NovaWell.
Selank research vial
Sequence length
7 AA
Molecular weight
751.9 g/mol (parent heptapeptide); higher for N-acetyl/amidate analogue
Current batch
SELAN202606
Nootropics · Anxiolytic / Neuropeptide research

Selank

Synthetic heptapeptide derived from Tuftsin, studied for anxiolytic and immunomodulatory pathways

N-Acetyl Selank (10mg vials)

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Specifications

Molecular weight751.9 g/mol (parent heptapeptide); higher for N-acetyl/amidate analogue
Sequence length7 amino acids
Amino acid sequenceThr-Lys-Pro-Arg-Pro-Gly-Pro
AppearanceWhite lyophilized powder
SolubilityBacteriostatic water; sterile water
Storage (lyophilized)-20°C, protected from light
Storage (reconstituted)2–8°C, use within 28 days
Half-lifeShort systemic half-life for parent peptide; N-acetylation and C-terminal amidation extend stability against exopeptidases in published in vitro work
Current batch purity99.72% (HPLC) · SELAN202606

Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, developed at the Institute of Molecular Genetics of the Russian Academy of Sciences. It is a stabilised analogue of the immunomodulatory tetrapeptide Tuftsin (Thr-Lys-Pro-Arg) — the first four residues of Selank are the Tuftsin sequence, extended at the C-terminus with Pro-Gly-Pro to slow enzymatic degradation. The parent heptapeptide has a molecular weight of approximately 751.9 g/mol (C33H57N11O9). NovaWell supplies the NA Selank Amidate analogue (N-acetyl at the N-terminus, C-terminal amide), a backbone-modified form widely used in in vitro stability research. Material is supplied as a lyophilized powder, third-party tested for purity and endotoxin conformance, for laboratory research use only.

Research Studies

The following studies are summarized for educational purposes only. Inclusion does not imply any human use; all referenced research was conducted in vitro, in animal models, or as clinical observation cited from the published literature.

Research study

The inhibitory effect of Selank on enkephalin-degrading enzymes as a possible mechanism of its anxiolytic activity

Zozulya AA, Kost NV, Sokolov OYu, Gabaeva MV, Grivennikov IA, Andreeva LN, Zolotarev YA, Ivanov SV, Andryushchenko AV, Myasoedov NF, Smulevich AB. Bull Exp Biol Med. 2001;131(4):315–317. View source ↗

Scientific findings

This study combined an in vitro enzymology arm with a clinical observation arm. The authors first characterised enkephalin-degrading enzyme activity in the plasma of patients with generalized anxiety disorder, panic disorder, and agoraphobia (DSM-IV criteria), reporting a shortened enkephalin half-life and reduced total enkephalinase activity in the generalized-anxiety cohort relative to controls. The heptapeptide Selank (Thr-Lys-Pro-Arg-Pro-Gly-Pro) then dose-dependently inhibited enzymatic hydrolysis of plasma enkephalin in vitro, with an IC50 of approximately 15 μM, and was more potent in this assay than the reference peptidase inhibitors bacitracin and puromycin. The authors propose that Selank's reported anxiolytic activity may be linked to its inhibition of enkephalin breakdown, allowing endogenous enkephalin signalling to persist longer in plasma.

Plain English

The body naturally makes small molecules called enkephalins that help dampen stress signals. Enzymes in the blood break these enkephalins down quickly. The researchers showed that, in test-tube experiments, Selank slows those breakdown enzymes — making it more effective than two well-known reference inhibitors. They also noted that patients with generalized anxiety had unusually fast enkephalin breakdown to begin with. The proposal: Selank may help keep the body's own calming signals around for longer, rather than acting like a sedative.

Research study

GABA, Selank, and Olanzapine Affect the Expression of Genes Involved in GABAergic Neurotransmission in IMR-32 Cells

Filatova E, Kasian A, Kolomin T, Rybalkina E, Alieva A, Andreeva L, Limborska S, Myasoedov N, Pavlova G, Slominsky P, Shadrina M. Front Pharmacol. 2017;8:89. View source ↗

Scientific findings

Using qPCR across a panel of 84 genes involved in GABAergic neurotransmission in cultured IMR-32 neuroblastoma cells, the authors compared expression changes induced by GABA, Selank, and olanzapine. Selank alone did not significantly change the mRNA level of the GABA-related genes in this cell line, suggesting that Selank does not act as a direct transcriptional regulator of the GABAergic gene set in IMR-32 cells. The authors interpret this in the context of prior literature showing in vivo effects of Selank on GABAergic signalling, and propose that Selank's interaction with the GABAergic system in intact tissue may occur through allosteric or indirect mechanisms rather than direct gene-expression modulation in neurons.

