Selank

A synthetic tuftsin-derived heptapeptide developed in Russia and researched as a non-sedating anxiolytic nootropic, with laboratory data spanning enkephalin, BDNF, GABAergic and monoamine signalling.

What it is

Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro (TKPRPGP). It is a stabilised analogue of tuftsin, a naturally occurring immunomodulatory tetrapeptide (Thr-Lys-Pro-Arg) that is a fragment of the immunoglobulin G heavy chain. The parent tuftsin sequence is extended with a Pro-Gly-Pro tripeptide tail, which slows enzymatic degradation and prolongs the peptide's activity relative to tuftsin itself. Selank was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences, in the same neuropeptide research lineage that produced Semax.

In research it is classified as a nootropic and anxiolytic peptide. It is studied almost exclusively as an intranasal preparation in animal and human work, since the peptide is water soluble and reaches the central nervous system without oral dosing. Supplied strictly for laboratory research use only, not for human or veterinary use.

How it works

Selank does not act on a single classical receptor. The most consistently reported mechanism is modulation of the endogenous enkephalin system: Selank inhibits enkephalin-degrading enzymes, prolonging the half-life of leu-enkephalin in serum. In the clinical anxiety work of Zozulya and colleagues, patients with generalised anxiety disorder showed shortened enkephalin half-lives that correlated with symptom severity, and Selank treatment lengthened that half-life alongside anxiety reduction. This enkephalinase-inhibiting action is thought to underpin much of the anxiolytic and regulatory profile.

Downstream, Selank influences several neurochemical systems studied in rodents. It rapidly elevates expression of brain-derived neurotrophic factor (BDNF) in the hippocampus, a neurotrophin central to neuroplasticity and stress resilience. It alters expression of genes governing GABAergic neurotransmission, including GABA-A receptor subunits, an effect it shares in part with GABA itself. Cerebral microdialysis work reports that Selank raises extracellular noradrenaline and dopamine in the prefrontal cortex with little effect on serotonin, a monoamine signature closer to a noradrenaline-dopamine modulator than to an SSRI. Together these actions are used to explain the research observation of an anxiolytic effect without the sedation typical of benzodiazepines.

What the research shows

The strongest human data come from a Russian randomised comparison against a benzodiazepine, while the mechanistic story rests on controlled rodent studies of BDNF, GABAergic genes and monoamines. The figures below are drawn directly from those published reports; every number is linked to its source.

Side Effects

Most of what is known about Selank's tolerability comes from Russian clinical studies, since the peptide is approved only in Russia (and reportedly Ukraine) for generalized anxiety disorder and neurasthenia and remains a research chemical elsewhere. In those trials it was generally described as well tolerated, with efficacy comparable to low-dose benzodiazepines but without the sedation, muscle relaxation, tolerance, or withdrawal typical of that drug class. Independent Western safety data are limited, long-term human studies are scarce, and it is not approved by the FDA or EMA. The points below reflect effects reported in the literature, not proof of safety.

Taken together, the available literature suggests Selank is usually well tolerated over short courses, with mild local irritation being the most consistently mentioned complaint and no clear signal of the dependence or sedation associated with benzodiazepines. That picture rests almost entirely on Russian clinical use and a small evidence base, so it should be read as encouraging rather than as established proof of long-term safety.

At a glance

Molecular formula C33H57N11O9, sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, confirmed via PubChem CID 11765600.

Dosing

Selank has no FDA or EMA approval, so all dosing figures come from Russian clinical use and published research, where it is given intranasally as a registered 0.15% solution for generalized anxiety disorder and neurasthenia. Human trials typically dosed it intranasally in divided doses over 14 days, comparing it against benzodiazepines rather than reporting a single standardized microgram target. Reported abstracts often omit exact microgram totals, and the more precise dose figures below come from animal studies. Treat everything here as documented study and clinical-use information for laboratory research context, not as instructions.

Independent, Western dosing data are limited: most human figures trace to a small number of Russian trials whose abstracts report route and duration more consistently than exact microgram totals, while the precise per-kilogram doses come from rodent work. This material is provided for laboratory research use only.

Preparing it

Selank is supplied as a lyophilised powder and is reconstituted with bacteriostatic or sterile water before use in the laboratory. For the general method and safe handling of the vial, see the reconstitution guide. To convert a target amount into a measured volume once the vial is mixed, use the concentration and dosing guide. Store the sealed vial cold and protect the reconstituted solution at 2-8 C.

Where to go next

Last updated on July 3, 2026