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Background And Peptide Identity — Deep Dive

By Editorial Desk · published 2025-12-11 · last reviewed 2026-01-24 · Topic

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

This page was last updated on 2026-01-24 and is reviewed periodically as new material appears.

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.

Mechanism and Evidence Base

Clinical evidence comes mainly from small studies conducted in Russia, several of which were open-label or lacked robust blinding. Reported outcomes include lower anxiety scores, changes in attention measures, and effects on asthenic states following illness. Sample sizes are typically in the tens of participants, and independent replication outside the region is scarce. Reviews published in English generally note the limited methodological quality of the underlying trials. Whether the compound produces clinically meaningful effects under rigorous conditions remains unresolved.

Proposed mechanisms center on modulation of the GABA system, but no single molecular target has been confirmed. Rodent studies report changes in GABA-A receptor expression and in the turnover of serotonin, dopamine, and norepinephrine in several brain regions. Increases in brain-derived neurotrophic factor and its receptor have also been described after repeated administration. These findings come largely from animal models, and the degree to which they describe human neurochemistry remains an open question. The mechanism is best characterized as multi-system and not fully resolved.

Pharmacokinetic data are limited. Like most short peptides, Selank is vulnerable to plasma and tissue peptidases, and its measured half-life in circulation is short, on a minutes scale. The Pro-Gly-Pro tail slows this degradation but does not eliminate it. Intranasal administration is the route described in most reports, with absorption through the nasal mucosa and a hypothesized path into the central nervous system that avoids the blood-brain barrier. Direct measurements of human brain exposure are unavailable, so distribution claims rest on inference from animal work.

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

Selank Origin and Chemical Identity

Regulatory status differs sharply by region. Selank holds a Russian marketing authorization, where it is supplied mainly as nasal drops, while authorities elsewhere have not approved it for medical use. Material sold internationally is therefore usually labeled as a research chemical rather than a medicine. Peer-reviewed publications come predominantly from Russian laboratories, and sample sizes are generally small. Whether the compound produces comparable effects under independent, well-controlled replication remains an open question that the broader literature has not settled.

Selank is a synthetic heptapeptide developed in Russia as a structural analogue of tuftsin, a naturally occurring immunomodulatory tetrapeptide. Its sequence, Thr-Lys-Pro-Arg-Pro-Gly-Pro, keeps the tuftsin core at the N-terminus and appends a Pro-Gly-Pro tail. Researchers at the Institute of Molecular Genetics in Moscow synthesized the compound during the 1990s while searching for peptides with combined anxiolytic and immunomodulatory activity. The added tail was intended to resist enzymatic cleavage and prolong the molecule's presence in circulation.

The compound has a calculated molecular weight near 751.9 daltons and carries a net positive charge at physiological pH because of its arginine residue. It dissolves freely in water and in common aqueous buffers, and typically appears as a white or off-white lyophilized powder. The amide backbone makes the molecule susceptible to peptidases, which limits oral use and favors intranasal or parenteral routes. Nomenclature in the literature varies: the substance is also described by the sequence abbreviation TP-7 and by a Russian trade designation.

Related pages on this site

Selank Background and Peptide Chemistry

Reported pharmacological effects center on reduced anxiety-like behavior in animal models and on measures of memory and learning. Proposed contributing mechanisms include modulation of GABAergic signaling, shifts in monoamine turnover, and changes in the activity of enzymes that degrade neuropeptides. Effects on the expression of genes linked to neuroplasticity have also been described. No single molecular target is widely accepted, and whether the behavioral findings arise from one pathway or several remains an open question.

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.

Origins and Proposed Mechanisms

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.

Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences as a structural analogue of tuftsin, a naturally occurring tetrapeptide fragment of the immunoglobulin heavy chain. The added Pro-Gly-Pro tail was intended to slow enzymatic degradation and extend biological activity. In Russia it is registered as an anxiolytic nasal preparation, while regulators elsewhere have not approved it for clinical use.

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.

