Semax is a synthetic peptide studied for cognitive and neuroprotective
endpoints. As with Selank, the shape of its evidence base is as important as the
findings themselves.
Chemical identity & structure.
Semax is a synthetic heptapeptide. It is based on a short fragment of
adrenocorticotropic hormone (the ACTH 4–10 region) with an added Pro-Gly-Pro
sequence that improves stability and extends its duration of action. Crucially,
Semax has no hormonal (corticotropic) activity — the fragment it is based on
was chosen for neuro-active properties, not hormonal ones. It was developed by
Russian researchers.
Mechanism of action.
The most consistently reported mechanism is upregulation of brain-derived
neurotrophic factor (BDNF) and related neurotrophic signaling, which is the
basis for its reported neuroprotective and cognitive effects. The literature
also describes modulation of monoamine (dopamine, serotonin) systems and effects
on the metabolism of endogenous regulatory peptides. These mechanisms are
reported but not definitively settled.
Key research findings.
Research reports neuroprotective effects in models of ischemic injury and
reported effects on attention, memory-related endpoints, and stress resilience.
In Russia, Semax has been used clinically in the context of stroke and cognitive
indications.
The research / citation base.
Like Selank, Semax's literature is predominantly Russian, with limited
independent Western replication. It is used clinically in Russia but is **not
approved by the FDA or EMA**. The neuroprotective and nootropic claims rest on a
research base that has not been broadly validated by Western-standard trials.
Human clinical trial data
In the clinical study by Gusev et al. (2018) of 110 patients after ischemic stroke, the semax+ subgroups received two treatment courses of semax separated by a break (PubMed).
Quality & sourcing notes.
A batch-specific COA should confirm identity by mass spectrometry (the Pro-Gly-Pro
extension affects the expected mass) and report HPLC purity. Confirm the COA
describes Semax and not a related ACTH-fragment peptide.
*Research-use note: Educational summary of published research. Semax is not
FDA/EMA-approved; this is research context only and not medical advice.*