Semax
Cognitive
In short
- A synthetic heptapeptide derived from ACTH(4-10), stripped of hormonal activity — it does not raise cortisol.
- A registered medicine in Russia for stroke and cognitive indications; not approved in the US, EU, or UK.
- Plasma half-life is minutes, but reported effects last hours, attributed to downstream BDNF changes.
- Most of the clinical literature is Russian, not independently replicated, and difficult to appraise from outside.
- The intranasal route is the studied one; injection is a community practice without supporting data.
Structure
How it works
Semax is a fragment of adrenocorticotropic hormone with a Pro-Gly-Pro tail added for stability. The ACTH(4-10) fragment retains neurotropic activity without the steroidogenic effect of the full hormone, so it does not stimulate cortisol.
The main described mechanism is rapid upregulation of BDNF and NGF expression in the hippocampus and cortex, plus modulation of the dopaminergic and serotonergic systems. BDNF changes are reported within an hour of intranasal administration in animal work, which is the usual explanation for effects outlasting the peptide itself.
What the research shows
Russian clinical studies report benefit in ischaemic stroke, transient ischaemic attack, cognitive impairment, and optic nerve conditions. These underpin its Russian registration.
Animal work supports neuroprotective and cognitive effects with reasonable consistency.
No Western regulatory body has evaluated it, and no independent replication of the clinical findings has been published in English-language journals. Reports of cognitive enhancement in healthy people are anecdotal.
Dosing in the literature
Figures below are quoted from published studies, with the species or population they were measured in. They are records of what was studied, not recommendations.
| Studied in | Amount | Route | Source |
|---|---|---|---|
| Human — Russian clinical use, cognitive and stroke indications | 0.1% or 1% intranasal solution; daily amounts in the low-milligram range | intranasal | PubMed |
| Human — acute stroke protocols described in Russian literature | Higher doses over defined courses; see source | intranasal | PubMed |
Commonly reported ranges
These are amounts people report using. They are not from any study, have not been evaluated for safety, and are reproduced here only because they circulate widely and are better seen alongside the evidence than instead of it.
| Reported by | Amount | Route |
|---|---|---|
| Commonly reported | 300–600 µg daily, divided | intranasal |
Intranasal is the route with clinical data behind it, chosen for direct nose-to-brain delivery. Subcutaneous injection is a community practice with no supporting study, and there is no basis for assuming equivalence between routes.
Handling and storage
The Russian product is a nasal solution. Research-market Semax is usually a lyophilised powder for reconstitution and use as nasal drops or spray.
Courses of one to two weeks rather than continuous indefinite use is the pattern in the clinical literature.
Side effects
Reported as well tolerated in Russian clinical use, with nasal irritation the most common complaint.
Because it lacks the steroidogenic portion of ACTH it does not carry the cortisol effects of the parent hormone.
Long-term and independent safety data outside Russia does not exist. Community reports occasionally mention irritability or headache.
Combinations
Commonly combined with Selank in community use, the two being from the same Russian programme and often described as complementary — Semax for cognition, Selank for anxiety. No study has evaluated the combination.
Research status
Developed at the Institute of Molecular Genetics in Moscow and registered in Russia in the 1990s. The published literature covers BDNF induction, neuroprotection, and clinical use in stroke.
The limiting factor is that essentially the entire clinical evidence base is Russian, largely untranslated, and unreplicated elsewhere.
Legal status
A registered medicine in Russia and some neighbouring countries. Not approved in the US, EU, UK, Canada, or Australia. Sold in Western markets for research use only.
WADA status
Not specifically named on the Prohibited List. Falls under WADA class S0, which prohibits any pharmacological substance not currently approved by any governmental regulatory health authority for human therapeutic use. Treat it as prohibited in sport.
Conclusion
Semax is a real registered medicine with a real clinical dossier — in one country, in one language, with no independent replication.
That places it well above the compounds here with no human data, and well below anything approved in a jurisdiction whose review process you can actually inspect. The intranasal route is the one with evidence; injecting it is improvisation.
Sources
Track your own Semax protocol
Peppers logs your doses, models your levels from this half-life, tracks your vials and tells you when you will run out. Free on iPhone.
Reference and educational information only. Not medical advice. Nothing here diagnoses, treats, or prescribes, and nothing here is a recommendation to use any compound. The compounds described are research chemicals and are not approved for human consumption. Legal and anti-doping status change — the review date above is when these claims were last checked. Talk to a qualified clinician about anything you intend to take.