Plain English

GABA is the brain's main calming neurotransmitter. The researchers wanted to know whether Selank changes how strongly nerve cells turn on the genes that handle GABA signalling. In a human neuron-like cell line, Selank by itself did not change those gene levels in a measurable way. The authors suggest Selank probably influences the GABA system indirectly — perhaps by changing how existing receptors respond to GABA — rather than by reprogramming the cell's gene activity.

Storage & handling

Lyophilized (unreconstituted): Store at -20°C, protected from light. Stable for 24+ months under correct storage. Avoid repeated temperature cycling.

Reconstituted: Dissolve in bacteriostatic water (typically 1–2 mL per 10 mg vial, depending on the research protocol). Store reconstituted solution at 2–8°C and use within 28 days. Do not freeze reconstituted solution.

Vial format: 10 mg lyophilized, vacuum-sealed glass vial with rubber stopper and aluminum crimp. Sterility tested per USP guidelines.

Shipping: Lyophilized NA Selank Amidate is stable at ambient temperature for the typical 1–3 day shipping window. Cold-pack shipping available on request.

Frequently asked questions

What peptide sequence is Selank?+

Selank is the 7-amino-acid sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro (TKPRPGP), with a molecular formula of C33H57N11O9 and a molecular weight of approximately 751.9 g/mol for the parent heptapeptide. The first four residues (Thr-Lys-Pro-Arg) are the immunomodulatory tetrapeptide Tuftsin. The NA Selank Amidate analogue supplied by NovaWell carries an N-terminal acetyl group and a C-terminal amide; both modifications are widely reported in the peptide-chemistry literature as a way to slow exopeptidase degradation.

How is Selank related to Tuftsin?+

Tuftsin (Thr-Lys-Pro-Arg) is a natural tetrapeptide identified as a fragment of the heavy chain of immunoglobulin G. Selank was designed at the Russian Institute of Molecular Genetics by extending the Tuftsin sequence at the C-terminus with the tripeptide Pro-Gly-Pro. The added Pro-Gly-Pro tail is reported in the published literature to substantially slow enzymatic degradation of the molecule, giving Selank a longer functional window than Tuftsin in pharmacology studies.

What mechanism is Selank studied for?+

Two pathways dominate the published Selank literature. First, Zozulya, Kost and colleagues (Bull Exp Biol Med, 2001) reported that Selank inhibits plasma enkephalin-degrading enzymes in vitro with an IC50 near 15 μM, suggesting an indirect modulation of endogenous opioid signalling. Second, Filatova and colleagues (Front Pharmacol, 2017) examined Selank's effect on the GABAergic gene-expression program in cultured neurons and concluded that Selank likely interacts with the GABAergic system through allosteric or indirect routes rather than direct transcriptional control. Selank is also reported in the Russian literature to modulate BDNF expression in rat hippocampus after intranasal administration.

What does NovaWell test Selank for?+

Every batch of NA Selank Amidate supplied by NovaWell is tested by an independent third-party laboratory for: identity and purity (HPLC + MS), bacterial endotoxin (USP <85>), heavy metals (USP), and sterility (USP). The Certificate of Analysis for the currently shipping batch is linked from the Certificates tab on this page, alongside the test date and laboratory ID.

How should Selank be stored after reconstitution?+

Once reconstituted in bacteriostatic water, Selank should be stored at 2–8°C and used within 28 days. Do not freeze reconstituted solution. The lyophilized powder is stable at -20°C for 24+ months when protected from light and moisture.

Where does NovaWell source Selank?+

NovaWell sources NA Selank Amidate from a vetted synthesis partner under our supplier qualification protocol, which includes facility audits and review of internal QC documentation. Every batch is then independently verified by a third-party laboratory before release. The manufacturer ID for the currently shipping batch is listed in the Description tab.