Written by the Core Power Peptides Research Team — biochemists and laboratory specialists compiling and verifying peptide research data. Learn about our quality standards →
Semax began as a fragment of adrenocorticotropic hormone — ACTH 4-10 — stripped of hormonal activity but retaining neurotrophic signaling. Three decades of Russian and Eastern European neuroscience research later, the parent compound is approved for clinical use in Russia for stroke and cognitive impairment, while its doubly-modified derivative has become the more stable form used across current research protocols.
N-Acetyl Semax Amidate: What the Modifications Change
Semax Amidate (N-Acetyl Semax Amidate) is a modified neuropeptide derived from adrenocorticotropic hormone (ACTH 4-10) that has been extensively studied in Russian and Eastern European neuroscience research for over three decades. The amidate modification (C-terminal amidation) confers greater proteolytic stability compared to the parent Semax molecule, extending its biological half-life and potentially improving CNS bioavailability. N-acetylation at the N-terminus further enhances blood-brain barrier penetration in research models.
Semax and its derivatives are among the most studied nootropic peptides in preclinical literature, with documented effects on BDNF expression, dopaminergic tone, and neuroprotection under oxidative stress conditions. The compound is approved for medical use in Russia under the brand name Semax® for stroke and cognitive impairment indications.
Mechanism of Action
Semax Amidate operates through several converging neuropeptide pathways:
- BDNF Upregulation: Increases brain-derived neurotrophic factor mRNA and protein expression in hippocampal and prefrontal regions — the primary mechanism implicated in cognitive and mood research
- Dopaminergic Modulation: Enhances dopamine release and receptor sensitivity in prefrontal and limbic circuits, relevant for attention and executive function research
- Serotonergic Effects: Influences 5-HT1A receptor activity, contributing to documented anxiolytic and mood-related effects
- Neuroprotection: Attenuates oxidative stress and neuroinflammation in ischemia and excitotoxicity models through BDNF-TrkB signaling
- ACTH Receptor Agonism: Stimulates melanocortin receptors (MC4R) that mediate learning, attention, and stress adaptation pathways
- NGF Enhancement: Increases nerve growth factor expression, supporting neuronal differentiation and survival research
Preclinical and Clinical Research Data
Cognitive and Memory Research
Multiple Russian clinical studies and preclinical models have documented Semax’s effects on cognition:
- Significant improvement in spatial memory and working memory tasks in rodent models at doses of 50–200 µg/kg
- Enhanced learning acquisition rate in Morris water maze protocols
- Improved attention and processing speed metrics in human clinical trials for ischemic stroke (registered in Russia)
- BDNF increases of 100–200% over baseline observed in hippocampal tissue within 24 hours of administration in rodent studies
Neuroprotection Research
- Demonstrated 40–60% reduction in infarct volume in middle cerebral artery occlusion (MCAO) rodent stroke models
- Attenuation of glutamate-induced excitotoxicity in cortical cell cultures
- Preservation of neuronal viability under H₂O₂-induced oxidative stress conditions
Anxiety and Stress Models
- Reduced anxiety-like behavior in elevated plus maze and open field tests in rodents
- Attenuated HPA axis hyperactivation under chronic restraint stress
- Normalized corticosterone responses in repeated stress paradigms
Dosage Reference for Research
| Research Context |
Typical Dose |
Route |
Notes |
| In vitro |
1–100 nM |
Media |
BDNF upregulation studies |
| Rodent (acute) |
50–200 µg/kg |
Intranasal or SC |
Cognitive and stroke protocols |
| Rodent (chronic) |
50–100 µg/kg/day |
Intranasal |
14–28 day protocols |
| Human (Russian clinical) |
200–600 µg/day |
Intranasal |
Stroke, cognitive impairment |
Research reference only. Not dosing guidance for human use.
Semax vs. Semax Amidate — Key Differences
| Parameter |
Semax |
N-Acetyl Semax Amidate |
| Sequence modification |
None (base peptide) |
N-acetyl + C-terminal amide |
| Proteolytic stability |
Moderate |
Higher (resistant to enzymatic cleavage) |
| BBB penetration |
Moderate (intranasal) |
Enhanced (N-acetylation increases lipophilicity) |
| Research potency |
Base reference |
Generally ~2–5x more potent per equivalent dose |
| Available formats |
Powder, spray |
Powder, spray |
Where to Source Semax Amidate for Research
Key criteria when evaluating research peptide suppliers for Semax Amidate:
- HPLC purity ≥99% with published certificate of analysis
- Mass spectrometry confirmation of correct modification (N-acetyl + amidate)
- Sterility and endotoxin testing if intended for in vivo protocols
- Lyophilized format for long-term −20°C storage stability
- Spray formulation availability for intranasal delivery protocols
Semax Research Products
HPLC Verified
Semax 10mg
Purity: 99%+ HPLC
Format: Lyophilized Powder
Testing: Third-Party COA
$95
Buy Now
HPLC Verified
N-Acetyl Semax Amidate 20mg
Purity: 99%+ HPLC
Format: Lyophilized Powder
Modification: N-Acetyl + Amidate
$130
Buy Now
HPLC Verified
N-Acetyl Semax Amidate 30mg
Purity: 99%+ HPLC
Format: Lyophilized Powder
Modification: N-Acetyl + Amidate
$175
Buy Now
Frequently Asked Questions
What do the N-acetyl and amidate modifications actually do?
C-terminal amidation confers proteolytic stability, extending biological half-life relative to unmodified Semax. N-acetylation at the N-terminus increases lipophilicity, which enhances blood-brain barrier penetration in research models. Together they produce a compound generally characterized as roughly 2–5× more potent per equivalent dose than the parent peptide.
How does Semax relate to Selank?
Both emerged from Russian neuropeptide research and both are available in N-acetyl amidate forms, but they derive from different parent molecules and engage different pathways — Semax from ACTH 4-10, acting largely through BDNF and dopaminergic signaling, and Selank from tuftsin, acting through GABAergic modulation.
Which administration route is standard in research protocols?
Intranasal delivery is standard across both rodent protocols and Russian clinical use, reflecting the compound’s CNS targets. Subcutaneous administration appears in some acute rodent work.
Provided for educational and scientific reference. Semax Amidate is not approved for human use in most jurisdictions outside Russia; material from Core Power Peptides is supplied for in vitro and laboratory research exclusively and carries no medical claims.
