Selank: research, side effects and dosage in studies

In short

Selank is a synthetic peptide of seven amino acids that has been studied for anxiety in only a few small Russian patient studies [1, 2, 3]B. It has no marketing authorisation in the EU [7]regulator.

• Selank has been studied in three Russian studies with 60 to 70 patients each: two compared it with a benzodiazepine and one added it to benzodiazepine treatment. The investigators report a similar anti-anxiety effect [1, 2]B.
• The studies are small and published in Russian, and this page is based on their English abstracts. These do not describe randomisation or blinding [1, 2, 3]B.
• A US review calls Selank a poorly studied Russian drug that is sold to US consumers as a dietary supplement [6].
• No figures for harms are given, and long-term safety has not been studied independently [3]B [6].
• In Finland Selank is in Annex 1 A of the medicines list, so it is treated like a prescription-only medicine [9]regulator, and Fimea warns against injectable peptides bought online [8]regulator.

What is Selank?

Selank is a synthetic peptide made of seven amino acids (Thr-Lys-Pro-Arg-Pro-Gly-Pro). According to the authors of a laboratory study, it has long-lasting anti-anxiety and memory-related effects [5]D.

A US review groups Selank with substances acting on the GABA system. The review calls it a poorly studied Russian drug that is sold to US consumers as a dietary supplement [6].

Selank has no marketing authorisation in the EU [7]regulator. A Belgian official laboratory found it in seized products, which are sold online as powder for injection or as nasal sprays [4]D. Basics: What are peptides?. All substances: Peptides A-Z.

Evidence at a glance

Each cell gives the kind of study and its source. The letter is the evidence level, not the result.

"-" = no such study is known.

What is Selank studied for?

Selank has been studied in humans for anxiety disorders, and no use is approved in the EU [1, 2, 3]B [7]regulator.

• Generalised anxiety disorder and neurasthenia: one study, compared with medazepam [1]B.
• Phobic, anxiety and somatoform disorders: one study, compared with phenazepam [2]B.
• Added to benzodiazepine treatment: one study in which Selank was added to phenazepam [3]B.

Online claims. Selank is often marketed online for memory and focus. The only human data on memory come from a study of anxiety patients that reports a mild memory-related effect without figures [2]B. We know of no study of memory in healthy people.

How does Selank work?

How Selank works is not known for certain. In a laboratory study Selank enhanced the binding of GABA to rat brain cell membranes, and the researchers proposed this as one mechanism of its anti-anxiety effect [5]D. GABA is the brain's main calming messenger, and benzodiazepines act on the same system [6].

In the same study Selank blocked the effect of diazepam and olanzapine on binding, and the researchers say the binding sites do not appear to be the same [5]D. In a patient study a blood marker related to the breakdown of enkephalins changed during Selank treatment, mostly in generalised anxiety disorder [1]B. Neither finding yet shows how the substance works in humans.

Has Selank been studied in humans?

Yes, but only a little. Anxiety has been studied in three small Russian patient studies, published in Russian. They do not describe randomisation or blinding and give no exact figures for group differences [1, 2, 3]B. In addition, one small brain imaging study was done in healthy volunteers [10]B.

Human studies

• Selank vs medazepam (2008). 62 patients with generalised anxiety disorder or neurasthenia. Thirty received Selank and 32 received medazepam, a benzodiazepine. The investigators report that the anti-anxiety effect was similar in both, and that Selank also had anti-fatigue and stimulating effects [1]B.
• Selank vs phenazepam (2014). 60 patients with phobic, anxiety or somatoform disorders. The investigators reported a clear anti-anxiety and a mild memory-related effect. The anti-anxiety effect lasted for a week after the last dose [2]B.
• Selank added to phenazepam (2015). 30 patients received phenazepam alone and 40 received phenazepam plus Selank. The investigators report that the combination worked sooner and that phenazepam side effects, such as sedation and memory problems, were milder [3]B.
• Healthy volunteers, brain imaging (2020). 52 healthy participants received an injection of Selank, Semax or placebo, and functional connectivity in the brain was measured with MRI before the injection and 5 and 20 minutes after it. Groups differed in the connections between the amygdala and the temporal lobe. The abstract reports no effects on anxiety, memory or harms [10]B.

All three studies come from the same Russian research setting and share authors [1, 2, 3]B. The patient studies had no placebo group. The only placebo-controlled Selank study we know of is the brain imaging study in healthy people [10]B.

