Description
Semax is a synthetic heptapeptide developed at the Institute of Molecular Genetics of the Russian Academy of Sciences in Moscow. Structurally, it is an analog of the N-terminal ACTH(4-10) fragment with a C-terminal Pro-Gly-Pro extension that significantly extends stability and half-life. The sequence is Met-Glu-His-Phe-Pro-Gly-Pro.
Across more than three decades of Russian research, Semax has demonstrated effects on learning, memory, attention and neuroprotective pathways in preclinical and clinical studies. The compound is on Russia’s list of vital essential medicines and has been officially used there for stroke, cognitive disorders and neurological conditions since 2011.
The main mechanism in research models is the rapid and pronounced upregulation of BDNF (Brain-Derived Neurotrophic Factor) and its receptor TrkB in the hippocampus and cortex. A single intranasal application produces a 3-fold increase in BDNF mRNA expression and a 1.4-fold increase in BDNF protein in the hippocampus in animal models. Secondarily, serotonergic, dopaminergic and cholinergic systems are modulated. In research setups, Semax is used intranasally due to its size and polarity.
In recent studies (2025), Semax was investigated in Alzheimer models and showed significant reductions in amyloid plaques. The research data base focuses primarily on Russian publications, which should be considered when evaluating.
This variant is a ready-to-use nasal spray: 10mg of Semax dissolved in 5 ml saline and 0.4 ml bacteriostatic water (5.4 ml in total), nothing to mix yourself. One spray (0.1 ml) delivers about 185 mcg. A bottle lasts for about 50 sprays. It is made fresh once you place your order and ships as an express item. As a powder for reconstitution, Semax remains available in vials.
This information is for research and educational purposes only. No medical recommendations.
Risks & Safety
Semax is considered very well tolerated per study reports. Across more than three decades of Russian preclinical and clinical research, the compound has consistently been described as low in side effects.
Observed in research and user reports:
- Intranasal irritation: since Semax is used intranasally due to its size and polarity, mild burning, dryness or irritation of the nasal mucosa is the most common observation.
- Stimulation: occasional reports of mild restlessness, head pressure or shifted sleep, particularly with late-day use, as the compound addresses stimulating and cognitive pathways.
- Russian data base: the majority of studies come from Russian publications, which makes independent assessment of the safety profile more difficult.
- Limited long-term data: robust long-term human studies outside the Russian research context are largely lacking.
This classification does not replace medical advice. Risk and responsibility for any actual use lie entirely with the buyer.
Studies
- Semax regulates BDNF and trkB expression in the rat hippocampus - Brain Research 2006: Classical study on BDNF upregulation after Semax application.
- Semax binds specifically and increases BDNF protein in rat basal forebrain - Journal of Neurochemistry 2006: Binding specificity and BDNF mechanism.
- The peptide semax affects the expression of genes related to the immune and vascular systems in rat brain focal ischemia - BMC Genomics 2014, Medvedeva et al: Genome-wide transcriptome study on Semax effects after focal ischemia.
