Semax and Selank explained: Russia's nasal peptides

Semax and Selank are registered medicines in Russia and unapproved almost everywhere else. Here is what the research shows, and what is known about Adamax and Adalank.

Semax and Selank are two short peptides developed in Russia and usually given as nasal drops. They are often described online as "nootropics," a loose term for substances meant to support focus or mood. In Russia they are registered medicines. In the US, Europe and most other places they are not approved for any use.

This post explains what each one is, what the research actually shows, where they stand with regulators, and how the newer analogs Adamax and Adalank fit in.

A shared design trick

Both peptides are seven amino acids long and end in the same three: proline, glycine, proline (Pro-Gly-Pro). That tail was added to slow the breakdown of a short, natural peptide fragment so it lasts long enough to have an effect.

Semax starts with a fragment of ACTH, a pituitary hormone (the sequence is Met-Glu-His-Phe-Pro-Gly-Pro). The fragment chosen does not carry ACTH's hormone effects on the adrenal glands.
Selank is built on tuftsin, a small peptide involved in immune function (the sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro). It was developed at the Institute of Molecular Genetics of the Russian Academy of Sciences.

What Semax research shows

Most of the mechanism work on Semax comes from animal studies. A 2006 rat study found that a single dose raised levels of BDNF, a protein that supports nerve cell growth and survival, in the hippocampus by about 1.4-fold. Other animal work points to effects on dopamine and serotonin signaling and protection in models of reduced blood flow to the brain.

In Russia, Semax is used for stroke, transient ischemic attack, memory and cognitive problems, and optic nerve disease. It appears on the Russian government's List of Vital and Essential Drugs, approved in December 2011.

The human evidence behind those uses is mostly small Russian clinical studies. Many were not double-blind or placebo-controlled in the way Western regulators expect, and there is little independent randomized data from outside Russia. Online claims about sharper focus in healthy people rest mainly on user reports.

What Selank research shows

Selank is registered in Russia as an anti-anxiety medicine. Lab studies suggest it affects GABA signaling, slows the breakdown of enkephalins (natural pain- and mood-related peptides), and shifts levels of some immune signaling molecules.

The best-known human study, published in a Russian journal in 2008, compared Selank with medazepam, a benzodiazepine, in 62 people with generalized anxiety disorder or neurasthenia. Both reduced anxiety scores by similar amounts, and the authors reported less sedation with Selank and no withdrawal on stopping.

That is an interesting result, but the trial was small, had no placebo group, and was not blinded to modern standards. It has not been repeated in a large independent trial.

Approval status abroad

Russia: both are registered medicines, and both have been available in Russian and Ukrainian pharmacies.
United States: neither is FDA-approved. The FDA lists Semax and Selank among bulk substances that may pose significant safety risks in compounding, citing possible immune reactions and limited safety data.
Europe, UK, Australia: neither is authorised.

There has been one notable US development. In July 2026, the FDA's Pharmacy Compounding Advisory Committee voted 8 to 5, with one abstention, to recommend adding Semax to the list of substances compounding pharmacies may use with a prescription. The proposed uses discussed were cerebral ischemia, migraine and trigeminal neuralgia. That vote is advisory only. The FDA still has to make its own decision, and Selank was not part of that meeting.

For athletes, neither peptide is named on the 2026 WADA Prohibited List. Whether a substance approved only in Russia falls under WADA's catch-all rule for non-approved substances is not spelled out, so anyone subject to testing should check with their anti-doping body.

Adamax and Adalank

Adamax and Adalank are newer, modified versions sold as ready-made nasal sprays.

Adamax is described as a Semax analog with chemical caps added to the ends of the chain. Descriptions of its exact structure vary between sellers.
Adalank is described as Selank with an acetyl group on one end and an amide on the other.

The caps are meant to slow breakdown and make the peptide last longer. That is a reasonable idea in chemistry terms, but it has not been tested. We could not find any published study on either compound. Everything said about them is borrowed from Semax and Selank research and from user reports, and changing a molecule can change how it behaves in the body in ways nobody has measured.

What this adds up to

Semax and Selank have more history than most research peptides: decades of Russian clinical use, registered status there, and a body of animal research. The human trials, though, are small and mostly from one country, and the case for using them in healthy people to boost focus or calm is weak. Adamax and Adalank have no research of their own.

Each compound has its own page with evidence ratings, regulatory status and a spray-math explainer: Semax, Selank, Adamax and Adalank.

This is educational information, not medical advice.