Selank

Selank | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Synthetic Tuftsin Analogue | Research Peptide

Sequence: Thr-Lys-Pro-Arg-Pro-Gly-Pro (TKPRPGP) Classification: Heptapeptide — synthetic analogue of the endogenous immunopeptide tuftsin Molecular Formula: C₃₃H₅₇N₁₁O₉ Molecular Weight: 751.88 g/mol Purity: >99% (HPLC verified) Form: Lyophilised powder Available Sizes: 5mg | 10mg Storage: –20°C, away from light and moisture CAS Number: 129954-34-3

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What Is Selank?

Selank is a synthetic heptapeptide consisting of seven amino acids (Thr-Lys-Pro-Arg-Pro-Gly-Pro), developed by the Institute of Molecular Genetics of the Russian Academy of Sciences in collaboration with the V.V. Zakusov Research Institute of Pharmacology. It was designed as a metabolically stabilised synthetic analogue of tuftsin — a naturally occurring tetrapeptide (Thr-Lys-Pro-Arg) found within the Fc region of human immunoglobulin G heavy chains, where it plays an endogenous immunoregulatory role.

To address tuftsin's extremely short biological half-life in vivo, researchers extended the C-terminus of the native sequence with three additional natural L-amino acids — Pro-Gly-Pro — producing a compound with significantly enhanced metabolic stability while retaining and expanding the biological activity of the parent molecule. The result is Selank: a peptide with a unique pharmacological profile spanning neuropsychiatric, nootropic, and immunomodulatory research domains, and one of the most extensively studied research peptides to emerge from the Russian neuropharmacology literature.

Selank has been investigated in both preclinical animal models and clinical studies — including a registered clinical trial in generalised anxiety disorder (GAD) and neurasthenia — making it unusual among research peptides in having a degree of human clinical data behind it. It is approved and used as a pharmaceutical nasal spray in Russia and several other post-Soviet states, though it has not been evaluated by the FDA or EMA and remains an investigational compound in Western research contexts.

Our Selank is synthesised under rigorous quality-controlled manufacturing conditions, verified to a purity of greater than 99% by High-Performance Liquid Chromatography (HPLC) and Mass Spectrometry (MS), and supplied as a lyophilised (freeze-dried) powder for maximum stability.

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Research Background & Scientific Interest

Selank has accumulated an extensive and diverse body of preclinical and clinical research since its development, spanning anxiolytic pharmacology, cognitive neuroscience, neuroimmunology, enkephalin metabolism, and antiviral biology. Its multi-system mechanism of action — operating simultaneously across GABAergic, monoaminergic, and neurotrophic signalling pathways — distinguishes it from single-target anxiolytic compounds and has sustained continued scientific interest across several decades of research.

GABAergic Modulation & Anxiolytic Activity The most extensively characterised mechanism of Selank's anxiolytic activity involves the GABAergic system. Radioligand binding studies have demonstrated that Selank acts as a positive allosteric modulator of GABA-A receptors — increasing the binding of [³H]GABA and modulating chloride ion channel opening frequency in a manner functionally analogous to benzodiazepines, but through a distinct and non-overlapping binding site. This GABAergic action produces anxiolytic effects comparable in magnitude to classical benzodiazepine drugs in both preclinical models and clinical studies, without the sedation, muscle relaxation, amnesia, tolerance, or dependence potential associated with that drug class. Gene expression studies have further shown that Selank modulates the expression of key genes involved in GABAergic neurotransmission — including Drd1a, Drd2, Slc6a13, and Ptgs2 — with effects observed as early as one hour post-administration in rodent models.

Clinical Trial Data: Generalised Anxiety Disorder & Neurasthenia Selank's anxiolytic profile has been evaluated in a clinical study led by Zozulia and colleagues, involving 62 participants — a subset with generalised anxiety disorder (GAD) and others with neurasthenia — assessed using standardised psychometric instruments including the Clinical Global Impression (CGI) scale, the Hamilton Anxiety Rating Scale, and the Zung Self-Rating Scale. In this trial, Selank demonstrated anxiolytic efficacy comparable to the reference benzodiazepine medazepam, while additionally producing antiasthenic and psychostimulant effects that the comparator drug did not. Researchers also observed modulation of leu-enkephalin half-life in treated participants — a biochemical correlate of Selank's activity on endogenous opioid peptide metabolism — with the degree of change correlating meaningfully with baseline anxiety severity and symptom duration.

Monoaminergic & Nootropic Mechanisms Beyond the GABAergic system, Selank has been found to influence concentrations of key monoamine neurotransmitters — serotonin, dopamine, and noradrenaline — in a manner that underpins both its mood-stabilising and cognitive-enhancing effects. Research has documented Selank-induced metabolism of serotonin and modulation of dopaminergic receptor gene expression, including the dopamine D5 receptor (Drd5) — a receptor with a well-established role in long-term potentiation and the formation of memory and learning processes. Selank also appears to stimulate the noradrenergic system, which plays a central role in arousal, attention, and motivational processing — a mechanism that may contribute to the psychostimulant and anti-asthenic effects observed in clinical research.

These combined monoaminergic effects have positioned Selank as one of the more mechanistically interesting nootropic research peptides available, distinguished from other nootropics by the convergence of anxiolytic calming and cognitive stimulation within a single compound — properties that are typically pharmacologically opposing.

