If you have been reading about selank and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2026-04-24. 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.
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 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.
| 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 |
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.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, frequently abbreviated as TKPRPGP. It was designed as a structural analogue of tuftsin, a naturally occurring tetrapeptide released by enzymatic cleavage of the immunoglobulin heavy chain. The two additional proline residues at the C-terminal end extend the parent chain and change how the molecule behaves in solution. The free peptide has a calculated molecular mass of approximately 751.9 g/mol and is generally supplied as a lyophilised white to off-white powder.
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.
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.
The esophagus has four points of constriction. When a corrosive substance, or a solid object is swallowed, it is most likely to lodge and damage one of these four points. These constrictions arise from particular structures that compress the esophagus. These constrictions are:
A sarcomere is defined as the segment between two neighbouring Z-lines (or Z-discs). In electron micrographs of cross-striated muscle, the Z-line (from the German "zwischen" meaning between) appears in between the I-bands as a dark line that anchors the actin myofilaments. Surrounding the Z-line is the region of the I-band (for isotropic). I-band is the zone of thin filaments that is not superimposed by thick filaments (myosin). Following the I-band is the A-band (for anisotropic). Named for their properties under a polarized light microscope. An A-band contains the entire length of a single thick filament. The anisotropic band contains both thick and thin filaments. Within the A-band is a paler region called the H-zone (from the German "heller", brighter). Named for their lighter appearance under a polarization microscope. H-band is the zone of the thick filaments that has no actin. Within the H-zone is a thin M-line (from the German "mittel" meaning middle), appears in the middle of the sarcomere formed of cross-connecting elements of the cytoskeleton.
==== Martyrs ==== The decision as to whether martyrs had died for their faith in Christ and the consequent permission of veneration lay originally with the bishop of the place in which they had borne their testimony. The bishop inquired into the motive of the person's death and, on finding they had died a martyr, sent their name with an account of their martyrdom to other churches, especially neighboring ones, so that, in the event of approval by their respective bishops, the cultus of the martyr might extend to their churches also and that the faithful, as is said of Ignatius of Antioch in the "Acts" of his martyrdom "might hold communion with the generous martyr of Christ" (generoso Christi martyri communicarent). Martyrs whose cause, so to speak, had been discussed, and the fame of whose martyrdom had been confirmed, were known as proved (vindicati) martyrs. That word probably did not antedate the fourth century, when it was introduced into the Church at Carthage; but the fact is certainly older. In the earlier ages, therefore, this veneration was entirely local and passed from one church to another with the permission of their bishops. This is clear from the fact that in ancient Christian cemeteries there are found paintings of only those martyrs who had suffered in that neighborhood. It explains, also, the almost universal veneration very quickly paid to, e.g., Lawrence, Cyprian, and Sixtus II, who were killed by the Roman Emperor Valerian.
Glucose-6-phosphate dehydrogenase deficiency (G6PDD), also known as favism, is the most common enzyme deficiency anemia worldwide. It is an inborn error of metabolism that predisposes to red blood cell breakdown. Most of the time, those who are affected have no symptoms. Following a specific trigger, symptoms such as yellowish skin, dark urine, shortness of breath, and feeling tired may develop. Complications can include anemia and newborn jaundice. Some people never have symptoms. It is an X-linked recessive disorder that results in defective glucose-6-phosphate dehydrogenase enzyme. Glucose-6-phosphate dehydrogenase is an enzyme that protects red blood cells, which carry oxygen from the lungs to tissues throughout the body, from reactive oxygen species. An enzyme defect results in the premature breakdown of red blood cells. This destruction of red blood cells is called hemolysis. Red blood cell breakdown may be triggered by infections, certain medication, stress, or foods such as fava beans. Depending on the specific mutation the severity of the condition may vary. Diagnosis is based on symptoms and supported by blood tests and genetic testing. Affected persons must avoid dietary triggers, notably fava beans. This can be difficult, as fava beans may be called "broad beans" and are used in many foods, whole or as flour. Falafel is probably the best known, but fava beans are often used as filler in meatballs and other foods. Treatment of acute episodes may include medications for infection, stopping the offending medication, or blood transfusions.
