# Selank: Real Clinical Trials, One Country, No Replication By Nora Bissett, Pricing Editor (https://glpwatchdog.org/authors/nora-bissett) | Published: 2026-08-21 | Updated: 2026-10-30 Canonical page: https://glpwatchdog.org/research/selank-what-the-russian-trials-show > Selank was tested against a benzodiazepine in 62 patients with generalized anxiety disorder and reported similar anxiolytic effects. The study is from 2008, published in Russian, and has never been independently replicated. ## Key points - 62 patients with generalized anxiety disorder or neurasthenia: 30 on selank, 32 on medazepam, a benzodiazepine. - Anxiolytic effects were reported as similar, with selank also showing antiasthenic and psychostimulant effects. - An active comparator is a harder test than placebo, but the study is single-source and unreplicated outside Russia. - Selank is not approved in the US and is sold as a research chemical, outside prescription manufacturing standards. Selank is sold online as an anxiolytic peptide, and unlike most compounds in that market it has been tested in patients with a diagnosis. A comparative study of 62 people with generalized anxiety disorder and neurasthenia set selank against medazepam, a benzodiazepine, using standard psychometric scales. The anxiolytic effects of the two were reported as similar, with selank also showing antiasthenic and psychostimulant effects.[1] The trial is from 2008, it is published in Russian, and it has not been independently replicated in the English-language literature. ## What the study reported Sixty-two patients were studied: 30 received selank and 32 received medazepam. State was assessed with the Hamilton and Zung scales and the Clinical Global Impression. Alongside the clinical measures the researchers took a biological one, measuring enkephalin activity in blood serum.[1] - Anxiolytic effect: reported as similar between selank and the benzodiazepine comparator. - Selank additionally showed antiasthenic and psychostimulant effects, which the benzodiazepine did not. - Patients with these diagnoses had a decreased level of a leu-enkephalin parameter, correlated with disease duration and symptom severity. - That parameter rose during selank treatment, most clearly in the generalized anxiety group. The study’s strongest design feature is its active comparator. Testing a new compound against a drug already known to work is a harder test than testing it against placebo. > **We read this study in abstract, in translation. The full text is in Russian and we did not read it.** That means we cannot check the randomization, the blinding, the handling of dropouts or the pre-specification of endpoints, which are the things that decide whether a result means what it says. ## What is missing, and why it matters more than what is there The evidence base for selank sits almost entirely in one national literature, produced largely around the institute that developed the compound. That implies nothing improper; it is the ordinary situation for a drug that never went through a Western regulatory program. But independent replication is the mechanism by which a promising early result becomes a reliable one, and for selank that step has not happened. [Epitalon](https://glpwatchdog.org/research/epitalon-what-the-evidence-shows), from a different St. Petersburg institute, shows the same pattern. “Published in Russian” is not a reason to discard a study. Plenty of good science is published outside English. The problem is narrower and harder: *one* source of evidence, in *one* place, without outside replication, is a weak foundation regardless of which country it comes from, the United States included. > Selank’s evidence comes almost entirely from one national literature, largely from its developers’ institute, and no independent replication has been published. ## What that means if you are considering it - Selank is not an approved medicine in the United States, and what is sold here is a research chemical, outside the manufacturing and labeling standards that apply to prescription drugs. - Selank is not one of the six peptides in the interim compounding policy HHS announced on October 28, 2026, which does cover semax, and FDA lists selank acetate among substances whose nominations were withdrawn from its safety-risk Category 2.[2][3] - What you buy under that name has no guarantee of identity, purity or dose. That is a separate problem from whether the molecule works. - The clinical evidence is real but thin, single-source and unreplicated. - Generalized anxiety disorder has treatments with large, replicated, independent evidence bases. Substituting an unapproved peptide for them is a decision worth discussing with a clinician rather than a forum. For the regulatory position on research-use peptides generally, see [what FDA actually said about BPC-157](https://glpwatchdog.org/research/bpc-157-what-fda-actually-said). For how selank differs from semax under the October 2026 HHS policy, see [Semax vs Selank](https://glpwatchdog.org/research/semax-vs-selank). Selank's compounding status, evidence grade and the sellers we track are on our [selank profile](https://glpwatchdog.org/peptides/selank), and the other profiles are listed at [/peptides](https://glpwatchdog.org/peptides). ## Frequently asked questions ### Does selank work for anxiety? A 2008 comparative study of 62 patients with generalized anxiety disorder and neurasthenia reported anxiolytic effects similar to medazepam, a benzodiazepine, plus antiasthenic and psychostimulant effects the comparator did not show. It is published in Russian and has not been independently replicated in the English-language literature. ### Is selank approved? Not in the United States, where it is sold only as a research chemical, which places it outside the manufacturing, purity and labeling standards that apply to prescription medicines. Nor is it one of the six covered by the HHS policy of October 28, 2026, under which HHS does not intend to take enforcement action against 503A compounding; that policy covers semax but not selank. ### Is Russian research reliable? The language is not the issue. Plenty of sound science is published outside English. The weakness here is that the evidence comes from a single national literature, largely around the institute that developed the compound, with no independent replication. That would be an equally weak foundation anywhere. ### How was this article sourced? From the study abstract in translation. The full text is in Russian and we did not read it, which means we cannot verify the randomization, blinding or endpoint handling. We would rather say that than imply a closer reading than we did. ## References 1. Zozulia AA, Neznamov GG, Siuniakov TS, et al. [Efficacy and possible mechanisms of action of a new peptide anxiolytic selank in the therapy of generalized anxiety disorders and neurasthenia]. Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova. 2008. PMID: 18454096. https://pubmed.ncbi.nlm.nih.gov/18454096/ 2. U.S. Department of Health and Human Services HHS Enforcement Discretion Policy Regarding 503A Compounding Using Certain Peptide Bulk Drug Substances (with Appendices A and B), announced October 28, 2026. HHS. 2026. https://www.hhs.gov/sites/default/files/hhs-503a-peptide-enforcement-discretion-policy-appendix-b.pdf 3. U.S. Food and Drug Administration Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks. FDA. 2026. https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks --- Cite as: GLP Watchdog, Nora Bissett, "Selank: Real Clinical Trials, One Country, No Replication", published 2026-08-21, updated 2026-10-30. https://glpwatchdog.org/research/selank-what-the-russian-trials-show Canonical HTML page: https://glpwatchdog.org/research/selank-what-the-russian-trials-show Medical disclaimer: Nothing here is medical advice. We report on this subject; we do not treat anyone. Whether to begin a medication, supplement, or treatment, whether to adjust it, and whether to stop are questions for a clinician licensed to answer them, who knows your history.