nootropic comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2026-03-20. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C33H57N11O9 | Derived from the seven-residue sequence |
| Molecular weight | About 751.9 g/mol | Average mass; the monoisotopic value is slightly lower |
| Residue count | Seven amino acids | Thr-Lys-Pro-Arg-Pro-Gly-Pro |
| Parent compound | Tuftsin (Thr-Lys-Pro-Arg) | Selank extends tuftsin at the C-terminus |
| Compound class | Synthetic short peptide | Studied in a research setting; not a licensed drug in most markets |
Selank is studied chiefly as an animal-model anxiolytic with proposed secondary effects on memory and immune signaling. Reported mechanisms include modulation of the GABA-A receptor complex, inhibition of enkephalin-degrading enzymes, and shifts in monoamine turnover within limbic structures. Some experiments describe increased expression of brain-derived neurotrophic factor in the hippocampus after repeated dosing. No single molecular target has been confirmed, and the peptide does not bind any receptor with the selectivity typical of a conventional small-molecule drug. Mechanism therefore remains a set of hypotheses rather than an established pathway.
Laboratory work relies on standard behavioral paradigms. Rodents are tested in the elevated plus maze, open field, and passive avoidance tasks, with outcomes compared against diazepam or vehicle controls. Intranasal dosing is used most often because it bypasses first-pass metabolism, though intraperitoneal and intravenous routes also appear in published protocols. Biochemical endpoints include tissue BDNF concentrations, cytokine levels, and monoamine metabolites. Human data are limited to small Russian trials reporting reduced anxiety scores; most were not prospectively registered, and few employed independent outcome assessment.
Measuring peptide exposure inside the brain is technically difficult. Selank is degraded rapidly in plasma, and assays must separate intact peptide from fragments, which favors targeted mass spectrometry over immunoassays alone. Reported half-lives are short, on the order of minutes, so effects observed hours later are attributed to downstream signaling rather than to the parent compound. Blood-brain barrier permeability is debated and rarely quantified directly. Gaps include absent dose-response characterization, inconsistent reporting of purity, and almost no pharmacokinetic data from human participants.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. Its four N-terminal residues reproduce tuftsin, a tetrapeptide fragment of the immunoglobulin heavy chain, while the C-terminal Pro-Gly-Pro extension is a synthetic addition. The peptide has a molecular mass near 752 daltons and carries a net positive charge at physiological pH because of the arginine and lysine side chains. Published indexes list it under the name Selank and the sequence abbreviation TKPRPGP. Solid-phase peptide synthesis is the standard production route for research quantities.
Development took place at the Institute of Molecular Genetics of the Russian Academy of Sciences, where a series of short peptides were designed in the 1980s and 1990s. Selank was selected from variants of tuftsin that showed resistance to plasma peptidases. Russian regulatory approval covers it as an anxiolytic agent given intranasally. Outside that market the compound is normally handled as a research chemical rather than a medicine, and no widely recognised international pharmacopoeial monograph exists. The name Selank is a coined trade designation rather than a systematic chemical name.
Development work on the compound began in the 1980s and 1990s at the Institute of Molecular Genetics in Moscow, within the same research programme that produced the peptide Semax. Early investigators sought a tuftsin derivative with improved resistance to enzymatic breakdown and with activity in the central nervous system after peripheral administration. Most of the primary literature from this period was published in Russian, a factor that still shapes how easily the findings can be checked by outside groups.
Naming for this compound is not fully standardised in English sources. The spelling Selanc appears in some transliterations, and catalogue entries may instead list the peptide sequence itself as the identifier. Reference material sometimes groups it with other short synthetic peptides studied for behavioural effects, which can create confusion when citations are compared. Distinguishing the exact sequence from related tuftsin analogues is therefore a practical first step when reviewing any dataset or specification sheet.
Quality assessment of Selank samples typically combines purity determination with identity confirmation and counter-ion analysis. Purity is usually reported as a percentage by chromatographic area, with values above 95 percent often quoted for research-grade material. Water content and residual solvents are checked in lyophilized batches because they affect both stability and accurate mass determination. A reported purity figure does not by itself establish that a sample is the intended sequence, so orthogonal methods are needed to rule out sequence isomers or truncation products.