In 2004, John L. Helgerson, the Inspector General of the Central Intelligence Agency (CIA), conducted an internal review of the agency's pre-9/11 performance and was harshly critical of senior CIA officials for not doing everything possible to confront terrorism. According to Philip Giraldi in The American Conservative, Helgerson criticized their failure to stop two of the 9/11 hijackers, Nawaf al-Hazmi and Khalid al-Mihdhar, as they entered the United States and their failure to share information on the two men with the FBI. In May 2007, senators from both major U.S. political parties (the Republican and Democratic parties) drafted legislation to make the review public. One of the backers, Senator Ron Wyden said, "The American people have a right to know what the Central Intelligence Agency was doing in those critical months before 9/11." The report was released in 2009 by President Barack Obama.
Sources: en.wikipedia.org
An indicative cost structure for a fine chemical company is shown in Table 10. Nowadays, a full 7-day/week operation, consisting of four or five shift teams, each working 8h per day, has become the standard. In terms of production costs, this is the most advantageous scheme. Higher salaries for night work are more than offset by better fixed cost absorption. As part of the budgeting process, standard costs for a production campaign of a particular fine chemical are determined on the basis of past experience. The actual results of the campaign are then compared with the standard. The capability of a fine chemical company to make dependable manufacturing cost forecasts is a distinct competitive advantage.
== Pharmacology == Although it was marketed as being safer, meprobamate has most of the pharmacological effects and dangers of barbiturates and acts at the barbiturate binding site (though it is less sedating at effective doses). It is reported to have some anticonvulsant properties against absence seizures, but can exacerbate generalized tonic–clonic seizures. Meprobamate's mechanism of action is not completely known. It has been shown in animal studies to have effects at multiple sites in the central nervous system, including the thalamus and limbic system. Meprobamate binds to GABAA receptors which interrupts neuronal communication in the reticular formation and spinal cord, causing sedation and altered perception of pain. Meprobamate has the ability to activate currents even in the absence of GABA. This relatively unique property makes meprobamate exceptionally dangerous when used in combination with other GABA-mediated drugs (including alcohol). It is also a potent adenosine reuptake inhibitor. Related drugs include carisoprodol and tybamate (prodrugs of meprobamate), phenprobamate, felbamate, mebutamate, and methocarbamol.
Participants were randomized (1:1) to receive neoadjuvant pembrolizumab and enfortumab vedotin followed by surgery followed by adjuvant enfortumab vedotin in combination with pembrolizumab followed by pembrolizumab as a single agent or to undergo immediate surgery alone.
The ceasefire followed weeks of escalating violence between Israel and Hezbollah forces in Lebanon, which intensified in March 2026 after regional tensions linked to the Iran war. Israeli airstrikes and ground operations across Lebanon, combined with Hezbollah's rocket and drone attacks toward northern Israel, resulted in heavy casualties and widespread displacement. By mid-April, more than 2,000 people had been killed in Lebanon, and over one million had been displaced. Prior ceasefire arrangements related to the Iran war did not formally include Lebanon, contributing to continued hostilities and complicating diplomatic efforts. The Israel–Lebanon peace talks opened between Israel and Lebanon during 2026, following the renewed fighting between Israel and Hezbollah. For the first time since the failure of the May 17 Agreement (1983), Israel and the Lebanese government announced the opening of direct negotiations with the goal of reaching a peace agreement and disarming Hezbollah.
== Taxonomy and distribution == Within the world of taxonomy, the stable 'Classical System' of Michaelsen (1900) and Stephenson (1930) was gradually eroded by the controversy over how to classify earthworms, such that Fender and McKey-Fender (1990) went so far as to say, "The family-level classification of the megascolecid earthworms is in chaos." Over the years, many scientists have developed their own classification systems for earthworms, which led to confusion, and these systems have been and still continue to be revised and updated. The classification system used here which was developed by Blakemore (2000), is a modern reversion to the Classical System that is historically proven and widely accepted. Categorization of a megadrile earthworm into one of its taxonomic families under suborders Lumbricina and Moniligastrida is based on such features as the makeup of the clitellum, the location and disposition of the sex features (pores, prostatic glands, etc.), number of gizzards, and body shape. Currently, over than 6,000 species of terrestrial earthworms are named, as provided in a species name database, but the number of synonyms is unknown. The families, with their known distributions or origins:
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.
Intranasal administration predominates in both animal and human research because it avoids hepatic first-pass metabolism. Injectable and intraperitoneal routes appear in animal work mainly for comparison.