Who studies Selank?

Almost all Selank research is Russian. N. F. Myasoedov is an author of all three patient studies and of the laboratory study [1, 2, 3]B [5]D, and the laboratory study was done at the Institute of Molecular Genetics of the Russian Academy of Sciences in Moscow [5]D. Outside Russia there is a US review [6] and a Belgian official laboratory's analysis of seized products [4]D.

Author of this page: the editorial team

This page was written by the Molecular Recovery editorial team. The draft was made with the help of AI, and the claims have been checked against the sources (AI policy). The page has not been medically reviewed. How we work: About us.

What are the side effects of Selank?

The side effects of Selank are not well known. No figures for Selank's harms are available from the studies, and there are no independent studies of its long-term safety [1, 2, 3]B [6].

What users report. In the Reddit accounts we compiled (not research), 23 of 62 people (37%) reported some harm, most often: anxiety or irritability (9, 15%), headache (4, 6%) and insomnia (3, 5%). People tend to post when something goes wrong, so this share does not tell how common harms are. The same substance both eased and worsened anxiety: 21 (34%) reported less anxiety, and 9 (15%) anxiety or irritability as a harm. 36 people (58%) used other substances at the same time, most often Semax (22). The harms in detail: Selank user experiences.

What the studies say

The 2014 study compared the tolerability of Selank and phenazepam, but no numbers for harms are given [2]B. In the 2015 study the investigators report that Selank seemed to reduce phenazepam side effects. That says nothing about Selank's own harms [3]B.

Risks in products

The US review points out that new substances acting on the GABA system should be evaluated carefully for abuse potential before they reach consumers [6].

According to Fimea, there is no reliable information on the content, quality and safety of products sold as peptides. In injectables, impurities such as endotoxins can cause serious health harm [8]regulator. More: Side effects and safety.

Interactions and who has no data

Interactions have hardly been studied. In humans Selank has been given together with phenazepam, and the investigators report that phenazepam side effects were milder [3]B. In the laboratory Selank blocked the effect of diazepam and olanzapine on GABA binding [5]D. What this means for a person taking these medicines is not known.

According to the review, some substances acting on the GABA system have caused breathing depression at high doses or together with other sedatives [6]. The review does not report this for Selank. There are no data for pregnancy or breastfeeding, children or older people.

What speaks against it and what is unknown

There is no direct counter-evidence, but the positive results come from small studies whose design is not described in detail [1, 2, 3]B.

Counter-evidence

• Researchers at a Belgian official laboratory wrote in 2020 that, to their knowledge, Selank and Semax had not completed any clinical trials [4]D.
• A US review calls Selank poorly studied [6].
• The studies had no placebo group; the comparison was another anti-anxiety drug [1, 2, 3]B. Without a placebo control the effect of the substance cannot be separated from the effect of expectations.

What the evidence does not support

• "Selank works as well as benzodiazepines": the investigators report a similar effect, but no figures for group differences are given [1, 2]B.
• "Selank improves memory in healthy people": we know of no study of memory in healthy people. The only study in healthy people measured brain connectivity [10]B, and the memory finding comes from anxiety patients [2]B.
• "Selank is safe": there are no figures for harms, and long-term safety has not been studied independently [3]B [6].
• "The vial always contains what the label says": according to Fimea, there is no reliable information on the content of peptide products [8]regulator.

Selank dosage in studies

Selank has no approved dosage in the EU, because it has no marketing authorisation [7]regulator. The patient studies were published in Russian, and their abstracts give neither doses nor the route of administration [1, 2, 3]B, so there is no dose table.

According to the Belgian laboratory, such peptides are sold online as powder for injection or as nasal sprays [4]D. That does not tell what the studies used and is not a recommendation.

Because the published summaries of the studies do not give their doses, there is no dose page, and no calculator page opens with Selank preselected. The general calculator's list includes Selank only to fill in a vial size. Doses for other substances: Dosing.

Selank vs Semax: what is the difference?

They are different substances, but they are often sold side by side. Both were found among seized products analysed by a Belgian official laboratory [4]D.

• Selank: a seven-amino-acid peptide studied for anxiety in small Russian studies [1, 2, 3]B [5]D.
• Semax: a different peptide, studied mainly in connection with stroke. More: Semax: research and side effects.
• In common: neither has a marketing authorisation in the EU, and to the laboratory researchers' knowledge neither had completed clinical trials [4]D [7]regulator.

