SelankWhat the studies show
A seven-amino-acid peptide built on the immune fragment tuftsin, registered in Russia as a nasal anxiety medicine on the strength of small open-label trials.
5 min read · Small human studies · Updated November 2026
In short
- Name
- selank (sold by Progression Labs as Selank)
- Evidence
- Small human studies
- Bottom line
- Small open-label Russian trials against benzodiazepines, with no placebo arm, plus single rat and test-tube studies on mechanism; registered as a medicine in Russia and untested in a blinded trial anywhere.
Before you read this
This guide explains what published studies found. That is all it is.
It is not medical advice and it is not instructions for using anything. Where a dose appears, we are reporting what a named study gave the people or animals in it — a fact about the study, not an instruction to you.
The compounds here are not approved by the FDA for use in people and are sold for laboratory research only. A study tells you what happened to the subjects in it; it does not tell you what would happen to you. Talk to a doctor first.
What it is
Selank is a chain of seven amino acids (Thr-Lys-Pro-Arg-Pro-Gly-Pro). The first four are tuftsin, a natural fragment of the antibody protein IgG that is known for its effects on immune cells; the Pro-Gly-Pro tail was added by chemists at the Institute of Molecular Genetics in Moscow to slow the peptide's breakdown in the body 1. It was developed there as an anti-anxiety compound and is given as drops or a spray into the nose. Selank is registered in Russia as a prescription medicine under that name, for generalised anxiety disorder and neurasthenia, a diagnosis used in Russia for chronic fatigue with irritability 1. It is not approved by the U.S. FDA or in the European Union, and it has not been tested in a clinical trial outside Russia.
The studies below call this molecule selank. Progression Labs sells it as Selank; the guide uses the store's name and the papers use theirs.
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The Russian anxiety trials
The main clinical paper is by Zozulya and colleagues, published in 2008 in the Korsakov Journal of Neurology and Psychiatry. It was an open comparison, meaning patients and doctors knew what was being given, in people with generalised anxiety disorder or neurasthenia: selank nasal drops on one side, the benzodiazepine medazepam on the other, over a short course 2. Anxiety ratings fell in both groups by a similar amount, and the selank group also showed less fatigue and weakness, which the authors called an anti-asthenic effect. The same paper reported that patients' blood levels of enkephalins, small natural opioid peptides, rose during treatment, and proposed that selank works partly by blocking the enzymes that break those peptides down 2.
A 2014 study from a Moscow psychiatry group compared selank with another benzodiazepine, phenazepam, in people with anxiety disorders and again reported comparable falls in anxiety scores 3.
What these trials have in common: they were open-label, small, run in Russia by groups connected to the peptide's developers, and none had a placebo arm. That is a weaker kind of evidence than a blinded placebo-controlled trial, because expectation alone moves anxiety scores, and a comparison against a drug that works tells you only that the two arms ended up in a similar place.
What it does in rats
Animal work has tried to explain the effect. A 2008 study gave rats selank into the nose and measured BDNF, a growth factor that supports neurons, in the hippocampus; BDNF expression rose within hours of the dose 4. A 2016 study in Frontiers in Pharmacology looked at gene activity in the brains of rats given selank and found changes in several genes involved in GABA signalling, the brain's main inhibitory system and the one benzodiazepines act on, which would fit the overlap seen in the clinical comparisons 5. The 2001 laboratory paper that first proposed the enkephalin mechanism showed selank slowing the breakdown of enkephalins by blood enzymes in a test tube 6.
Each of these is a single study from laboratories tied to the compound's development. None has been repeated by an independent group, and none shows a chain from the mechanism to a change in a person.
What is not known
There is no blinded, placebo-controlled trial of selank in any journal, in Russia or elsewhere, and no published safety data beyond the short Russian courses. Whether a peptide sprayed into the nose reaches the brain in amounts that matter is an open question for every nasal peptide, and selank's developers have proposed mechanisms, enkephalin breakdown, GABA genes, BDNF, rather than demonstrated one in people. The registration in Russia tells you that a national regulator accepted the open-label evidence; it does not tell you what the peptide does against placebo, because that comparison has never been published.
What these studies are, and aren't
Small human studies. Small open-label Russian trials against benzodiazepines, with no placebo arm, plus single rat and test-tube studies on mechanism; registered as a medicine in Russia and untested in a blinded trial anywhere.
Sources
- 1Vyunova TV, Andreeva L, Shevchenko K, Myasoedov N. Peptide-based anxiolytics: the molecular aspects of heptapeptide Selank biological activity. Protein & Peptide Letters, 2018 (review).
- 2Zozulya AA, Neznamov GG, Syunyakov TS, et al. Efficacy and possible mechanisms of action of a new peptide anxiolytic selank in the treatment of generalized anxiety disorders and neurasthenia. Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova, 2008.
- 3Medvedev VE, Tereshchenko ON, Israelyan AY, et al. A comparison of the anxiolytic effect and tolerability of selank and phenazepam in the treatment of anxiety disorders. Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova, 2014.
- 4Inozemtseva LS, Karpenko EA, Dolotov OV, et al. Intranasal administration of the peptide Selank regulates BDNF expression in the rat hippocampus in vivo. Doklady Biological Sciences, 2008.
- 5Volkova A, Shadrina M, Kolomin T, et al. Selank administration affects the expression of some genes involved in GABAergic neurotransmission. Frontiers in Pharmacology, 2016.
- 6Zozulya AA, Kost NV, Sokolov OY, et al. The inhibitory effect of Selank on enkephalin-degrading enzymes as a possible mechanism of its anxiolytic activity. Bulletin of Experimental Biology and Medicine, 2001.
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