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Selank Background And Chemical Identity — What the Evidence Shows

By Editorial Desk · published 2026-01-03 · last reviewed 2026-02-10 · Info

The short version of anxiolytic fits in a sentence. The long version — which is the one that helps — is below.

Reviewed 2026-02-10. Anything still debated is marked as such rather than presented as settled.

Selank Background And Chemical Identity

Selank is a synthetic heptapeptide developed in Russia during the 1990s. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences designed it as a stabilized analog of tuftsin, a naturally occurring immunomodulatory tetrapeptide. The compound has been studied primarily for its reported anxiolytic and nootropic effects. It remains largely unknown in Western pharmacology and is not approved as a medicine by major regulators such as the FDA or the EMA.

The primary structure of Selank is Thr-Lys-Pro-Arg-Pro-Gly-Pro, corresponding to the molecular formula C33H57N11O9 and a monoisotopic mass of roughly 751.9 daltons. The N-terminal threonine and the arginine residue in the fourth position are shared with tuftsin, which carries the sequence Thr-Lys-Pro-Arg. The three additional residues at the C-terminus, Pro-Gly-Pro, extend the chain and are associated with greater resistance to enzymatic degradation. This extension also separates Selank from the shorter parent peptide.

Mechanism and Evidence Status

Proposed mechanisms centre on the GABAergic system. Animal and tissue studies report changes in GABA-A receptor expression and reduced activity of GABA transaminase, the enzyme that degrades GABA. Effects on monoamine turnover, including serotonin and dopamine pathways, are also described, and a separate line of work links the peptide to increased expression of brain-derived neurotrophic factor in hippocampal tissue. Most of these findings come from rodent models and cell preparations. How the individual observations combine into a single coherent mode of action is not settled.

Pharmacokinetic data are sparse and largely derived from animal work. After intranasal administration the peptide appears in plasma within minutes, and reported half-lives are short, on the order of minutes to tens of minutes. Degradation proceeds through ordinary proteolytic cleavage into constituent amino acids and smaller fragments. Direct evidence that intact Selank reaches brain tissue in meaningful amounts is limited, and the extent of blood-brain barrier penetration is debated. Some authors argue that fragments, not the parent peptide, carry much of the observed activity.

Selank at a glance

PropertyValueNotes
Molecular classSynthetic heptapeptideStabilized analog of tuftsin
SequenceThr-Lys-Pro-Arg-Pro-Gly-ProSingle-letter form: TKPRPGP
Molecular formulaC33H57N11O9Monoisotopic mass about 751.9 Da
AppearanceWhite to off-white powderTypically supplied as lyophilized solid
SolubilityFreely soluble in waterAlso soluble in common polar solvents

Origins and Proposed Mechanisms

Proposed mechanisms centre on modulation of the GABAergic system, with reports of altered expression of genes related to GABA-A receptor subunits and changed monoamine turnover. Some studies describe inhibition of enkephalinase, the enzyme that degrades endogenous enkephalins, which may prolong opioid peptide signalling. Effects on brain-derived neurotrophic factor and on cytokine expression have also been reported. These findings come largely from animal models and small human studies, and the precise primary target remains unresolved.

Published clinical evidence is limited. Most controlled trials were conducted in Russia, enrolled modest numbers of participants, and appeared in Russian-language journals, which restricts independent verification. Reported outcomes include lower anxiety scores, improved attention and memory measures, and changes in fatigue ratings. Reviews written in English note methodological limitations such as small samples and inconsistent endpoints. Whether the compound produces clinically meaningful benefit relative to established anxiolytics is therefore an open question rather than an established finding.

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Background and Peptide Identity

Tuftsin, the parent structure, is a naturally occurring immunomodulatory tetrapeptide released from the Fc region of immunoglobulin G by spleen enzymes. Selank extends this four-residue sequence with three additional amino acids. The stated rationale is that the added tail slows enzymatic breakdown and may influence receptor interactions. How the full heptapeptide behaves at the molecular level is not firmly established, and proposed mechanisms often involve indirect modulation of neurotransmitter or immune signaling rather than a single defined target.

