Research library

Selank Research Overview: Tuftsin Analogue Pharmacology, Anxiolytic-Type Findings and Regional Trial Evidence

Compiled by:: Peptide Pilots Scientific Content Team
Reviewed by:: Peptide Pilots Quality & Compliance review
Last revised:: 3 September 2026

What does published research establish about Selank's mechanism and clinical evidence, and how geographically limited is that evidence?

Selank is a synthetic heptapeptide analogue of the endogenous immunomodulatory peptide tuftsin, extended with a C-terminal Pro-Gly-Pro sequence for enzymatic stability. It has been studied mainly for anxiolytic-type and immunomodulatory activity, without the sedative or dependence liabilities associated with benzodiazepines in the animal models used. It holds regulatory approval and a clinical-trial literature in Russia, primarily for generalised anxiety and mixed anxiety-depressive presentations, administered intranasally. As with related regional peptides, it is not approved by the FDA, EMA or other major Western regulators, and independent replication outside that literature is limited.

This page is an educational literature summary for laboratory professionals. It is not medical advice, not a description of product performance, and it does not describe or endorse human or veterinary use. Materials referenced are supplied for controlled laboratory research only.

What is Selank?

Selank is a linear heptapeptide (Thr-Lys-Pro-Arg-Pro-Gly-Pro) derived from the naturally occurring immunomodulatory tetrapeptide tuftsin, with an added Pro-Gly-Pro extension intended to slow proteolytic degradation.

In laboratory work it is used in rodent anxiety and stress-behaviour paradigms, immune-cell functional assays, monoamine and BDNF expression studies, and in registered clinical studies (mainly regional to Russia) using intranasal administration for anxiety-related indications.

Selank names and identifiers

Also referred to as: heptapeptide tuftsin analogue; Thr-Lys-Pro-Arg-Pro-Gly-Pro; Selank (Селанк)

Peptide sequence	Thr-Lys-Pro-Arg-Pro-Gly-Pro (tuftsin-Pro-Gly-Pro)
Molecular formula	C33H57N11O9
Molecular weight	≈751.9 g/mol
CAS number	129954-34-3
Parent sequence	Extension of tuftsin (Thr-Lys-Pro-Arg), an endogenous tetrapeptide fragment of IgG heavy chain
Regulatory status	Approved and marketed in Russia as an intranasal formulation; not approved by the FDA or EMA

Selank research background

Selank was developed at the Institute of Molecular Genetics of the Russian Academy of Sciences, following the same Pro-Gly-Pro-extension strategy used to stabilise the related peptide Semax, applied here to the immunomodulatory tetrapeptide tuftsin rather than an ACTH fragment.

Tuftsin itself was originally described as a phagocytosis-stimulating peptide fragment of immunoglobulin G, giving Selank research a dual immunological and behavioural-pharmacology lineage.

From the 1990s onward, Russian research groups reported anxiolytic-type effects in rodent models without motor-impairing or sedative effects typical of benzodiazepines, prompting clinical development for anxiety-spectrum indications; this literature remains largely regional and has not been extensively replicated internationally.

Proposed Selank mechanisms and pathways

Evidence is separated by study type. In-vitro and animal findings describe model systems and do not establish equivalent behaviour in humans.

Selank in-vitro and cell-based evidence

Selank retains some tuftsin-like activity on immune cell function in assays of phagocytic and cytokine responses, consistent with its structural derivation from tuftsin.
Reported biochemical work links Selank to modulation of enzymes that degrade endogenous regulatory peptides (including enkephalinase-type activity), proposed as one route by which it could influence central peptide tone.
Cell and tissue studies report effects on brain-derived neurotrophic factor and monoamine-related gene expression, paralleling findings reported for Semax.

Selank animal-model evidence

Rodent models of conditioned anxiety and elevated plus-maze behaviour report anxiolytic-type effects following Selank administration, without the sedation or motor impairment produced by benchmark benzodiazepines in the same studies.
Studies report effects on stress-induced changes in serotonergic and GABAergic markers, proposed as contributing mechanisms distinct from direct GABA-A receptor allosteric modulation.
Immunomodulatory studies in rodents report effects on cytokine profiles and antibody responses consistent with tuftsin-family activity.

Published Selank human-study evidence

Regional randomised and open-label studies, predominantly conducted in Russia, report reductions in anxiety rating-scale scores with intranasal Selank in generalised anxiety and mixed anxiety-depressive disorder populations.
Some studies report improvements in cognitive-performance measures under stress conditions alongside anxiolytic ratings.
Pharmacokinetic human data are limited; as with Semax, most published clinical evidence relies on rating-scale and behavioural endpoints rather than direct central pharmacokinetic measurement.

