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// Neuropeptide Research

Selank

CAS No. 129954-34-3
Molecular Formula C33H57N11O9
Molecular Weight 751.89 g/mol
Sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro

Synthetic heptapeptide derived from the immunomodulatory tetrapeptide tuftsin and extended with a Pro-Gly-Pro stabilising tail. Studied in preclinical research for GABAergic modulation, BDNF regulation, and dual neurological / immunomodulatory signalling.

// 01 — Mechanism

Mechanism of Action

Selank is a synthetic heptapeptide (Thr-Lys-Pro-Arg-Pro-Gly-Pro) designed around the immunomodulatory tetrapeptide tuftsin — a proteolytic fragment of the immunoglobulin G Fc region whose active sequence Thr-Lys-Pro-Arg is reproduced at the Selank N-terminus. The C-terminal Pro-Gly-Pro extension stabilises the peptide against enzymatic hydrolysis and has enabled investigation of intranasal administration routes that would otherwise rapidly inactivate native tuftsin.

Selank retains tuftsin-derived immunomodulatory activity: published work describes effects on cytokine balance, including modulation of interleukin-6 (IL-6) and interferon responses, and effects on lymphocyte function consistent with its parent sequence. However, the majority of Selank research has focused on central nervous system pathways, particularly in the context of anxiety-related signalling.

Mechanistically, Selank is generally described as an indirect modulator of GABAergic neurotransmission rather than a direct GABA receptor ligand. Reported mechanisms include modulation of GABA-related gene expression in rodent brain tissue, upregulation of brain-derived neurotrophic factor (BDNF), and effects on serotonergic metabolism including changes in the ratio of 5-hydroxyindoleacetic acid (5-HIAA) to serotonin. Inhibition of enkephalinase and related peptidases has been described as a peripheral mechanism relevant to Selank activity.

// 02 — Research Findings

Key Research Findings

  1. Anxiolytic-profile behavioural effects have been described in classical rodent anxiety paradigms including the elevated plus-maze and open-field tests following Selank administration. Ashmarin research group, Institute of Molecular Genetics RAS, Selank behavioural pharmacology literature.
  2. Upregulation of hippocampal BDNF mRNA and protein following Selank administration has been reported in rat models, consistent with effects described for other anxiolytic research compounds. Inozemtseva, Kolomin and colleagues, Selank molecular neurobiology literature, Russian Academy of Sciences.
  3. Peripheral immunomodulatory effects, including modulation of IL-6 and effects on lymphocyte proliferation, have been documented and are consistent with Selank's tuftsin-derived lineage. Ashmarin and colleagues, tuftsin-derived peptide immunology literature.
  4. Effects on serotonergic metabolism, including changes in 5-hydroxyindoleacetic acid (5-HIAA) levels and serotonin turnover in specific brain regions, have been described across published studies. Russian Academy of Sciences groups, Selank monoaminergic neurochemistry literature.
  5. Inhibition of enkephalinase and related neuropeptidases has been characterised in biochemical assays and is proposed to contribute to peripheral enkephalin signalling modulation. Ashmarin research group, regulatory peptide enzymatic-degradation literature.

Citations last reviewed: 1 October 2026

// 03 — Specifications

As Supplied by BasedPeps

Molecular Weight 751.89 g/mol
Purity ≥99% HPLC · mass spectrometric identity confirmed
Sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro (heptapeptide)
Storage Lyophilised at −20 °C · reconstituted at 2–8 °C
Format Lyophilised white powder · also available as intranasal solution (10 mg/mL, aqueous) for in-vitro and preclinical intranasal-administration research models
Documentation Third-party CoA available on request
Use In-vitro / in-vivo research only — not for human administration
// 04 — FAQ

Researcher FAQ

What is Selank?

Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. Its first four residues correspond to the immunomodulatory endogenous peptide tuftsin. A C-terminal Pro-Gly-Pro extension confers resistance to enzymatic degradation and has enabled investigation of intranasal administration routes in preclinical research.

How is Selank related to tuftsin?

The N-terminal four residues of Selank reproduce the active sequence of tuftsin (Thr-Lys-Pro-Arg), a tetrapeptide fragment of the Fc region of immunoglobulin G known for immunomodulatory activity. The C-terminal Pro-Gly-Pro extension stabilises Selank against peptidase hydrolysis compared with native tuftsin.

Does Selank bind directly to GABA receptors?

Selank is generally described in published literature as an indirect modulator of GABAergic transmission rather than a direct GABA receptor ligand. Proposed mechanisms include modulation of GABA-related gene expression and interaction with endogenous anxiolytic signalling systems.

How is Selank reconstituted for laboratory use?

Selank is supplied as a lyophilised white powder. Reconstitution in sterile bacteriostatic water or 0.9% sodium chloride is standard in research protocols, with gentle swirling until fully dissolved. Once reconstituted the peptide is typically stored at 2–8 °C.

Is a Certificate of Analysis provided?

Yes. BasedPeps publishes a third-party Certificate of Analysis per lot documenting HPLC purity (≥99%) and mass spectrometric identity confirmation. Certificates are available on the product page.

View BasedPeps Selank

Research-grade Selank. Third-party HPLC and mass spectrometry verification per lot. Certificate of Analysis available on request. Dispatched from Riga, Latvia within 24 hours.

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