Selank: Tuftsin Analogue — Peptide Anxiolytic Without Sedation

Selank (TP-7) is a synthetic heptapeptide with sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, developed at the Institute of Molecular Genetics and the Zakusov Institute of Pharmacology (Russia). Its structure preserves the complete sequence of endogenous tuftsin (Thr-Lys-Pro-Arg) — a tetrapeptide derived from IgG with well-described immunomodulatory action — and adds the Pro-Gly-Pro tripeptide to the C-terminus. This addition confers enzymatic resistance, extending effective CNS half-life and allowing prolonged action via BDNF and monoamine cascades, as described in scientific literature. Educational content — not medical prescription.

Vyunova et al. (2018, PMID 30255741) demonstrated that Selank acts as a positive allosteric modulator of the GABA-A receptor in a concentration-dependent, subtype-selective manner, without competing for the benzodiazepine (BZD) site. Skrebitsky et al. (2011, PMID 22390072) confirmed via patch-clamp in hippocampal CA1 neurons that Selank increases spike-dependent IPSC frequency — activating inhibitory interneurons — without altering spike-independent IPSCs. This molecularly distinct mechanism from benzodiazepines would explain, according to the authors, the absence of sedation, tolerance and dependence potential observed in studied models. Educational content based on scientific literature.

Kolik et al. (2019, PMID 31625062) demonstrated in an ethanol-induced cognitive dysfunction model that Selank normalized altered BDNF (Brain-Derived Neurotrophic Factor) levels in hippocampus and prefrontal cortex, simultaneously reversing object recognition memory impairment. BDNF is critical for synaptic plasticity and memory consolidation. BDNF modulation by Selank appears to be a primary effect — also observed in sleep deprivation and chronic stress models — connecting the peptide's anxiolytic and cognitive properties in a single molecular mechanism. Educational content based on scientific literature.

Most published studies on Selank are preclinical (animal models), predominantly from Russian research groups. The most relevant studies include: PMID 31625062 (Kolik et al., 2019 — neuroprotection and BDNF), PMID 36322304 (Konstantinopolsky et al., 2022 — morphine withdrawal), PMID 18661785 (Sarkisova et al., 2008 — antidepressant effect), PMID 16963804 (Czabak-Garbacz et al., 2006 — anxiety in Wistar rats) and PMID 32342318 (Panikratova et al., 2020 — first fMRI study in 52 healthy humans). Human evidence remains limited in scale, and large-scale RCTs according to FDA/EMA standards have not been published. Educational content — not medical prescription.

Yes — in Russia. Selank completed phase III clinical trials for generalized anxiety disorder (GAD) and obtained approval from the Russian Ministry of Health as an intranasal anxiolytic. This is the only formal regulatory approval for the peptide, restricted to the Russian context. Outside Russia — including Brazil (ANVISA), the United States (FDA) and the European Union (EMA) — Selank has no established regulatory approval. Educational content based on scientific literature.

Panikratova et al. (2020, PMID 32342318) conducted the first functional neuroimaging study of Selank in humans: 52 healthy participants underwent resting-state fMRI before, 5 min and 20 min after administration of Selank, Semax or placebo. Selank specifically modulated resting-state functional connectivity between the right amygdala and right temporal cortex — regions involved in emotional processing and fear regulation. This is the only published study with objective neuroimaging data in humans; the scale (N=52) is modest for definitive clinical conclusions, but represents a significant methodological advance. Educational content.

In studied models and Russian phase III clinical trials, Selank did not demonstrate sedation or cognitive impairment — on the contrary, studies reported nootropic effects (cognitive improvement) in animals with baseline deficit (Kolik et al., 2019, PMID 31625062). This profile pharmacologically differentiates Selank from classic benzodiazepines, which cause dose-dependent sedation. The proposed mechanism (allosteric modulation of GABA-A via distinct BZD site) would explain this absence of sedation. However, long-term human studies are scarce. Educational content — not medical prescription.

In phase III clinical trials conducted in Russia for GAD, and in published preclinical studies, no dependence potential or withdrawal syndrome associated with Selank were documented. The proposed mechanism — allosteric modulation of GABA-A via distinct benzodiazepine site — would avoid the classic molecular mechanisms of BZD dependence. However, the absence of evidence of dependence in short-duration trials is not equivalent to confirmed long-term safety, especially in the absence of large-scale controlled trials outside Russia. Educational content — not medical prescription.

Published preclinical studies reported no significant changes in body weight, hematological or biochemical parameters in Selank-treated animals (Czabak-Garbacz et al., 2006, PMID 16963804). In Russian phase III clinical trials for GAD, tolerability was described as good, without documented sedation or dependence. The neuroimaging study in 52 humans (Panikratova et al., 2020, PMID 32342318) reported no relevant adverse events. However, the human safety database is limited in scale and duration. Local nasal irritation is theoretically possible with intranasal formulation. Educational content.

As described in Russian literature, the predominant route of administration in approved clinical trials is intranasal, using a solution formulation approved by the Russian Ministry of Health. Preclinical studies also evaluated the intraperitoneal (IP) route in animal models. Vasil'eva et al. (2016, PMID 29787664) demonstrated that the route of administration influences which molecular mechanisms predominate. Details of dose ranges, frequency and duration of protocols described in the literature are available in the premium section of this platform. Individualization requires evaluation by a qualified healthcare professional.

Selank and Semax are heptapeptides developed in the same Russian ecosystem (Institute of Molecular Genetics + Zakusov Institute), both with heptapeptide structure containing stabilizing Pro-Gly-Pro. The pharmacological differences are marked: Semax is an ACTH(4-7)PGP analogue with primary cognitive/neuroprotective action via transcriptome and CREB/BDNF modulation; Selank is a tuftsin analogue with primary anxiolytic action via GABA-A (non-BZD site) and BDNF. The neuroimaging study (PMID 32342318) directly compared the two: Selank modulated amygdala-temporal connectivity (anxiety), Semax modulated distinct cognitive pathways. The combinatorial rationale in the literature points to complementary effects without target overlap. Educational content.

No. Selank has regulatory approval only in Russia (Russian Ministry of Health) for generalized anxiety disorder via intranasal formulation. In Brazil (ANVISA), the United States (FDA) and the European Union (EMA), Selank has no approval as a medication. Most available evidence comes from Russian studies, predominantly preclinical data. Randomized clinical trials according to Western regulatory standards (FDA/EMA) have not been conducted or published as of this page's review date. Educational content — not a guidance for use.