N-Acetyl Semax: Research Overview, Mechanisms, and Current Evidence
N-Acetyl Semax is an acetylated derivative of Semax, a synthetic heptapeptide based on a fragment of the hormone ACTH (the ACTH 4-7 sequence joined to a Pro-Gly-Pro tail). The acetyl group is intended to improve stability. Semax itself has been studied in preclinical research for nootropic and neuroprotective effects and is registered in Russia as an intranasal peptide, though it has not completed Western clinical trials. Most published research uses Semax rather than the acetylated form. The information below summarizes published research for educational and research purposes only. It is not medical advice and is not guidance for use in humans.
Available for research use from our preferred vendor, Project Zero. For laboratory research use only.
How It Works (Preclinical Mechanisms)
In preclinical models, Semax has been reported to influence neurotrophic signaling, neurotransmitter systems, and pathways linked to neuroprotection.
- Reported to increase expression of brain-derived neurotrophic factor (BDNF) and related neurotrophic signaling.
- Studied for effects on dopamine, serotonin, and other monoamine systems in the brain.
- Investigated for neuroprotective and antioxidant activity, including reduced oxidative stress in injury models.
- Reported to interact with the mu-opioid receptor and modulate deubiquitination pathways in a spinal cord injury model.
Areas of Research Interest
Published studies have examined Semax and its analogs in the following research contexts. The evidence is largely preclinical, with clinical use limited mainly to Russia.
Cognition and learning
Studied in animal models for nootropic effects on memory, learning, and attention.
Neuroprotection and stroke
Investigated in ischemia and injury models, and used clinically in Russia for stroke and cognitive indications.
Neurodegeneration models
Examined in Alzheimer's disease mouse models for effects on cognition and amyloid pathology.
Mood and stress
Studied for effects on anxiety-like behaviour and the brain monoamine systems involved in stress responses.
Reported Study Parameters
For laboratory research use only. The table below reports the models and routes used in specific published studies, with sources. It describes what researchers administered in these models and is not a protocol, recommendation, or guidance for use in humans or animals. Where a primary study did not report a numeric per-kilogram dose in the indexed record, that is noted rather than estimated.
| Research Model | Dose and Route Reported | Source |
|---|---|---|
| Alzheimer's disease model (transgenic mice) | Semax and a derivative administered over the test period; specific dose reported in the source; improved cognition and reduced amyloid | Radchenko 2025·DOI |
| Early-life SSRI exposure model (rats) | Semax administered by injection on postnatal days 15 to 28; specific dose reported in the source | Glazova 2020·DOI |
| Human research | Registered in Russia as an intranasal peptide for stroke and cognitive indications; has not completed Western clinical trials and is otherwise sold as an unapproved research peptide | Vanhee 2020·DOI |
Products are supplied as lyophilized powder requiring reconstitution. For reconstitution concentration math, use the Peptide Calculator.
Latest Research (2014 to 2025)
Recent peer-reviewed literature indexed on PubMed continues to characterize how Semax works in preclinical models of cognition and neural injury.
Alzheimer's disease model (mouse)
A 2025 study reported that Semax and a derivative improved cognitive performance and reduced the number of amyloid inclusions in the cortex and hippocampus of transgenic Alzheimer's model mice across several behavioral tests. PubMed·DOI
Spinal cord injury (mouse)
A 2025 study reported that Semax promoted functional recovery after spinal cord injury in mice, acting through the mu-opioid receptor and regulating deubiquitination pathways while reducing oxidative stress. PubMed·DOI
Neurodevelopment model (rat)
A 2020 study reported that Semax reduced anxiety-like behaviour, improved learning, and normalized brain monoamine levels in rats exposed to an SSRI antidepressant early in life. PubMed·DOI
Copper binding and cell protection (in vitro)
A 2014 study reported that Semax binds copper(II) ions with high affinity and reduced copper-induced toxicity in neuroblastoma and endothelial cell lines, offering a possible mechanism for some of its neuroprotective effects. PubMed·DOI
Research Questions
How does N-Acetyl Semax relate to Semax?
N-Acetyl Semax is an acetylated derivative of Semax intended to be more stable. Most published research uses Semax itself, so findings on the parent peptide should be read with that distinction in mind.
What is the current state of human evidence?
Semax is used clinically in Russia for stroke and cognitive indications, but it has not completed clinical trials in Western regulatory systems. Outside Russia it is treated as an unapproved research peptide.
What does the available safety literature suggest?
Russian clinical use suggests reasonable tolerability of intranasal Semax, but rigorous independent safety data, especially for the acetylated derivative, are limited.
Referenced Citations
Literature indexed on PubMed.
- Radchenko, A.I., et al. (2025). The potential of the peptide drug Semax and its derivative for correcting pathological impairments in the animal model of Alzheimer's disease. Acta Naturae, 17(4), 110-120. PubMed·DOI
- Liu, R., et al. (2025). Semax peptide targets the mu opioid receptor gene Oprm1 to promote deubiquitination and functional recovery after spinal cord injury in female mice. Br. J. Pharmacol., 182(22), 5489-5516. PubMed·DOI
- Glazova, N.Yu., et al. (2020). Semax, synthetic ACTH(4-10) analogue, attenuates behavioural and neurochemical alterations following early-life fluvoxamine exposure in white rats. Neuropeptides, 86, 102114. PubMed·DOI
- Vanhee, C., et al. (2020). The occurrence of putative cognitive enhancing research peptides in seized pharmaceutical preparations. Drug Test. Anal., 12(3), 371-381. PubMed·DOI
- Tabbi, G., et al. (2014). Semax, an ACTH4-10 peptide analog with high affinity for copper(II) ion and protective ability against metal induced cell toxicity. J. Inorg. Biochem., 142, 39-46. PubMed·DOI
PeptideInfo.org provides information strictly for educational and research purposes. All referenced products are intended for laboratory and research use only and are not approved for human consumption, medical use, or self-administration. Nothing on this page constitutes medical advice. Research summaries reference literature indexed on PubMed.