Characterization of Selank in laboratory settings relies on standard peptide analytical techniques. Reverse-phase high-performance liquid chromatography separates the peptide from related impurities and degradation products, while mass spectrometry confirms molecular identity through accurate mass measurement. Amino acid analysis and peptide sequencing verify the primary structure when reference material is unavailable. Because Selank is a short chain, fragmentation-based analysis produces a diagnostic ion pattern that supports confident identification.
Peptide stability depends strongly on temperature, moisture, and pH. Lyophilized Selank is generally most stable when stored cold and dry, with freezer temperatures commonly used for long-term storage. In solution, the compound is susceptible to hydrolysis and to microbial growth if it is not handled aseptically. The C-terminal proline-rich extension appears to slow enzymatic cleavage relative to tuftsin, though quantitative degradation rates vary with the matrix and the conditions tested. Published stability data specific to Selank remain sparse.
Moscow is one of the largest centers for science in Russia. The headquarters of the Russian Academy of Sciences are located in the city, as well as research and applied science institutions. Moscow also contains the following institutions:
== Efficacy == As of 2021, many thousands of papers had been published on the efficacy of acupuncture for the treatment of various adult health conditions, but there was no robust evidence it was beneficial for anything, except shoulder pain and fibromyalgia. The evidence for its efficacy in shoulder pain is low quality and includes only two studies. Its efficacy for fibromyalgia does not appear to be clinically significant. For Science-Based Medicine, Steven Novella wrote that the overall pattern of evidence was reminiscent of that for homeopathy, compatible with the hypothesis that most, if not all, benefits were due to the placebo effect, and strongly suggestive that acupuncture had no beneficial therapeutic effects at all. Harriet Hall noticed that according to Edzard Ernst in 2011, systematic reviews agreed that acupuncture works for neck pain, but not for every other pain—and that makes its whole enterprise suspicious. A 2024 review concluded that it is no more effective than sham acupuncture for neck pain reduction.
== Causes == Leptomeningeal carcinomatosis occurs when the cancer cells invade the cerebrospinal fluid and spread throughout the central nervous system. The metastatic tumor cells grow either attached to the pia mater covering the brain and spinal cord or floating unattached to the subarachnoid space. Tumors of diverse origins and hematologic cancers may spread to this space. Some patients may develop leptomeningeal cancer while receiving chemotherapy for their primary tumour, partly because the blood-brain barrier serves as a protective filter that shields the central nervous system from toxins and pathogens circulating in the blood. While essential for protection, this barrier also complicates treatment, as many chemotherapy agents and biopharmaceuticals struggle to cross into the brain and spinal cord.
Sources: en.wikipedia.org
As of January 2026, there were 575 federally recognized tribes. There are approximately 326 Indian reservations. The tribes hold a government-to-government relationship with the U.S. federal government in Washington and are legally defined as domestic dependent nations with inherent tribal sovereignty rights. In addition to the five major territories, the U.S. also asserts sovereignty over the United States Minor Outlying Islands in the Pacific Ocean and the Caribbean. The seven undisputed islands without permanent populations are Baker Island, Howland Island, Jarvis Island, Johnston Atoll, Kingman Reef, Midway Atoll, and Palmyra Atoll. U.S. sovereignty over the unpopulated Bajo Nuevo Bank, Navassa Island, Serranilla Bank, and Wake Island is disputed.
The concept of health technology assessment (HTA) was first coined in 1967 by the U.S. Congress in response to the increasing need to address the unintended and potential consequences of health technology, along with its prominent role in society. It was further institutionalized with the establishment of the congressional Office of Technology Assessment (OTA) in 1972–1973. HTA is defined as a comprehensive form of policy research that examines short- and long-term consequences of the application of technology, including benefits, costs, and risks. Due to the broad scope of technology assessment, it requires the participation of individuals besides scientists and health care practitioners such as managers and even the consumers. Several American organizations provide health technology assessments and these include the Centers for Medicare and Medicaid Services (CMS) and the Veterans Administration through its VA Technology Assessment Program (VATAP). The models adopted by these institutions vary, although they focus on whether a medical technology being offered is therapeutically relevant. A study conducted in 2007 noted that the assessments still did not use formal economic analyses. Aside from its development, however, assessment in the health technology industry has been viewed as sporadic and fragmented Issues such as the determination of products that needed to be developed, cost, and access, among others, also emerged.
