Semax

DNot approved (outside Russia)Nootropic and sleep peptides →ACTH(4-7)-Pro-Gly-Proheptapeptide nootropic
In one paragraphSemax is a seven-amino-acid peptide derived from ACTH, developed in Russia in the 1980s and registered there for stroke and cognitive indications. It is not approved in the EU, US or UK. The human literature is almost entirely Russian-language, largely uncontrolled or poorly reported by international standards, and has not been replicated by independent groups — which is why the cognitive and stroke claims sit at grade D despite the registration.
Schematic 3D structure of Semax
7 residues · ACTH(4-7) fragment with Pro-Gly-Pro tail · schematic
Overall gradeD No human evidence
Human trialsRussian-language, largely uncontrolled
Outcomes graded4
Last reviewed2 September 2026
EvidenceWhat it isHow it worksUnknownsMolecule & PKRegulationQuestionsReferences

What the human research shows

Registered somewhere is not the same as evidenced. Semax has decades of Russian clinical use behind it, and a literature that international reviewers have repeatedly found too thin and too opaque to grade. That is a statement about the available evidence, not a verdict on the molecule.

MetabolicCardioMuscleHealingNeuroImmuneSexualSkinAgeing

Evidence profile0–5

  • Metabolic & weight—0.0
  • Cardiovascular—0.0
  • Muscle & growth—0.0
  • Healing & repair—0.0
  • Neuro & sleepD0.0
  • Immune & inflammation—0.0
  • Sexual & hormonal—0.0
  • Skin & appearance—0.0
  • Ageing & longevity—0.0
No benefit outcome for Semax has both human evidence and a measurable effect, so the profile is empty. That is the finding, not a gap in the chart.
OutcomeGradeEffect sizeHuman studiesWhere the evidence comes from
Cognitive performanceDNo human evidenceNot measurableRussian-language, mostly uncontrolledSmall studies, often without blinding or a comparison group, published outside the indexed international literature. No independent replication.1
Stroke recoveryDNo human evidenceNot measurableRussian trials, not independently replicatedThe basis of the Russian registration. Not reproduced in trials meeting international reporting standards.1
Anxiety / stressDNo human evidenceNot measurableNone controlled internationallyClaims derive from animal work and from the related peptide Selank.
Safety in humansadverseDNo human evidenceNot measurableNo systematic international dataLong Russian clinical use is reassuring but not equivalent to pharmacovigilance data.
AMultiple good human trials, consistentBSome human trials, mostly consistentCFew or weak human studiesDAnimal or anecdotal onlyeffect size · red = adverse

Literature searched to 2 September 2026. Human studies only; animal and cell work informs the mechanism section and nothing else.

What it is

Semax is a fragment of adrenocorticotropic hormone with a three-amino-acid tail added to slow its breakdown. It was developed at the Institute of Molecular Genetics in Moscow and is given as a nasal spray. Russia registers it for stroke, optic-nerve conditions and cognitive complaints.

Almost nothing about it has been tested outside Russia. That is the central fact for anyone reading claims: the absence of Western trials is not evidence that it fails, and the presence of Russian registration is not evidence that it works.

How it is thought to work

It is reported to raise BDNF and NGF — growth factors involved in neuron survival and plasticity — and to modulate dopamine and serotonin systems. The mechanistic work is largely from the originating institutes and in animals.

What is still unknown

  • Essentially everything, by international evidence standards: effect size, durability, dose, long-term safety.
  • Whether the reported BDNF effects occur in humans at the doses used.

The molecule and how long it lasts

Identity
Formula
C37H51N9O10S
Molecular weight
813.9 g/mol
CAS number
80714-61-0
PubChem
CID 9811102

PubChem record, read 23 September 2026.

Pharmacokinetics
Route
Intranasal
Half-life
No human pharmacokinetic data; rat intranasal kinetics only

Animal data only — no human pharmacokinetic study: Kinetics of Semax penetration into the brain and blood of rats after intranasal administration (Russian)

Regulatory status

European Union
Unauthorised in the EU

Authorised in Russia only. Supplying it for human use in the EU is an offence under national medicines law.

United States
Not approved; compounding under review

Removed from FDA's Category 2 list on 22 April 2026; the Pharmacy Compounding Advisory Committee recommended it for the 503A bulks list in July 2026 (recommended 24 July 2026). Not on the list yet and not an approved drug. Sold otherwise as an unapproved 'research chemical'.

United Kingdom
Unlicensed medicine

No MHRA licence; supply for human use is an offence.

Australia
Schedule 4, unapproved

Prescription-only substance not on the ARTG. Possession without a prescription is an offence; imports without a prescription are seized.

Canada
Not authorised

No Drug Identification Number; selling it is illegal. Residents cannot import prescription drugs by mail.

Sport (WADA)
Not on the list

Approved in Russia, so S0 does not apply, and it is not named.

Questions people actually ask

Semax is approved in Russia — doesn't that count?
It counts as a regulatory fact, not as evidence of effect at the standard LYO grades on. The trials behind the registration are largely unavailable in the indexed international literature and have not been independently replicated.
Does Semax improve memory or focus?
No trial meeting international standards has tested it. The claims come from small Russian studies and from animal work.

One page per claimed effect

References

  1. 1
    Searches of PubMed and trial registries for Semax human trials outside Russia.LYO literature search, September 2026No randomised trials meeting international reporting standards were identified.

Change log

  • 2026-09-02Initial publication. Graded D on absence of internationally reported controlled evidence; Russian registration noted separately.