Selank raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2025-09-25. Anything still debated is marked as such rather than presented as settled.
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.
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.
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 |
|---|---|---|
| Route studied | Intranasal | Predominant route in published reports |
| Circulation stability | Short, minutes scale | Peptidases cleave it; the tail slows the process |
| Analytical method | RP-HPLC with mass spectrometry | Used for identity and purity assessment |
| Reported outcome domains | Anxiety and cognitive measures | Derived from small, mostly regional trials |
| Regulatory status | Marketed in Russia | Availability outside that market is limited |
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.
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.
Published clinical work is concentrated in Russian-language journals and generally involves small samples without independent replication. Systematic reviews in English note the shortage of randomised, placebo-controlled trials and the difficulty of verifying methods from translated reports. Outcome measures vary between studies, which complicates pooling of results. Interest in the compound as a cognitive or anxiolytic agent therefore rests on a thinner evidence base than the volume of citations suggests. Replication in well-powered trials with preregistered endpoints would be needed before firm conclusions about efficacy can be drawn.
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.
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.
80. Coll Antropol. 2005 Jun;29(1):321-5. Gastric pentadecapeptide BPC 157 promotes corneal epithelial defects healing in rats. Lazić R(1), Gabrić N, Dekaris I, Bosnar D, Boban-Blagaić A, Sikirić P. Author information: (1)Eye Clinic, Svjetlost, Zagreb, Croatia. ratimir.lazic@zg.htnet.hr We evaluated the role of human gastric pentadecapeptide BPC 157 in corneal epithelial defects healing in rats. 48 rats, in 4 groups (N=12). Total debridement of corneal epithelium preformed unilaterally and lesions stained and photographed. Animals medicated as follows: distilled water (control group) or BPC 157 2 pg/ml, 2 ng/ml, 2 microg/ml, 2 drops/rat eye started immediately after injury induction, every 8 hours up to 40 hours (i.e., at 0, 8, 16, 24, 32, 40 h). Lesions were photographed before application or sacrifice (at 48 h). Defect area was analyzed using a special program. Through 48 hour period a steady recovery is noted in controls. Recovery was markedly accelerated in eyes on microg- or ng-topical regimen of BPC 157 (p < 0.05). Of note, unlike control lesion present also after 48 h, these lesions disappeared already following 40 h (microg) or 48 h (ng) post-injury. BPC 157 was shown to be effective in promoting corneal defects healing in rats. Results were dose dependent.
39. Pain Physician. 2026 Sep;29(6):E753-E754. In Response to Comment on "Cervical Erector Spinae Plane Block vs. Epidural Steroid Injection for Cervical Radicular Pain: A Clinical Trial". Salehi S(1)(2). Author information: (1)Iran University of Medical Sciences, Tehran, Iran. (2)Department of Anesthesiology and Pain Medicine, Baqiyatallah University of Medical Sciences, Tehran, Iran.
In Indonesia, the National Transportation Safety Committee (NTSC; Indonesian: Komite Nasional Keselamatan Transportasi, KNKT) is responsible for the investigation of incidents and accidents, including air accidents. Its aim is the improvement of transportation safety, not just aviation, in Indonesia. Created in 1999 in Italy, the Agenzia Nazionale per la Sicurezza del Volo (ANSV), has two main tasks: conducting technical investigations for civil aviation aircraft accidents and incidents, while issuing safety recommendations as appropriate; and conducting studies and surveys aimed at increasing flight safety. The organization is also responsible for establishing and maintaining the "voluntary reporting system". Although not under the supervision of the Ministry of Infrastructure and Transport, the ANSV is a public authority under the oversight of the Presidency of the Council of Ministers of Italy.