Supporting material

=== Chemicals === E-cigarette components include a mouthpiece, a cartridge (liquid storage area), a heating element or atomizer, a microprocessor, a battery, and some of them have a LED light at the tip. They are disposable or reusable devices. Disposable ones are not rechargeable and typically cannot be refilled with a liquid. There is a diverse range of disposable and reusable devices, resulting in broad variations in their structure and their performance. Since many devices include interchangeable components, users have the ability to alter the nature of the inhaled vapor. For the majority of e-cigarettes, many aspects are similar to their traditional counterparts, such as giving nicotine to the user. The use of an e-cigarette simulates the action of smoking, with a vapor that somewhat resembles cigarette smoke. E-cigarettes do not involve tobacco combustion, and they do not produce vapor between puffs. They do not produce sidestream smoke or sidestream vapor. Vapor production basically entails preprocessing, vapor generation, and postprocessing. First, the e-cigarette is activated by pressing a button, or other devices switch on by an airflow sensor or other type of trigger sensor. Then, power is released to an LED, other sensors, and other parts of the device, and to a heating element or other kind of vapor generator. Subsequently, the e-liquid flows by capillary action to the heating element or other devices to the e-cigarette vapor generator. Second, the e-cigarette vapor processing entails vapor generation.

==== Myosin storage myopathy ==== In myosin storage myopathies, myosin accumulates beneath sarcolemma and between myofibrils, forming protein aggregates. A myopathy associated with the gene MYH7 is autosomal dominant myosin storage congenital myopathy-7A (CMYP7A).

March 14: A decree provides that Chambers of Commerce and Consultative Chambers of Arts and Manufacturing include women among both voters and eligible candidates. April 3: Law modifying Articles 334 and 335 of the Penal Code and Articles 5 and 7 of the Code of Criminal Procedure; notably amends provisions relating to pimping, the corruption of minors, incitement to debauchery, corruption of youth, and international trafficking. December 15, 1904: Abolition of the ban on marrying the "accomplice in adultery." February 7, 1905: Decree implementing the international agreement aimed at effectively protecting against the criminal trade known as "white slavery" (international agreement from May 1904). 1907

Werner discovered the spatial arrangements of the ligands that were involved in the formation of the complex hexacoordinate cobalt. His theory allows one to understand the difference between a coordinated ligand and a charge balancing ion in a compound, for example the chloride ion in the cobaltammine chlorides and to explain many of the previously inexplicable isomers. In 1911, Werner first resolved the cobalt/ammonia coordination complex hexol into optical isomers, overthrowing the theory that only carbon compounds could possess chirality.

=== Environmental contaminants === Since American kestrels are carnivores, toxic chemical runoff ingested by their prey can concentrate at high levels in their blood. Wild kestrels are subject to immunomodulation, or an altered immune response, to polybrominated diphenyl ethers (PBDEs), a group of industrial flame retardants that may leach from factories into the environment. When PBDEs accumulate in body tissues of kestrels, the T-cell mediated immune response decreases in efficiency. As a result, kestrels that ingest PBDEs may not respond sufficiently to viruses or other invading microorganisms. In addition, certain PBDEs may suppress the growth and development of the spleen and bursa in American kestrels. While PBDEs can affect immune response and suppress growth of certain organs, they can also affect the thyroid system of American Kestrels. Exposure to PBDEs in vivo can alter the thyroid system and retinol concentrations in kestrels. This leads to oxidative stress, lipid peroxidation, and changes in glutathione metabolism. These systems are important in early development, growth, regulation of metabolism, thermoregulation, and reproduction. Oxidative stress is also known to contribute to cancers and neurological diseases. Exposure to polychlorinated biphenyls (PCBs) might also affect American Kestrel reproduction. It was found that PCBs affect the function of carotenoids in kestrels. This led to changes in coloration, especially during breeding season for adults. PCB-exposed males where duller and contributed less to egg incubation than unexposed males.

Sources: en.wikipedia.org

Supporting material

=== Restructuring and acquisition by Embracer Group (2015–2024) === Gearbox established Gearbox Publishing in 2015, first announced to the public in December 2016, as to publish third-party games, starting with the remastered version of Bulletstorm from People Can Fly. Pitchford said that it wanted to start expanding into other areas of capital growth beyond games that Gearbox was traditionally known for, and planned to use Gearbox Publishing as a starting point. Later, in May 2019, Gearbox established The Gearbox Entertainment Company, Inc. (Gearbox Entertainment) as a parent company for both Gearbox Software and Gearbox Publishing. Co-founder Landon Montgomery, who had left the company around 2007, died on March 25, 2020. In April 2021, Gearbox Entertainment was wholly acquired by the Embracer Group for precisely $363 million rising to $1.378 billion should it reach specific operational targets. This addition would be the company's seventh major publishing group. Pitchford stated that while it was looking to raise capital from 2016, it came to meet with Embracer, and saw that its decentralized studio model would work well for Gearbox. 2K remained on Gearbox's board and continued to publish the Borderlands series. Gearbox Entertainment opened a second Canadian studio, Gearbox Studio Montreal, in August 2021, to support 250 new staff, bringing the total size of Gearbox to around 850 employees.