Selank is a synthetic heptapeptide developed in Russia. Its sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, a seven-residue chain built around the natural tetrapeptide tuftsin. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences first described the compound in the mid-1990s. The design combined the tuftsin core with an added Pro-Gly-Pro tail, a modification intended to extend the molecule's stability in biological fluids. Published work on the peptide has appeared mainly in Russian-language journals.

Reported activity for Selank centers on anxiolytic and nootropic effects. Russian clinical reports describe use in anxiety and in cognitive or attention-related complaints. Most of this evidence comes from studies conducted by the same research groups that developed the peptide. Independent replication in other countries remains limited, and no major Western regulatory agency has approved the compound for any indication. The gap between local reports and external verification is a recurring point in discussions of the peptide.

Reference notes

GLD-2 (which stands for Germ Line Development 2) is an enzyme which in humans is encoded by the gene TENT2. More specifically, it is a cytoplasmic poly(A) polymerase (cytoPAPs) which adds successive AMP monomers to the 3’ end of specific RNAs, forming a poly(A) tail, which is a process known as polyadenylation. For RNA specificity, GLD-2 associates with an RNA-binding protein, typically a GLD-3, to form a heterodimer that acts as a cytoplasmic PAP. This protein has an enzymatic function and belongs to a family (DNA polymerase type-B-like family) which includes several similar enzymes such as GLD-1, GLD-3 and GLD-4. This family of cytoplasmic PAPs has been described in several different species including Homo sapiens, Caenorhabditis elegans, Xenopus, Mus musculus and Drosophila. Moreover, as it is a cytoplasmtaic PAP it differs from nuclear PAPs in some aspects. While nuclear PAPs contain a catalytic domain and an RNA-binding domain, GLD-2 family members have only a catalytic domain.

Activated carbon, in 50% w/w combination with celite, is used as stationary phase in low-pressure chromatographic separation of carbohydrates (mono-, di-, tri-saccharides) using ethanol solutions (5–50%) as mobile phase in analytical or preparative protocols. Activated carbon is useful for extracting the direct oral anticoagulants (DOACs) such as dabigatran, apixaban, rivaroxaban and edoxaban from blood plasma samples. For this purpose it has been made into "minitablets", each containing 5 mg activated carbon for treating 1ml samples of DOAC. Since this activated carbon has no effect on blood clotting factors, heparin or most other anticoagulants this allows a plasma sample to be analyzed for abnormalities otherwise affected by the DOACs. Carbon adsorption has numerous applications in removing pollutants from air or water streams both in the field and in industrial processes such as:

A carboxylic acid has the general formula R-C(O)OH, where R is an organic radical. The carboxyl group -C(O)OH contains a carbonyl group, C=O, and a hydroxyl group, O-H. Acetic acid (CH3COOH) Citric acid (C6H8O7) Formic acid (HCOOH) Gluconic acid HOCH2-(CHOH)4-COOH Lactic acid (CH3-CHOH-COOH) Oxalic acid (HOOC-COOH) Tartaric acid (HOOC-CHOH-CHOH-COOH) Halogenation at alpha position increases acid strength, so that the following acids are all stronger than acetic acid. Fluoroacetic acid Trifluoroacetic acid Chloroacetic acid Dichloroacetic acid Trichloroacetic acid Normal carboxylic acids are the direct union of a carbonyl group and a hydroxyl group. In vinylogous carboxylic acids, a carbon-carbon double bond separates the carbonyl and hydroxyl groups. Ascorbic acid Deoxyribonucleic acid (DNA) Ribonucleic acid (RNA) Listing of strengths of common acids and bases Zumdahl, Steven S. (1997). Chemistry (4th ed.). Boston: Houghton Mifflin. ISBN 9780669417944. Pavia, D. L.; Lampman, G. M.; Kriz, G. S. (2004). Organic Chemistry Volume I. Mason, OH: Cengage Learning. ISBN 0759347271.

Sources: en.wikipedia.org

Notes from published material

After translation, the AGP protein backbones are highly decorated with complex carbohydrates, primarily type II AG polysaccharides. The biosynthesis of the mature AGP involves cleavage of the signal peptide at the N-terminus, hydroxylation on the P residues and subsequent glycosylation and in many cases addition of a GPI-anchor. Glycosylation of the AGP backbone is suggested to initiate in the ERTooltip endoplasmic reticulum with the addition of first Gal by O-galactosyltransferase, which is predominantly located in ER fractions. Chain extension then occurs primarily in the GA. For those AGPs that include a GPI anchor, addition occurs while co-translationally migrating into the ER.