Glycogenolysis and gluconeogenesis in liver. Glycogenolysis and lactate release in skeletal muscle. Contract sphincters of Gastrointestinal tract. Thickened secretions from salivary glands. Insulin and glucagon secretion from pancreas. Inhibit histamine-release from mast cells. Increase protein content of secretions from lacrimal glands. Receptor also present in cerebellum. Bronchiole dilation (targeted while treating asthma attacks) Involved in brain - immune - communication Short-acting β2 agonists (SABA) bitolterol fenoterol hexoprenaline isoprenaline (INN) or isoproterenol (USAN) levosalbutamol (INN) or levalbuterol (USAN) orciprenaline (INN) or metaproterenol (USAN) pirbuterol procaterol salbutamol (INN) or albuterol (USAN) terbutaline Long-acting β2 agonists (LABA) arformoterol (some consider it to be an ultra-LABA) bambuterol clenbuterol formoterol salmeterol Ultra-long-acting β2 agonists (ultra-LABA) carmoterol indacaterol milveterol (GSK 159797) olodaterol vilanterol (GSK 642444)
Can resolve fine-scale variations in chemical elements. Can be used to identify the presence and distribution of different phases in materials. Requires less sample material and therefore can provide information on microscopic objects. Handling of small quantities is not always simple. Higher accuracy of weighing is necessary (e.g. use of accurate balance). Sample surface preparation can have a major impact on measurement results.
Sources: pubmed.ncbi.nlm.nih.gov
The word analgesic derives from Greek an- (ἀν-, "without"), álgos (ἄλγος, "pain"), and -ikos (-ικος, forming adjectives). Such drugs were usually known as "anodynes" before the 20th century. Analgesics are typically classified based on their mechanism of action. Paracetamol, also known as acetaminophen, is a medication used to treat pain and fever. It is typically used for mild to moderate pain. In combination with opioid pain medication, paracetamol is now used for more severe pain such as cancer pain and after surgery. It is typically used either by mouth or rectally but is also available intravenously. Effects last between two and four hours. Paracetamol is classified as a mild analgesic, and is generally safe at recommended doses. Nonsteroidal anti-inflammatory drugs (NSAIDs) are a drug class that groups together drugs that decrease pain and lower fever, and, in higher doses, decrease inflammation. The most prominent members of this group of drugs—aspirin, ibuprofen, naproxen, and diclofenac—are all available over the counter in most countries.
People can also develop CJD because they carry a mutation of the gene that codes for the prion protein (PRNP), located on chromosome 202p12-pter. This occurs in only 10–15% of all CJD cases. In sporadic cases, the misfolding of the prion protein is a process that is hypothesized to occur as a result of the effects of aging on cellular machinery, explaining why the disease often appears later in life. An EU study determined that "87% of cases were sporadic, 8% genetic, 5% iatrogenic and less than 1% variant." Testing for CJD has historically been problematic, due to the nonspecific nature of early symptoms and difficulty in safely obtaining brain tissue for confirmation. The diagnosis may initially be suspected in a person with rapidly progressing dementia, particularly when it is also found with the characteristic medical signs and symptoms such as involuntary muscle jerking, difficulty with coordination/balance and walking, and visual disturbances. Further testing can support the diagnosis and may include:
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In 1969, after completing her medical training, she became a lecturer at the Department of Bacteriology and Immunology in Glasgow's Western Infirmary teaching hospital. While working at the hospital she carried out research on the role of intra-epithelial lymphocytes in intestinal immunity, receiving her PhD in 1974. In 1975, she was appointed as a senior lecturer at the University of Edinburgh, also becoming a consultant at the Gastrointestinal Unit at the Western General Hospital in Edinburgh. In 1987 she was appointed to a personal professorship in gastroenterology. From 1991 to 1994 she was head of the Department of Medicine at the university. She published more than 250 papers in peer-reviewed academic journals, published three books and contributed chapters to many other books. Her research provided new insights into the mechanisms responsible for Crohn's and coeliac diseases which led to significant advances in the therapy of these conditions. She also carried out significant research on oral tolerance. She served on the Committee on Safety of Medicines, the Medical Research Council Gene Therapy Advisory Board, and the Spongiform Encephalopathy Advisory Committee. At the time of her death she was president of the Society for Mucosal Immunology. She was a consultant providing advice and training to the International Centre for Diarrhoeal Disease Research in Bangladesh.