Is Selank legal in Finland?

Selank is listed in Annex 1 A of Fimea's medicines list [9]regulator. Annex 1 A substances are controlled as medicines in Finland and are always treated like prescription-only medicines. Selank has no marketing authorisation [7]regulator.

• Medicines list. In the Finnish medicines list (230/2025) Selank is named in annex 1 A, which covers medicinal substance analogues and prohormones classified as medicines. The same annex also names N-acetyl-selank [9]regulator.
• Marketing authorisation. Selank does not appear in the EMA medicines data file generated on 15 Sep 2026 [7]regulator.
• Fimea warning, 29 June 2026. Fimea warned about injectable peptides bought online and sold as "for research use only". According to Fimea, that label means the product is not intended for humans [8]regulator.
• Imports. Ordering medicines from outside the EU is covered on Peptides and the law in Finland. Bringing them from travel: Travelling with peptides.

This is not legal advice. Disclaimer.

How is a Selank product assessed?

You cannot be sure of the content of a Selank product. According to Fimea, there is no reliable information on the content, quality and safety of products sold as peptides [8]regulator.

The Belgian laboratory had to develop its own method to identify such peptides in seized products [4]D. A seller's own certificate of analysis (COA) does not by itself prove the content or safety. For a certificate even to describe the content, it should identify the substance by mass spectrometry (MS), state the amount and purity, and cover the same batch as the vial. More: How to read a COA and check a test result. Handling: Mixing and handling.

FAQ

Read the research yourself: sources

Every source opens the original publication or the regulator's page. The level shows what the source itself reports.

1. Zozulia AA, et al. Efficacy and possible mechanisms of action of a new peptide anxiolytic selank in the therapy of generalized anxiety disorders and neurasthenia. Zh Nevrol Psikhiatr Im S S Korsakova. 2008;108:38-48. (In Russian.) PMID 18454096 B
2. Medvedev VE, et al. A comparison of the anxiolytic effect and tolerability of selank and phenazepam in the treatment of anxiety disorders. Zh Nevrol Psikhiatr Im S S Korsakova. 2014;114:17-22. (In Russian.) PMID 25176261 B
3. Medvedev VE, et al. Optimization of the treatment of anxiety disorders with selank. Zh Nevrol Psikhiatr Im S S Korsakova. 2015;115:33-40. (In Russian.) PMID 26356395 B
4. Vanhee C, et al. The occurrence of putative cognitive enhancing research peptides in seized pharmaceutical preparations: an incentive for controlling agencies to prepare for future encounters of the kind. Drug Test Anal. 2020;12:371-381. PMID 31667971 D
5. Vyunova TV, et al. Peptide-based anxiolytics: the molecular aspects of heptapeptide Selank biological activity. Protein Pept Lett. 2018;25:914-923. PMID 30255741 D
6. Doyno CR, White CM. Sedative-hypnotic agents that impact gamma-aminobutyric acid receptors: focus on flunitrazepam, gamma-hydroxybutyric acid, phenibut, and selank. J Clin Pharmacol. 2021;61 Suppl 2:S114-S128. PMID 34396551 (review)
7. European Medicines Agency. Medicine data (human medicines, data set of 15 Sep 2026): Selank not listed. EMA regulator
8. Fimea. Fimea varoittaa: älä käytä verkosta ostettuja pistettäviä peptidejä / Fimea warns: do not use injectable peptides purchased online. 29 Jun 2026. Fimea regulator
9. Finland. Lääkeluettelo (Fimea medicines list), 230/2025, annex 1 A. Finlex regulator
10. Panikratova YR, Lebedeva IS, Sokolov OY, et al. Functional Connectomic Approach to Studying Selank and Semax Effects. Dokl Biol Sci. 2020;490(1):9-11. PMID 32342318 B

Research sources checked 9-13 Oct 2026. Regulator and registry sources checked 15 Sep 2026.

Evidence levels: A = randomised human trial or meta-analysis · B = observational human study or case series · C = animal study · D = cell or laboratory study · E = not peer-reviewed · regulator = a regulator's assessment or decision, not research evidence. The marker official means official product information (summary of product characteristics or label); it is not research evidence. For a review, the level shows what kind of research the statement rests on. No level: statements that something has not been studied, reviews' interpretations, named hypotheses and the general rules in our certificate-of-analysis guide.

Content is general information about research, not medical advice. If you have symptoms, contact a healthcare professional.