Published Selank studies

Selected published studies involving Selank
Study	Model / type	Research question	Main observation	Citation
Kozlovskaya et al., original characterisation	Rodent, tuftsin-analogue structure-activity and behavioural work	Can a stabilised tuftsin analogue produce anxiolytic-type behavioural effects without sedation?	Reported anxiolytic-type activity in rodent models without the sedative/motor effects of benzodiazepine comparators.	Bulletin of Experimental Biology and Medicine, 2002
Semenova et al., neurochemical mechanism study	Rat, brain tissue biochemical and behavioural assay	What neurochemical changes accompany Selank's anxiolytic-type effects?	Reported effects on serotonergic markers and peptide-degrading enzyme activity coinciding with behavioural change.	Neuroscience and Behavioral Physiology, 2010
Regional GAD clinical trial	Human, randomised trial in generalised anxiety disorder, Russia	Does intranasal Selank reduce anxiety symptom scores versus comparator/placebo?	Reported reduced anxiety rating-scale scores in the Selank-treated group in a regionally conducted trial.	Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova (regional journal), 2010
Tuftsin immunopharmacology background	Review of tuftsin receptor/immune-cell literature	What is the established immunological activity of the parent tuftsin sequence?	Documented tuftsin's stimulatory effects on phagocytosis and immune-cell function, forming the pharmacological basis for Selank's proposed dual activity.	Annals of the New York Academy of Sciences, 1983

Limitations of the Selank evidence

The majority of controlled clinical evidence for Selank originates from a single regional (Russian) literature and has not been independently replicated in internationally peer-reviewed multicentre trials.
Sample sizes in cited clinical studies are generally modest, and reporting of randomisation and blinding procedures varies relative to current international standards.
No single validated molecular target has been established; proposed mechanisms (enkephalinase-type modulation, monoaminergic effects, tuftsin-receptor immune activity) remain associative rather than causally confirmed.
Selank is not evaluated or approved by the FDA, EMA, MHRA or TGA, and no equivalent Western regulatory pharmacology/safety dossier is publicly available.
Cross-study comparability is limited by variable dosing regimens, administration schedules and outcome instruments across the regional literature.

Selank laboratory characteristics

Handling and analytical information reported in the literature and in supplier documentation. Values apply to laboratory materials and are not directions for any other use.

Appearance	White to off-white lyophilised powder
Solubility	Freely soluble in water
Lyophilised storage	Commonly stored at −20 °C, desiccated and protected from light
Reconstituted handling	Aqueous solutions are typically refrigerated and used within a limited window
Analytical testing	RP-HPLC purity and MS identity are standard characterisation methods reported in the primary literature
Stability considerations	Peptide bond hydrolysis and proline-adjacent cleavage are documented degradation concerns

Frequently asked Selank research questions

Is Selank related to benzodiazepines?

No. It is a peptide structurally derived from tuftsin and is pharmacologically distinct from benzodiazepines, which act as GABA-A receptor allosteric modulators.

Is Selank approved outside Russia?

No. It is marketed and clinically used in Russia but has not been approved by the FDA, EMA or other major Western regulatory agencies.

What is tuftsin and why does it matter for Selank?

Tuftsin is an endogenous immunomodulatory tetrapeptide fragment of immunoglobulin G. Selank extends the tuftsin sequence for stability, giving it a proposed dual behavioural and immune pharmacology rooted in tuftsin's known activity.

How strong is the human clinical evidence?

There are several regionally conducted randomised and open-label trials in anxiety-related populations, but this literature has not been extensively replicated by independent international research groups.

Selank primary references

Kozlovskaya MM, Kozlovsky II, Val'dman EA, et al. (2002). Selank: an anxiolytic peptide preparation, mechanisms of action and pharmacological effects. Bulletin of Experimental Biology and Medicine. https://doi.org/10.1023/A:1015616818103
Semenova TP, Kozlovskaya MM (2010). Neurochemical aspects of the action of the peptide anxiolytic Selank. Neuroscience and Behavioral Physiology. https://doi.org/10.1007/s11055-010-9269-3
Regional clinical literature (Russia) (2010). Selank in the treatment of generalized anxiety disorder. Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova (regional journal). https://pubmed.ncbi.nlm.nih.gov/?term=selank+anxiety+disorder
Najjar VA (1983). Tuftsin, a natural activator of phagocyte cells: an overview. Annals of the New York Academy of Sciences. https://doi.org/10.1111/j.1749-6632.1983.tb23283.x

Authorship and revision

Compiled from primary literature and public databases. Every factual statement on this page is traceable to a listed reference. Compiled by Peptide Pilots Scientific Content Team; documentation and compliance review by Peptide Pilots Quality & Compliance review. First published 27 August 2026; last revised 3 September 2026. Pages are revised when the cited literature changes materially.

Catalogue reference

Peptide Pilots supplies Selank as a laboratory reagent with per-lot RP-HPLC and mass-spectrometry documentation. Quantities, testing, packaging and fulfilment details are on the catalogue page.

View Selank catalogue entry