High efficiency and throughput Increased simplicity and speed The reaction can be driven to completion and high yields through the use of excess reagent. In this method, building blocks are protected at all reactive functional groups. The order of functional group reactions can be controlled by the order of deprotection. This method is used for the synthesis of peptides, deoxyribonucleic acid (DNA), ribonucleic acid (RNA), and other molecules that need to be synthesised in a certain alignment. More recently, this method has also been used in combinatorial chemistry and other synthetic applications. The process was originally developed in the 1950s and 1960s by Robert Bruce Merrifield in order to synthesise peptide chains, and which was the basis for his 1984 Nobel Prize in Chemistry. In the basic method of solid-phase synthesis, building blocks that have two functional groups are used. One of the functional groups of the building block is usually protected by a protective group. The starting material is a bead which binds to the building block. At first, this bead is added into the solution of the protected building block and stirred. After the reaction between the bead and the protected building block is completed, the solution is removed and the bead is washed. Then the protecting group is removed and the above steps are repeated. After all steps are finished, the synthesised compound is chemically cleaved from the bead.
Sources: en.wikipedia.org
== See also == Anti-Chilean sentiment Chile–Peru relations Chilenization of Tacna, Arica, and Tarapacá Colombianization of Leticia, Putumayo and Caquetá Ecuadorian–Peruvian territorial dispute Indigenous peoples and the War of the Pacific
=== Mechanical debridement === When removal of tissue is necessary for the treatment of wounds, hydrotherapy which performs selective mechanical debridement can be used. Examples of this include directed wound irrigation and therapeutic irrigation with suction. Baths with whirlpool water flow should not be used to manage wounds because a whirlpool will not selectively target the tissue to be removed and can damage all tissue. Whirlpools also create an unwanted risk of bacterial infection, can damage fragile body tissue, and in the case of treating arms and legs, bring risk of complications from edema. Hydrosurgery uses a high‐pressure, water‐based jet system to remove burnt skin. This should leave behind the unburned, healthy skin. A 2019 Cochrane systematic review aimed to find out if burns treated with hydrosurgery heal more quickly and with fewer infections than burns treated with a knife. The review authors only found one randomised controlled trial (RCT) with very low certainty evidence that investigated this. Based on this trial, they concluded that it is uncertain whether or not hydrosurgery is better than conventional surgery for early treatment of mid‐depth burns. More RCTs are needed to fully answer this question. Allowing a dressing to proceed from moist to dry, then manually removing the dressing causes a form of non-selective debridement. This method works best on wounds with moderate amounts of necrotic debris (e.g. "dead tissue").
Livestock farming is one of the top contributors to deforestation, land degradation, water pollution and desertification. Among other reasons, this has led to the new promising technology of meat bioprinting. One alternative to livestock farming is cultured meat, also known as lab-grown meat. Cultured meat is produced by taking a small biopsy from animals, extracting the myosatellite cells and adding growth serum to multiply the cells. The resulting product is then used as a material for bioprinting meat. The post-processing phase, among other steps, includes adding flavour, vitamins and iron to the product. Yet another alternative is printing a meat analogue. Novameat, a Spanish startup has been able to print a plant-based steak and mimic the texture and appearance of real meat. In 2023, Austrian food tech company Revo Foods launched a 3D printed salmon filet alternative based on mycoprotein in Supermarkets of German REWE Group, which became the first 3D printed meat/seafood alternative available in supermarkets worldwide, marking an important milestone towards increased availability of 3D printed food items.
Sources: en.wikipedia.org
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.
Tuftsin contains four residues, while selank carries an additional Pro-Gly-Pro segment at the carboxyl end. That extension is intended to reduce enzymatic cleavage. Comparative pharmacokinetic data in humans remain limited.
No single receptor target is widely accepted as the definitive mediator of the reported effects. Proposed contributors include GABAergic modulation, shifts in monoamine turnover, and altered neuropeptide degradation. The mechanism is treated in the literature as unresolved.
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.