When binding to the signaling molecule, the receptor protein changes in some way and starts the process of transduction, which can occur in a single step or as a series of changes in a sequence of different molecules (called a signal transduction pathway). The molecules that compose these pathways are known as relay molecules. The multistep process of the transduction stage is often composed of the activation of proteins by addition or removal of phosphate groups or even the release of other small molecules or ions that can act as messengers. The amplification of a signal is one of the benefits to this multiple step sequence. Other benefits include more opportunities for regulation than simpler systems do and the fine-tuning of the response, in both unicellular and multicellular organisms. In some cases, receptor activation caused by ligand binding to a receptor is directly coupled to the cell's response to the ligand. For example, the neurotransmitter GABA can activate a cell surface receptor that is part of an ion channel. GABA binding to a GABAA receptor on a neuron opens a chloride-selective ion channel that is part of the receptor. GABAA receptor activation allows negatively charged chloride ions to move into the neuron, which inhibits the ability of the neuron to produce action potentials. However, for many cell surface receptors, ligand-receptor interactions are not directly linked to the cell's response.

Unlike folinic acid, it may be used in MTFHR deficiency and MTHFS deficiency: 5-MTHF is the directly usable form of folate in methoinine metabolism, in contrast to folinic acid which needs to be converted to 5-MTHF by these enzymes. Secondary CFD could be treated by non-folate drugs, depending on the precise cause. For example, serine deficiency can be helped by direct supplementation of serine and glycine: this helps with seizure control but does little for psychomotor development. Folic acid (FA), the oxidized form commonly found in diet and ordinary supplements, is not suitable for most forms of CFD and may worsen it. "Transport of folate compounds from the intestine to the brain and competitive inhibition of 5-MTHF transport by FA. Conversion of FA to 5-MTHF is limited in the intestine and is mainly handled by DHFR in the liver, although its enzymatic activity is low in humans. In contrast, folinic acid is efficiently metabolized to 5-MTHF in the intestine and liver. When an excess amount of FA is taken, it cannot be fully reduced by DHFR in the liver and unmetabolized FA appears in the plasma. Because FA has higher affinity to FR1 expressed at the choroid plexus than 5-MTHF, it can act as a competitive inhibitor against 5-MTHF transport from the plasma to the CSF. In addition, FA cannot be metabolized to 5-MTHF efficiently in the brain with extremely low DHFR activity. Thus, excess FA intake may lead to a less effective supply of 5-MTHF to the brain compared with that of folinic acid supplementation."

== Diagnosis == No specific test exists to diagnose polymyalgia rheumatica; many other diseases can cause inflammation and pain in muscles, but a few tests can help narrow down the cause of the pain. Limitation in shoulder motion or swelling of the joints in the wrists or hands, are noted by the doctor. One blood test usually performed is the erythrocyte sedimentation rate (ESR) which measures how fast the patient's red blood cells settle in a test tube. The faster the red blood cells settle, the higher the ESR value (measured in mm/hour), which suggests that inflammation may be present. Many conditions can cause an elevated ESR, so this test alone is not proof that a person has polymyalgia rheumatica. Another test that checks the level of C-reactive protein (CRP) in the blood may also be conducted. CRP is produced by the liver in response to an injury or infection, and people with polymyalgia rheumatica usually have high levels. However, like the ESR, this test is also not very specific. Polymyalgia rheumatica is sometimes associated with temporal arteritis, a condition requiring more aggressive therapy. To test for this additional disorder, a biopsy sample may be taken from the temporal artery.

A countercurrent multiplication loop is a system where fluid flows in a loop so that the entrance and exit are at similar low concentration of a dissolved substance but at the far end of the loop there is a high concentration of that substance. A buffer liquid between the incoming and outgoing tubes receives the concentrated substance. The incoming and outgoing tubes do not touch each other. The system allows the buildup of a high concentration gradually, by allowing a natural buildup of concentration towards the tip inside the in-going tube, (for example using osmosis of water out of the input pipe and into the buffer fluid), and the use of many active transport pumps each pumping only against a very small gradient, during the exit from the loop, returning the concentration inside the output pipe to its original concentration. The incoming flow starting at a low concentration has a semipermeable membrane with water passing to the buffer liquid via osmosis at a small gradient. There is a gradual buildup of concentration inside the loop until the loop tip where it reaches its maximum. Theoretically a similar system could exist or be constructed for heat exchange. In the example shown in the image, water enters at 299 mg/L (NaCl / H2O). Water passes because of a small osmotic pressure to the buffer liquid in this example at 300 mg/L (NaCl / H2O). Further up the loop there is a continued flow of water out of the tube and into the buffer, gradually raising the concentration of NaCl in the tube until it reaches 1199 mg/L at the tip.

