Buy Selank — The Tuftsin-Derived Heptapeptide for Anxiolytic, Nootropic, and Neuroprotective Research

Selank (Thr-Lys-Pro-Arg-Pro-Gly-Pro) is a synthetic heptapeptide analog of the endogenous immunomodulatory peptide tuftsin. Researchers study it extensively for its anxiolytic, nootropic, and neuroprotective properties, making it a benchmark compound in neuropeptide research. Consequently, it has become one of the most investigated peptides in the Russian neuropharmacology lineage alongside Semax. Browse for more peptides

What Is Selank?

Selank is a synthetic seven-amino-acid peptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. Scientists originally developed Selank at the Institute of Molecular Genetics of the Russian Academy of Sciences, and they designed it as a structural analog of tuftsin, an endogenous tetrapeptide (Thr-Lys-Pro-Arg) produced by enzymatic cleavage of immunoglobulin G. Moreover, the C-terminal Pro-Gly-Pro extension significantly increases metabolic stability and alters CNS activity compared to the parent tuftsin molecule. Russia approved Selank for generalized anxiety disorder and neurasthenia, and it remains the only peptide anxiolytic in this class with regulatory approval anywhere in the world.

Unlike benzodiazepines, which bind directly to the GABA-A receptor and can suppress natural GABA function over time, Selank enhances GABA-A sensitivity without replacing the endogenous signal. Therefore, researchers study it as a potential anxiolytic that avoids the sedation, amnesia, and physical dependence associated with classical benzodiazepines.

How Does Selank Work?

Selank modulates CNS function through several interconnected mechanisms that center on GABAergic neurotransmission, enkephalin regulation, and neurotrophic factor expression.

Positive Allosteric Modulation of GABA-A Receptors

Selank functions as a positive allosteric modulator of GABA-A receptors. It does not bind to the primary GABA binding site but rather to a distinct, allosteric site on the receptor complex. This binding enhances the effect of GABA, potentiating the inhibitory response. As a result, radioligand binding assays using [3H]GABA have shown that Selank can increase the number of specific binding sites for GABA (Bmax) without significantly affecting the receptor’s affinity for GABA (Kd). Furthermore, a 2018 radioligand study published in Protein and Peptide Letters confirmed that Selank enhances GABA binding without engaging the benzodiazepine site, which distinguishes its mechanism from that of classical anxiolytics.

Inhibition of Enkephalin-Degrading Enzymes

Enkephalins are endogenous opioid peptides that play a role in pain modulation and emotional regulation, and their signaling terminates through rapid degradation by enkephalinases. Selank inhibits these enzymes, thereby prolonging the action of endogenous enkephalins. Additionally, clinical studies in patients with generalized anxiety disorder have shown a correlation between the anxiolytic effect of Selank and an increase in the half-life of leu-enkephalin in the blood. The reported IC50 for enkephalinase inhibition is approximately 15–20 μM.

BDNF and Neurotrophic Factor Regulation

Selank regulates gene expression, including that of brain-derived neurotrophic factor (BDNF), which is critical for neuronal development, synaptic plasticity, and cognitive function. Whereas Semax produces a pronounced ~3-fold BDNF mRNA increase in the hippocampus, Selank prevents ethanol-induced BDNF changes and modulates neurotrophic signaling through a distinct regulatory profile. Notably, a 2016 rat study analyzing 84 neurotransmission-related genes in the frontal cortex found that 45 genes showed significant expression changes at 1 hour post-administration and 22 at 3 hours, with a positive correlation between Selank- and GABA-induced changes.

Neuroprotective and Immunomodulatory Effects

Selank exerts neuroprotective effects in models of cerebral ischemia. A 2026 transcriptomic study using a rat middle cerebral artery occlusion (tMCAO) model identified 118 differentially expressed genes after Selank administration, most of which were downregulated in response to the peptide. Furthermore, 60 genes that ischemia alone upregulated (including C1qc, Cd68, Cd74, and RT1-Ba) were suppressed by Selank, demonstrating a compensatory effect on ischemia-induced gene expression disturbances. The study also revealed Selank activity toward genes involved in neuroreception and immunity, including antigen processing and complement system pathways.

Key Research Applications

Researchers study Selank across a broad range of preclinical and clinical neurological models.

• Anxiety and stress-related disorder research (GABA-A allosteric modulation)

• Cognitive function and nootropic investigations (BDNF regulation, memory processes)

• Neuroprotection and cerebral ischemia studies (tMCAO models, gene expression)

• Immunomodulation and anti-inflammatory pathway research (cytokine regulation, Il2rg, Xcr1)

• Enkephalin signaling and pain modulation investigations (enkephalinase inhibition)

• Opioid and alcohol withdrawal and dependence models

When you Buy Selank from our catalog, you receive a high-purity lyophilized research peptide available in 10mg and 20mg vial configurations. We test every batch independently to ≥99% purity by HPLC, and we confirm identity through third-party mass spectrometry against the theoretical mass of 751.87 g/mol. In addition, each batch undergoes LAL endotoxin testing, heavy metals screening, and microbial limit testing. We include batch-specific Certificates of Analysis for full research transparency.

Frequently Asked Questions

What is Selank used for in research?

Researchers use Selank in laboratory studies of anxiety, cognitive function, neuroprotection, immunomodulation, and enkephalin signaling. However, it is not FDA-approved for any indication in the United States.

How should I store Selank?

Store the lyophilized vial at −20°C in a desiccated environment and protect it from light. After reconstitution, refrigerate the solution at 2–8°C and avoid repeated freeze-thaw cycles.

What purity should I expect?

We test every batch to ≥99% purity by HPLC. We ship a batch-specific Certificate of Analysis with each order, and it covers HPLC purity, mass spectrometry identity, endotoxin levels, and heavy metals screening.

What is the difference between Selank and Semax?

Selank derives from tuftsin and primarily modulates GABAergic signaling and enkephalin pathways for anxiolytic research. Semax derives from ACTH(4-7) and primarily upregulates BDNF and NGF for cognitive and neuroprotective research. Whereas Selank targets anxiolytic mechanisms, Semax targets neurotrophic factor expression.

Does Selank cause sedation?

No. In comparator-controlled Russian trials, Selank produced anxiolytic activity without sedation. Animal studies further demonstrate that Selank enhances the anxiolytic effect of benzodiazepines while weakening their sedative and muscle relaxant effects. However, no Western randomized controlled trials have replicated these findings.

Important Research Disclaimer

This product is intended strictly for laboratory research use only. It is not for human or veterinary use, and not for diagnostic or therapeutic applications. As of 2026, Selank remains unapproved by the FDA for any indication, though Russia approved it for generalized anxiety disorder and neurasthenia. The FDA classified Selank as a Category 2 bulk drug substance in April 2026, which restricts compounding pending further review. No Western randomized controlled trials have been completed, and the available human data derive primarily from Russian clinical studies that independent Western populations have not replicated. Therefore, no one outside an institutional research setting should handle or use Selank. Qualified researchers should handle all peptides in accordance with institutional safety guidelines and applicable regulations.

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