From Greek βίος (bíos) 'life', (from Proto-Indo-European root *gwei-, to live) and λογία (logia) 'study of'. The compound appears in the title of Volume 3 of Michael Christoph Hanow's Philosophiae naturalis sive physicae dogmaticae: Geologia, biologia, phytologia generalis et dendrologia, published in 1766. The term biology in its modern sense appears to have been introduced independently by Thomas Beddoes (in 1799), Karl Friedrich Burdach (in 1800), Gottfried Reinhold Treviranus (Biologie oder Philosophie der lebenden Natur, 1802) and Jean-Baptiste Lamarck (Hydrogéologie, 1802).
Sources: en.wikipedia.org
Modern definitions are concerned with the fundamental chemical reactions common to all acids. Most acids encountered in everyday life are aqueous solutions, or can be dissolved in water, so the Arrhenius and Brønsted–Lowry definitions are the most relevant. The Brønsted–Lowry definition is the most widely used definition; unless otherwise specified, acid–base reactions are assumed to involve the transfer of a proton (H+) from an acid to a base. Hydronium ions are acids according to all three definitions. Although alcohols and amines can be Brønsted–Lowry acids, they can also function as Lewis bases due to the lone pairs of electrons on their oxygen and nitrogen atoms.
Complete list of OTC drugs "Over-the-Counter Medicines Guide" Archived 9 March 2021 at the Wayback Machine, Tool Box at ConsumerMedSafety.org Over-the-counter (OTC) medicines at FamilyDoctor.org, maintained by the American Academy of Family Physicians. Contains extensive information on over-the-counter drugs and their responsible use, including specific guidance on several drug classes in question-and-answer format and information on common drug interactions. UK Medicines and Healthcare Products Regulatory Agency list of substances on general sales list Archived 7 March 2014 at the Wayback Machine National Institute on Drug Abuse: "NIDA for Teens: Cough and Cold Medicine (DXM and Codeine Syrup)"
Calmodulin-like protein 5 is a protein that in humans is encoded by the CALML5 gene. This gene encodes a novel calcium binding protein expressed in the epidermis and related to the calmodulin family of calcium binding proteins. Functional studies with recombinant protein demonstrate it does bind calcium and undergoes a conformational change when it does so. Abundant expression is detected only in reconstructed epidermis and is restricted to differentiating keratinocytes. In addition, it can associate with transglutaminase 3, shown to be a key enzyme in the terminal differentiation of keratinocytes. Human CALML5 genome location and CALML5 gene details page in the UCSC Genome Browser. Overview of all the structural information available in the PDB for UniProt: Q9NZT1 (Human Calmodulin-like protein 5) at the PDBe-KB.
Because DNA collects mutations over time, which are then inherited, it contains historical information, and, by comparing DNA sequences, geneticists can infer the evolutionary history of organisms, their phylogeny. This field of phylogenetics is a powerful tool in evolutionary biology. If DNA sequences within a species are compared, population geneticists can learn the history of particular populations. This can be used in studies ranging from ecological genetics to anthropology. DNA as a storage device for information has enormous potential since it has much higher storage density compared to electronic devices. However, high costs, slow read and write times (memory latency), and insufficient reliability has prevented its practical use.
Sources: en.wikipedia.org
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.
Intranasal delivery is the route described in most published work. It is used because the peptide is degraded quickly once it reaches circulation. Direct evidence of brain penetration in humans is lacking.
Most trials are small, regionally concentrated, and often lack rigorous blinding or placebo control. Independent replication is limited. Reviews in English generally rate the evidence as preliminary.
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.