilized powder

Selank

PropertyDetails
OriginTuftsin analog
SequenceThr-Lys-Pro-Arg-Pro-Gly-Pro
Amino Acids7 (heptapeptide)
Molecular Weight~751 g/mol
FormLyophilized powder

Origins and Development

Semax Background

Semax is based on ACTH (4-10), the core fragment of adrenocorticotropic hormone. Key points:

  • Developed at the Institute of Molecular Genetics, Russian Academy of Sciences
  • ACTH (4-10) has no hormonal activity
  • Added Pro-Gly-Pro (PGP) sequence for stability
  • Studied since the 1980s

    • Selank Background

    Selank is based on tuftsin, a naturally occurring immunomodulatory peptide:

  • Original tuftsin: Thr-Lys-Pro-Arg
  • Added Pro-Gly-Pro (PGP) for stability
  • Developed at the same Russian institute
  • Studied for anxiolytic-like properties

    • The PGP Modification

    Both peptides share the Pro-Gly-Pro (PGP) C-terminal sequence, which:

  • Increases peptide stability
  • Extends biological activity
  • Improves resistance to enzymatic breakdown
  • Is itself a signaling molecule (matrikine)

    • Research Applications

    Semax Research Areas

    Neurotrophic Studies:

  • BDNF expression
  • NGF pathways
  • Neuronal survival

    • Cognitive Research:

  • Memory formation
  • Learning studies
  • Attention mechanisms

    • Neuroprotection:

  • Oxidative stress models
  • Ischemia research
  • Cellular protection

    • Selank Research Areas

    Anxiety Models:

  • GABAergic system
  • Stress response
  • Behavioral studies

    • Immune-Neural Interactions:

  • Cytokine modulation
  • Neuroimmune research
  • Inflammation models

    • Cognitive Research:

  • Memory studies
  • Learning tasks
  • Attention research

    • Proposed Mechanisms

    Semax

    Research has explored several potential mechanisms:

    SystemArea of Study
    NeurotrophinsBDNF/NGF expression
    MonoaminesDopamine, serotonin
    MelanocortinsMC receptor interactions
    AntioxidantOxidative stress protection

    Selank

    SystemArea of Study
    GABAGABAergic modulation
    MonoaminesSerotonin pathways
    EnkephalinsEndogenous opioid system
    ImmuneCytokine balance

    Reconstitution Protocol

    Semax

    Vial SizeBAC WaterConcentration
    5mg1ml5mg/ml
    10mg2ml5mg/ml

    Selank

    Vial SizeBAC WaterConcentration
    5mg1ml5mg/ml
    10mg2ml5mg/ml

    Procedure

  • Allow to reach room temperature
  • Clean stopper with alcohol
  • Add BAC water slowly along wall
  • Let dissolve (usually quick)
  • Solution should be clear
  • Store refrigerated

    • Nasal Spray Research

    Both peptides have been studied using nasal administration:

  • Rapid absorption
  • Bypasses blood-brain barrier discussion
  • Common research administration route
  • Requires proper spray device

    • Storage Guidelines

    Lyophilized

  • Freezer (-20°C): 2+ years
  • Refrigerator (2-8°C): 6-12 months
  • Keep sealed until use

    • Reconstituted

  • Temperature: 2-8°C
  • Duration: 4-6 weeks
  • Protection: Away from light
  • Never freeze

    • Comparison Table

    FeatureSemaxSelank
    ParentACTH (4-10)Tuftsin
    Primary ResearchCognitive, neuroprotectionAnxiolytic, immune
    Key SystemsBDNF, dopamineGABA, immune
    C-terminusPGPPGP

    Research Considerations

    Study Design

    When researching these peptides:

  • Consider administration route
  • Include appropriate controls
  • Time-course studies may be valuable
  • Dose-response characterization

    • Modified Versions

    Research variants include:

    VariantModification
    N-Acetyl SemaxAcetylated N-terminus
    N-Acetyl SelankAcetylated N-terminus
    Semax AmidateAmidated C-terminus

    Quality Indicators

    Expected

  • White to off-white powder
  • Clear, colorless solution
  • Quick dissolution
  • No particles

    • Problems

  • Discoloration
  • Cloudiness
  • Slow dissolution
  • Particles

    • Conclusion

    Semax and Selank represent valuable research tools for studying neuropeptide effects on cognitive function and neurochemistry. Their shared PGP modification and distinct origins provide complementary approaches to CNS research.

    *Both peptides are sold for research purposes only and are not approved for human use.*

    Frequently Asked Questions

    What is the difference between Semax and Selank?

    Semax is derived from ACTH (4-10) and primarily studied for cognitive and neuroprotective effects via BDNF pathways. Selank is derived from tuftsin and primarily studied for anxiolytic effects via GABAergic modulation. Both share the stabilizing PGP sequence.

    Why are these peptides often used as nasal sprays in research?

    Nasal administration provides rapid absorption and has been theorized to facilitate delivery to the central nervous system. It's a common research administration route for CNS-targeted peptides.

    What does N-Acetyl Semax/Selank mean?

    N-Acetyl versions have an acetyl group attached to the N-terminus (amino end). This modification may affect stability, activity duration, or biological properties compared to the standard versions.

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