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Background And Peptide Identity — 2026 Update

By Editorial Desk · published 2025-12-01 · last reviewed 2026-01-12 · Faq

This is a working overview of lyophilised powder, written for readers who want more than a one-paragraph summary but less than a textbook.

This page was last updated on 2026-01-12 and is reviewed periodically as new material appears.

Background and Peptide Identity

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.

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 Background and Peptide Chemistry

Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed as a stabilized analogue of tuftsin, a naturally occurring tetrapeptide fragment derived from the immunoglobulin heavy chain. The additional Pro-Gly-Pro segment at the carboxyl terminus is intended to slow enzymatic cleavage. The compound is usually described in the literature as a synthetic peptide with anxiolytic and cognitive-related activity, a label that reflects a research context rather than an approved therapeutic category.

Most published work on selank originates from a small number of research groups in the Russian Federation. A large share of that record appears in Russian-language journals, which limits access for readers who rely on English-indexed databases. Independent replication by laboratories outside the original research network is sparse in publicly available sources. This concentration of origin and language is a frequently noted feature when the compound is summarized in broader reviews of synthetic peptides.

Selank at a glance

PropertyValueNotes
Chemical classSynthetic heptapeptideModeled on tuftsin
Amino acid sequenceThr-Lys-Pro-Arg-Pro-Gly-ProSeven residues
Approximate molecular massAround 750 DaDepends on counter-ion and hydration
Common formsLyophilized powderAlso described as aqueous solution
Primary origin of researchRussian laboratoriesMid-1990s onward

Peptide Identity and Structure

The compound was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences during the 1980s and 1990s. The stated design goal was to retain the immunomodulatory and central nervous system activity attributed to tuftsin while improving resistance to enzymatic breakdown. Adding a proline-rich tail to the short parent peptide was a deliberate strategy, because proline residues restrict the conformations available to many peptidases. The same laboratory produced Semax, an ACTH fragment analog, and both compounds were developed in parallel as short, enzymatically stabilized peptides intended for intranasal use.

Selank is not a naturally occurring peptide and has no known endogenous counterpart in human physiology. Russian-language sources frequently call it TP-7, while English-language sources use the name Selank almost exclusively. Database indexing is uneven, partly because early reports appeared in regional journals that are not widely cataloged. Some summaries describe the material as a tuftsin analog and others as a synthetic heptapeptide; the labels overlap rather than conflict. Citing the primary sequence resolves ambiguity more reliably than the research or trade name alone.

Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter notation. Its structure consists of the immunomodulatory tetrapeptide tuftsin, Thr-Lys-Pro-Arg, extended at the carboxyl terminus by a Pro-Gly-Pro segment. The molecular formula is commonly given as C33H57N11O9, corresponding to a monoisotopic mass near 751.4 Da and an average molecular mass near 751.9 Da. All seven residues are proteinogenic amino acids, and the molecule carries no modified side chains or non-natural linkages.

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Stability, Handling, and Analytical Control

Quantification in biological matrices relies on liquid chromatography coupled to tandem mass spectrometry with stable-isotope internal standards. Low plasma concentrations and adsorption to container surfaces both complicate measurement. Solid-phase extraction is often needed to reduce matrix interference before injection. Reported limits of quantification differ widely between laboratories, which makes direct comparison of pharmacokinetic results difficult and limits meta-analysis.

Peptide bonds are vulnerable to protease attack, and Selank is no exception. Measured half-life in serum is short, on the order of minutes in several reports, which explains why intranasal administration is the common route described in the literature. Absorption across the nasal mucosa partially bypasses first-pass hepatic metabolism. Quantitative data on human bioavailability remain limited and are difficult to compare across studies.

Lyophilised material kept dry at minus 20 degrees Celsius or colder is the most stable form, and suppliers commonly state a shelf life of two years or more under those conditions. Once dissolved, degradation accelerates through hydrolysis and deamidation, particularly at alkaline pH or elevated temperature. Working solutions are usually divided into single-use aliquots to avoid repeated freeze-thaw cycles. The choice of reconstitution solvent affects both stability and the ionic strength of the final preparation.

Selank Background And Chemical Identity

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.

Naming conventions place Selank in the same research family as Semax, another Russian-developed peptide investigated for cognitive effects. The two compounds share a lineage but differ in sequence and in the biological systems proposed as their targets. Semax descends from ACTH fragments, whereas Selank descends from tuftsin. Publications sometimes identify Selank by its full peptide sequence or by laboratory codes rather than one uniform trade name. Because replication outside Russia is limited, reports on its properties are best read alongside the study design and the purity of the material tested.

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.

Background from the literature

=== 1951 === January 4: Chinese soldiers capture Seoul. March 14: United Nations forces recapture Seoul during Operation Ripper. By the end of March, they have reached the 38th Parallel, and formed a defensive line across the Korean Peninsula. March 29: Julius and Ethel Rosenberg are convicted of espionage for their role in passing atomic secrets to the Soviets during and after World War II; they were executed on June 19, 1953. April 11: U.S. President Harry S. Truman fires Douglas MacArthur from command of US forces in Korea due to him demanding nuclear weapons to be used on the enemy. April 18: The European Coal and Steel Community is formed by the Treaty of Paris. April 23: American journalist William N. Oatis is arrested in Czechoslovakia for alleged espionage. May 23: The Seventeen Point Agreement is signed between Tibet and the People's Republic of China, formally annexing Tibet into China itself. September 1: Australia, New Zealand, and the United States sign the ANZUS Treaty. This compels the three countries to cooperate on matters of defense and security in the Pacific. October 10: President Harry S. Truman signs the Mutual Security Act, announcing to the world, and its communist powers in particular, that the U.S. was prepared to provide military aid to "free peoples". November 14: President Harry Truman asks Congress for U.S. military and economic aid for the communist nation of Yugoslavia. December 12: The International Authority for the Ruhr lifts part of the remaining restrictions on German industrial production and on production capacity.