The methyl ricinoleate is converted to heptanal and methyl undecenoate by combining with steam in a cracking furnace at 400 - 575 °C. The cleavage of the aliphatic chain occurs selectively between the hydroxymethylene and the allyl-methylene group. Besides heptanal and methyl undecenoate, a mixture of methyl esters of saturated and unsaturated C18-carboxylic acids is obtained. This mixture is known under the trade name Esterol and is used as a lubricant additive. The methyl ester is next hydrolyzed to give 10-undecenoic acid (undecylenic acid). The undecenoic acid is dissolved in toluene and, in the presence of the radical initiator benzoyl peroxide (BPO), gaseous hydrogen bromide is added, in contrary to the Markovnikov rule ("anti-Markovnikov"). When cooled to 0 °C, the fast and highly exothermic reaction produces 11-bromoundecanoic acid in 95% yield - the Markovnikov product 10-bromoundecanoic acid is produced in small quantities as a by-product. Toluene and unreacted hydrogen bromide are extracted under reduced pressure and reused.

Hippocrates in his writings discussed the use of silver in wound care. At the beginning of the twentieth century surgeons routinely used silver sutures to reduce the risk of infection. In the early 20th century, physicians used silver-containing eyedrops to treat ophthalmic problems, for various infections, and sometimes internally for diseases such as tropical sprue, epilepsy, gonorrhea, and the common cold. During World War I, soldiers used silver leaf to treat infected wounds. In the 1840s, founder of gynecology J. Marion Sims employed silver wire, which he had a jeweler fashion, as a suture in gynecological surgery. This produced very favorable results when compared with its predecessors, silk and catgut. Prior to the introduction of modern antibiotics, colloidal silver was used as a germicide and disinfectant. With the development of modern antibiotics in the 1940s, the use of silver as an antimicrobial agent diminished, although it retains some use in medicinal compounds today. Silver sulfadiazine (SSD) is a compound containing silver and the antibiotic sodium sulfadiazine, which was developed in 1968.

5-Oxo-ETE and 5-oxo-15(S)-hydroxy-ETE but not 5-hydroxy members of the 5-HETE family such as 5-(S)-HETE activate peroxisome proliferator-activated receptor gamma (PPARγ). This activation does not proceed through OXER1; rather, it involves the direct binding of the oxo analog to PPARγ with 5-oxo-15-(S)-hydroxy-ETE being more potent than 5-oxo-ETE in binding and activating PPARγ. The Activation of OXER1 receptor and PPARγ by the oxo analogs can have opposing effects on cell function. For example, 5-oxo-ETE-bound OXER1 stimulates whereas 5-oxo-ETE-bound PPARγ inhibits the proliferation of various types of human cancer cell lines; this results in 5-oxo-ETE and 5-oxo-15-(S)-HETE having considerably less potency than anticipated in stimulating these cancer cells to proliferate relative to the potency of 5-(S)-HETE, a relationship not closely following the potencies of these three compounds in activating OXER1. 5-Oxo-ETE relaxes pre-contracted human bronchi by a mechanism that does not appear to involve OXER1 but is otherwise undefined.

Sources: en.wikipedia.org

Frequently asked questions

What is Selank?

Selank is a synthetic heptapeptide designed as a stabilized analog of the natural tetrapeptide tuftsin. It has been investigated mainly for anxiolytic and cognitive effects. It is not an approved pharmaceutical in most countries.

Where was Selank developed?

It was developed in Russia, at the Institute of Molecular Genetics of the Russian Academy of Sciences, during the 1990s. Most published research originates from Russian institutions. Independent international replication remains limited.

How does Selank differ from tuftsin?

Tuftsin is a natural tetrapeptide with the sequence Thr-Lys-Pro-Arg that participates in immune signaling. Selank extends that sequence with Pro-Gly-Pro at the C-terminus. The added residues are linked to greater resistance to enzymatic breakdown.

What mechanisms are proposed for Selank?

Reports describe modulation of GABA signalling, changes in monoamine turnover and effects on neurotrophic factor expression. These observations come mainly from animal and cell studies. A single unifying mechanism has not been demonstrated.

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