Semax vs Selank

Two Russian nasal peptides from the same institute — what is each for, and does either have evidence that can be checked?

No head-to-head trial — cross-trial comparison
In one paragraphSemax and Selank come from the same Moscow institute and share the same stabilising tail; the difference is the front end. Semax is built on a fragment of the stress hormone ACTH and is registered in Russia for stroke and cognitive indications. Selank is built on the immune peptide tuftsin and is registered there as an anxiolytic. Both are nasal drops, both have years of Russian clinical use, and both sit at grade D on this site for the same reason: the human literature is almost entirely Russian-language, largely uncontrolled or poorly reported by international standards, and has not been replicated by independent groups. Neither is approved in the EU, US or UK.

Side by side

D SemaxD Selank
LYO grade (best outcome)DD
Built fromACTH(4-7) + Pro-Gly-ProTuftsin (Thr-Lys-Pro-Arg) + Pro-Gly-Pro
Length7 amino acids7 amino acids
Registered in Russia forIschaemic stroke; cognitive indicationsAnxiety disorders
FormNasal dropsNasal drops
Human trials to international standardNone identifiedNone identified
Independent replicationNone foundNone found
Approved in EU / US / UKNoNo
WADANot on the listNot on the list
Verdict

There is no evidence-based winner. If the question is which is for what, Semax is the cognition-and-stroke peptide and Selank the anxiety peptide, by Russian registration. If the question is which one works, neither has a trial that meets international standards, and the honest answer is the same for both: unproven.

Same tail, different head

Both peptides end in the same three amino acids, Pro-Gly-Pro, added to slow the enzymes that would otherwise break a short peptide down in minutes. What sits in front of that tail is the difference. Semax carries residues 4 to 7 of ACTH — the fragment that keeps the hormone's effects on the nervous system without its effect on the adrenal glands. Selank carries tuftsin, a four-amino-acid immune-signalling peptide. Both were developed at the Institute of Molecular Genetics in Moscow, which is also where most of the literature on them comes from.

What the Russian registrations rest on

Semax has been a registered medicine in Russia since the 1990s, for acute ischaemic stroke and for cognitive indications; Selank was registered later as an anxiolytic. The trials behind those registrations exist, and some of the Selank studies compared it against benzodiazepines. The problem is not that the work was never done; it is that it was done to a standard that cannot be checked from outside — often open-label, often without a proper comparison group, published largely in Russian outside the indexed international literature, and never replicated by a group that did not develop the compound.

Why both are grade D despite being approved somewhere

LYO grades the evidence, not the paperwork. A registration is a regulatory fact and is recorded on each compound's page under Russia; the grade reflects whether controlled human trials meeting international standards support the claim. The contrast with GHRP-2 is instructive: it is approved in Japan as a diagnostic, and its diagnostic outcome is graded A — because the data behind that approval are checkable. Semax and Selank's are not, so the grade stays where the checkable evidence is.

Safety and legality

Both are reported as well tolerated in Russian use, and both have been used clinically there for years, which is reassuring without being the same thing as pharmacovigilance data. Neither is approved in the EU, the US or the UK; in the EU and UK, supplying either for human use is an offence for the seller. Neither is on the WADA Prohibited List.

Questions people actually ask

Why is Semax grade D if Russia approved it?
Because the grade measures the evidence, not the approval. The Russian trials have not been published to a standard that lets them be checked, and no independent group has replicated them. Registration in one country is recorded on the page; it does not lift the grade.
Is Selank an alternative to benzodiazepines?
Small Russian studies compared it with benzodiazepines and reported similar anxiety reduction without sedation. They are small, come from the originating institutes, and have not been replicated. That is an interesting claim, not an established one.
Are Semax and Selank legal in the EU, US or UK?
Neither is an approved medicine in any of them. In the EU and UK, selling either for human use is an offence for the seller. Semax is among the substances the FDA's compounding review has considered in the US; neither is approved there.

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 identified.
  2. 2
    Searches of PubMed and trial registries for Selank human trials outside Russia.LYO literature search, September 2026No independently replicated randomised trials identified.
  3. 3
    State Register of Medicinal Products of the Russian Federation (ГРЛС).Russian Ministry of HealthSource for the Russian registrations.