== Reviews == Jay Rayner reviewed the restaurant for The Observer after Hibiscus moved from Ludlow to London, his first time at the restaurant. While stating that elements of the meal were "very clever indeed", such as foie gras ice cream and a sausage roll he described as a "colossus", he described the desserts as a "disappointment", calling an olive oil parfait a "gloopy mess". Overall, he planned on returning to give Bosi another chance. Zoe Williams also reviewed the restaurant shortly after it arrived in London, for The Daily Telegraph. She enjoyed her visit, and was impressed with the unusual combinations of foods that worked together saying "the sheer expertise of taking a food with a range of flavours, and knowing it's in peak condition to meet four others ... it really is something". John Walsh also visited it, for The Independent, after the restaurant arrived in London, and gave the food four stars, and the ambience and service three stars; Terry Durack reviewed it for the same paper, giving the restaurant 17 out of 20. Food critics from Time Out visited the restaurant in 2009, and were "disappointed" compared to their previous visit. They thought that Bosi's food combinations just did not work, but still said that some of his desserts were "faultless". Andy Hayler gave the restaurant a score of six out of ten on his scale during his November 2011 visit.

== External links == Electron+Transport+Chain+Complex+Proteins at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Khan Academy, video lecture KEGG pathway: Oxidative phosphorylation, overlaid with genes found in Pseudomonas fluorescens Pf0-1. Click "help" for a how-to.

Sources: en.wikipedia.org

Reference notes

=== 30 July === Russia claimed to have taken the village of Pivdenne, east of Toretsk. The Ukrainian 79th Tavrian Air Assault Brigade claimed to have repelled a major Russian assault on Kurakhove, inflicting losses of 12 armored vehicles, eight tanks, nine motorcycles, and one buggy destroyed, 36 Russian soldiers killed and 32 others injured. The Ukrainian military claimed to have struck an oil depot in Russia's Kursk Oblast following an air attack.

The informal abbreviations of job titles may be a source of confusion. In the United States, medical laboratory scientist (ASCP) and medical technologists (AMT) or (AAB) are often called "med techs" (based on the era in which they were known as "medical technologists"), but this shorthand term is shared by other healthcare employees, including pharmacy techs, radiographers (also known as radiologic technologists), and respiratory therapists. In the United States there is a formal distinction between an MLT and a MT/MLS. Often, MT/MLS have at least a bachelor's degree, while MLT have an associate degree. However, due to grandfathering rules and certification requirements between the boards of registry, some MT/MLS may only have an associate degree. Scientists and technologists generally earn a higher income than technicians, have more responsibilities, and have more opportunities for advancement. In the United Kingdom, there are defined training pathways leading to professional registration as either a clinical scientist, or as a biomedical scientist. The role descriptions for these healthcare scientists are very different, where clinical scientists generally undertake non-routine research and development, as well as improving and providing clinical service using scientific expertise. Biomedical scientists in the United Kingdom are similar to the role of MLT and MT/CLS described above, and have similar regulatory requirements for professional regulation. Clinical scientists in the United Kingdom may struggle with a lack of professional recognition.

Importantly, the NPYS group can replace the Acm PG to yield an activated thiol. Using this method, Kiso and coworkers reported the first total synthesis of insulin in 1993. In this work, the A-chain of insulin was prepared with following protecting groups in place on its cysteines: CysA6(But), CysA7(Acm), and CysA11(But), leaving CysA20 unprotected.

Those in the upper jaw, twelve per side in mature individuals, were larger than their counterparts of the lower jaw, except at the rear. The largest found so far is estimated to have been 30.5 cm (12.0 in) long including the root when the animal was alive, making it the largest tooth of any carnivorous dinosaur yet found. The lower jaw was robust. Its front dentary bone bore thirteen teeth. Behind the tooth row, the lower jaw became notably taller. The upper and lower jaws of Tyrannosaurus, like those of many dinosaurs, possessed numerous foramina, or small holes in the bone. Various functions have been proposed for these foramina, such as a crocodile-like sensory system or evidence of extra-oral structures such as scales or potentially lips, with subsequent research on theropod tooth wear patterns supporting such a proposition.

Sources: en.wikipedia.org

Frequently asked questions

What type of molecule is Selank?

Selank is a synthetic peptide made of seven amino acids. It is modeled on tuftsin, a natural tetrapeptide, with an added three-residue tail. It is not a small-molecule drug.

Where was Selank developed?

It originates from research in Russia, associated with the Institute of Molecular Genetics of the Russian Academy of Sciences. The first descriptions date to the mid-1990s. Most published studies come from Russian laboratories.

Is Selank found in nature?

No, Selank itself does not occur naturally. Its backbone is based on tuftsin, which is produced in the body, but the seven-residue version is a synthetic construct. It is supplied as a manufactured peptide.

What is selank?

Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, designed as a metabolically stabilized analogue of the endogenous tetrapeptide tuftsin. It has been studied mainly against anxiety-related and cognitive endpoints rather than as an approved medicine in most jurisdictions.

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