What is Semax?
Semax is a synthetic heptapeptide derived from adrenocorticotropic hormone (ACTH), specifically the 4-10 fragment with an added Pro-Gly-Pro tripeptide at the C-terminus. Developed at the Institute of Molecular Genetics of the Russian Academy of Sciences, Semax has been studied extensively for its nootropic and neuroprotective properties.
Unlike full ACTH, Semax lacks hormonal activity while retaining neurotrophic effects. It has been approved in Russia and several Eastern European countries for various neurological applications, making it one of the most well-characterized nootropic peptides available for research.
Development History
Russian Origins
Timeline:
Approved Indications (Russia):
ACTH Fragment Science
ACTH (39 amino acids) has multiple functional regions:
| Fragment | Function |
|---|---|
| 1-24 | Full adrenocortical activity |
| 4-10 | Nootropic activity (no hormonal effect) |
| 4-7 | Core melanocortin binding |
Semax uses the 4-10 fragment plus stabilizing modifications.
Mechanism of Action
Neurotrophic Effects
BDNF Modulation:
NGF Enhancement:
Neurotransmitter Systems
Dopaminergic:
Serotonergic:
Glutamatergic:
Melanocortin System
Semax retains melanocortin receptor activity:
Peptide Profile
| Property | Details |
|---|---|
| Full Name | Semax (ACTH 4-10 + PGP) |
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro |
| Amino Acids | 7 (heptapeptide) |
| Molecular Weight | 813.93 g/mol |
| Purity | 99%+ (HPLC verified) |
| Form | Lyophilized powder or nasal solution |
| Half-life | ~3-5 minutes (parent compound) |
The short half-life relates to the parent peptide; metabolites may have longer activity.
Research Applications
Cognitive Enhancement Studies
Memory Research:
Attention Studies:
Neuroprotection Research
Ischemic Models:
Neurodegeneration:
Stress and Adaptation
HPA Axis Research:
Semax vs Selank: Comparison
Both are Russian-developed nootropic peptides with distinct profiles:
| Aspect | Semax | Selank |
|---|---|---|
| Origin | ACTH fragment | Tuftsin analog |
| Primary Effect | Cognitive enhancement | Anxiolytic |
| Neurotrophins | BDNF focus | BDNF + NGF |
| Mood Effects | Secondary | Primary |
| Energy | Stimulating | Calming |
| Best For | Focus, learning | Anxiety, stress |
Choosing Between Them:
See our Selank guide for comparison.
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Dosage Protocols in Research
Nasal Administration
Semax is commonly administered intranasally:
Advantages:
Standard Concentrations:
Reconstitution (Lyophilized)
| Vial Size | Bacteriostatic Water | Concentration |
|---|---|---|
| 5mg | 5ml | 1mg/ml |
| 10mg | 10ml | 1mg/ml |
Procedure:
Use our peptide calculator for precise measurements.
Semax
30mg • 99%+ Purity
$34.99
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Research Dosing Ranges
Nasal Administration (Literature):
Subcutaneous (Research):
Storage Guidelines
Lyophilized Form
Reconstituted/Solution
See our storage guide.
Enhanced Variants
N-Acetyl Semax (NASA)
Modified version with acetyl group:
N-Acetyl Semax Amidate (NASA Amidate)
Further modification:
Safety Profile in Research
Clinical Experience (Russia)
Documented Profile:
Reported Effects:
Research Considerations
Frequently Asked Questions
What makes Semax different from ACTH?
Semax contains only the 4-10 fragment of ACTH plus a stabilizing PGP tail. This fragment retains neurotrophic properties while lacking the hormonal (adrenocortical) activity of full ACTH. Semax does not stimulate cortisol production or affect adrenal function.
Is Semax a stimulant?
Semax is not a classical stimulant. It modulates neurotrophins and neurotransmitters to enhance cognitive function without the typical stimulant profile (jitteriness, cardiovascular effects, crash). Users describe it as a "clean" focus enhancement rather than stimulation.
How does Semax compare to Selank?
Semax is more cognitively activating (focus, learning, memory) while Selank is more anxiolytic (calming, stress-reducing). Semax is better for concentration tasks; Selank for anxiety reduction. Some researchers study them together. See our Selank article.
What is the best administration route?
Nasal administration is most common due to rapid absorption and direct CNS access. Subcutaneous injection is also used in research. Nasal provides faster onset while subcutaneous may offer different pharmacokinetics.
How should Semax be stored?
Lyophilized Semax should be stored at -20°C for maximum stability. Reconstituted solutions should be refrigerated at 2-8°C and used within 4-6 weeks. Pre-made nasal solutions follow manufacturer guidelines.
Does Semax affect hormones?
Unlike full ACTH, Semax does not significantly affect cortisol or other adrenal hormones. Research has confirmed the lack of hormonal activity, which is a key advantage of this specific fragment.
Related Resources
Conclusion
Semax represents one of the most well-researched nootropic peptides, with decades of clinical use in Russia and extensive scientific literature. Its unique profile—cognitive enhancement without hormonal effects—makes it valuable for neuroscience research.
For researchers studying cognitive enhancement, neuroprotection, or neurotrophic factors, Semax offers a well-characterized tool with established safety data.
Explore our Semax products and nasal spray options.
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This article is for informational purposes only. Semax is sold for research purposes and is not FDA approved. All research should be conducted in accordance with applicable regulations.