BDNF Upregulation & Neuroplasticity Research Selank has been found to rapidly elevate the expression of brain-derived neurotrophic factor (BDNF) in the hippocampus of rats following administration. BDNF is a member of the neurotrophin family and plays a critical role in synaptic plasticity, long-term potentiation, neurogenesis, and the consolidation of learning and memory. Its dysregulation is implicated in a range of neuropsychiatric conditions including depression, anxiety disorders, and age-related cognitive decline. Selank's capacity to upregulate hippocampal BDNF has been proposed as a key mechanism underlying both its nootropic effects and its neuroprotective activity in models of alcohol-induced cognitive impairment — where administration prevented ethanol-induced disruption of BDNF levels in the hippocampus and prefrontal cortex, alongside statistically significant improvements in object recognition memory in rodent models.

Enkephalin Protection & Endogenous Opioid Research Selank and the closely related peptide Semax have been found to inhibit enzymes responsible for the degradation of enkephalins — endogenous opioid pentapeptides that modulate pain perception, stress response, and emotional regulation. By reducing enkephalin breakdown, Selank effectively prolongs the activity of these endogenous regulatory peptides, producing analgesic and anxiolytic effects through the opioid system in parallel to its GABAergic and monoaminergic mechanisms. This enkephalin-sparing activity has been proposed as an additional contributor to Selank's anti-stress and mood-stabilising effects observed across preclinical models.

Immunomodulatory & Antiviral Research As a tuftsin analogue, Selank retains the immunomodulatory properties of its parent peptide. Research has demonstrated Selank's capacity to modulate the expression of interleukin-6 (IL-6) and to influence the balance of T helper cell cytokines, with effects on both the Th1 and Th2 arms of the adaptive immune response. Selank has also been found to significantly alter the expression of genes encoding chemokines, cytokines, and their receptors in mouse spleen tissue at six and twenty-four hours post-administration. Additionally, Selank has been investigated for antiviral activity — including studies examining its effects on influenza replication — positioning it as a compound of interest in immunology research beyond its well-established neuropsychiatric profile.

Neuroprotection & Anti-inflammatory Activity Selank has demonstrated neuroprotective effects in multiple preclinical models, attributed in part to its anti-inflammatory activity within the central nervous system. Research has shown Selank-induced changes in the expression of genes involved in inflammatory processes in the hippocampus and spleen of rodents, suggesting a capacity to modulate neuroinflammatory cascades that contribute to neurodegeneration and cognitive impairment. Its antioxidant properties and effects on BDNF further reinforce its preclinical profile as a neuroprotective research tool.

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Product Specifications

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Quality & Purity Assurance

Every batch of our Selank undergoes a comprehensive multi-stage quality control process prior to release. Our assurance pipeline includes:

• HPLC Analysis — confirms peptide purity exceeding 99%
• Mass Spectrometry (MS) — verifies molecular identity, sequence integrity, and molecular weight
• Endotoxin Testing — ensures the product is free from bacterial endotoxins
• Certificate of Analysis (CoA) — available for every batch upon request

Full batch traceability is maintained across synthesis, purification, and quality testing, providing researchers with the confidence required for reproducible, high-quality experimental outcomes.

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Handling & Reconstitution (Research Use)

Selank lyophilised powder is readily soluble in sterile bacteriostatic water or phosphate-buffered saline (PBS). Gently swirl to dissolve — do not vortex. Once reconstituted, aliquot immediately and store at –20°C. Avoid repeated freeze-thaw cycles to preserve peptide integrity. Note that Selank is not orally bioavailable due to rapid enzymatic degradation in the gastrointestinal tract; preclinical research protocols have most commonly employed intranasal or intraperitoneal administration routes in animal models, which should be considered when designing in vivo experimental protocols.

All handling should comply with standard laboratory safety protocols and applicable institutional or regulatory guidelines.

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Selank in the Context of the Research Peptide Catalogue

Selank occupies a distinct and complementary niche within our research catalogue as the only compound with a primary focus on central nervous system research — spanning anxiolytic pharmacology, nootropic biology, neuroimmunology, and BDNF-mediated neuroplasticity. It is closely related to Semax — another tuftsin-derived neuropeptide also developed by the Institute of Molecular Genetics — which shares some mechanistic overlap but differs in emphasis, with Semax research more focused on ACTH-related neuroprotection and cognitive enhancement rather than anxiolysis.

Within the broader catalogue, Selank's neuroinflammatory and immunomodulatory research applications provide a complementary perspective to the systemic tissue repair focus of BPC-157 and TB-500, the dermal and genomic remodelling activity of GHK-Cu, the mitochondrial metabolic biology of MOTS-c, the systemic hormonal signalling of retatrutide, the intracellular NAD+ and sarcopenia-focused research applications of 5-Amino-1MQ, and the endocrine and anabolic reference standard role of HGH. Together, these eight compounds span an exceptionally broad mechanistic range — from intracellular energy metabolism to systemic hormone signalling, tissue repair, and central nervous system biology.

All peptides in our catalogue are manufactured to the same >99% purity standard and are supported by batch-specific Certificates of Analysis.

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Important Notice

This product is intended strictly for in vitro research and laboratory use only. Selank is not approved for human or veterinary use by the FDA or EMA. While Selank is approved as a pharmaceutical preparation in Russia, this research-grade product has not undergone the clinical evaluation required for therapeutic approval in Western regulatory jurisdictions. It is not a drug, supplement, or food product. This product must not be administered to humans or animals outside of appropriately approved and supervised research contexts. By purchasing this product, the buyer confirms they are a qualified researcher and will use the compound solely for lawful scientific research purposes.