Sources: en.wikipedia.org

Supporting material

Blumofe (1930), producer of Bound for Glory, nominated for the Academy Award for Best Picture Ben Maddow (1930), screenwriter for The Asphalt Jungle, God's Little Acre and The Mephisto Waltz Albert Maltz (1930), screenwriter for Destination Tokyo and one of the Hollywood Ten Arnold M. Auerbach (1932), Primetime Emmy Award-winning American comedy writer William Ludwig (1932), Academy Award-winning screenwriter, Interrupted Melody Martin Manulis (1935), CBS television and movie producer, Days of Wine and Roses, The Best of Broadway, Climax!, Suspense; creator of Playhouse 90; former president of 20th Century Fox Television Charles H. Schneer (1940), film producer known for his collaboration with Ray Harryhausen I.A.L. Diamond (1941), screenwriting partner of Billy Wilder; co-author of Some Like It Hot; co-winner of the Academy Award for Best Original Screenplay for The Apartment Don M.

=== Oak Park River Forest High School Outbreak === After 17 new cases were diagnosed in one week, the Oak Park Health Department forced Oak Park River Forest High School to cancel all extracurricular activities on December 3, 2021 and hinted toward a future move to suspend in-person learning. Oak Park Public Health Director Dr. Theresa Chapple expressed concerns that "only about 100 to 200 students" were tested each week which left the department blind to the actual size of the outbreak. SHIELD Illinois was engaged by the district on Saturday, December 4 about the possibility of testing the entire school population in one day. SHIELD rallied every employee trained to collect specimens, including executive leadership, accounting specialists, and logistics team members. Monday, December 6, 2021, SHIELD Illinois collected specimens from 1,651 students, faculty, and staff. This initial round of testing identified 20 positive patients. The health department allowed extracurricular activities to resume on December 7, 2021. SHIELD Illinois repeated the same process on December 9. This time testing 1,396 faculty, staff, and students--identifying an additional 3 positive cases.

=== Medical === Pentazocine is used primarily to treat pain, although its analgesic effects are subject to a ceiling effect. It has been discontinued by its corporate sponsor in Australia, although it may be available through the special access scheme.

=== Mechanisms === The mechanisms underlying most herb-drug interactions are not fully understood. Interactions between herbal medicines and anticancer drugs typically involve enzymes that metabolize cytochrome P450. For example, St. John's Wort has been shown to induce CYP3A4 and P-glycoprotein in vitro and in vivo.

July 20 Blue Origin NS-16: On the 52nd anniversary of the Apollo 11 Moon landing, Jeff Bezos successfully launches the Blue Origin rocket New Shepard 4 in Van Horn, Texas, carrying himself, his brother Mark, 82-year-old retired pilot Wally Funk, and 18-year-old college student Oliver Daemen. The rocket lands back on Earth within minutes, completing the first crewed spaceflight with reusable rockets. Tom Barrack, founder of Colony Capital and an advisor of Donald Trump, is indicted for making false statements to the FBI and being an unregistered agent for the United Arab Emirates. He is found not guilty in 2022. The Milwaukee Bucks defeat the Phoenix Suns (4–2) in the 2021 NBA Finals to win their first championship since 1971. July 21 The 2021 NHL expansion draft is held at Gas Works Park in Seattle, where the 32nd NHL team, the Seattle Kraken fills out its first ever roster of players. Santa Monica based video game publisher Activision Blizzard, Inc. is hit with a massive lawsuit from the California Department of Fair Employment and Housing after a two-year investigation reveals a "frat boy" like work environment where female employees face sexual harassment, discrimination, and retaliation for speaking out against the company. The Tennessee State Building Commission announces that the statue of Nathan Bedford Forrest will be moved from the Tennessee State Capitol to the Tennessee State Museum. The Missouri Supreme Court unanimously upholds a 2020 amendment to the state's constitution that expanded Medicaid eligibility.

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 mechanisms are proposed for Selank?

Reports describe effects on GABA-A receptor expression, monoamine turnover, and neurotrophic factor levels. These are proposed mechanisms drawn mainly from animal models. No single molecular target has been established.

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