Everything below concerns Selank. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-06-28. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C33H57N11O9 | Free peptide form |
| Molecular mass | About 751.9 Da | Calculated average mass |
| Amino acid sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form TKPRPGP |
| Structural basis | Tuftsin analogue | Extended version of a natural tetrapeptide |
| Development origin | Russian Academy of Sciences | Work carried out from the 1980s onward |
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.
Reverse-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres is the standard purity method. Mass spectrometry, typically electrospray ionisation, confirms identity through the expected mass-to-charge pattern. Amino acid analysis can verify composition independently. Chiral purity requires separate techniques such as derivatisation followed by chromatographic separation, and such data are rarely reported for research-grade material.
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.
=== Medication === Infective endocarditis: An infection of the endocardium caused by enterococcus; used when the organism is not sensitive to gentamicin Tuberculosis: Used in combination with other antibiotics. For active tuberculosis it is often given together with isoniazid, rifampicin, and pyrazinamide. It is not the first-line treatment, except in medically under-served populations where the cost of more expensive treatments is prohibitive. It may be useful in cases where resistance to other drugs is identified. Plague (Yersinia pestis): Has historically been used as the first-line treatment. However streptomycin is approved for this purpose only by the US Food and Drug Administration. In veterinary medicine, streptomycin is the first-line antibiotic for use against gram negative bacteria in large animals (horses, cattle, sheep, etc.). It is commonly combined with procaine penicillin for intramuscular injection. Tularemia infections have been treated mostly with streptomycin. Streptomycin is traditionally given intramuscularly, and in many nations is only licensed to be administered intramuscularly, though in some regions the drug may also be administered intravenously.
=== Cell integrity loss === Cell integrity loss is caused by bacteria releasing dissolved algicidal compounds, which are toxic to algae, into the surrounding water, causing rapid cell lysis of algae cells. Cell lysis occurs when algicidal enzymes or small molecules degrade cell walls and membranes, causing structural collapse. While most compounds released by algicidal bacteria cause cell lysis by damaging the algae cells walls, other lysis inducing mechanisms can include ion permeability disruption, and acidification of the cytoplasm by small molecules passing through the cell wall. An example of a bacterium which causes cell integrity loss is a strain of Alteromonas abrolhosensis, named JY‑JZ1, which when cultured, showed strong algicidal activity. Through microscopy, researchers found that algal cells exposed to this bacterium had damaged cell membranes and leaked intracellular contents which indicates cell death by lysis.
=== March === 1 March – First Minister Humza Yousaf announces that his wife, Nadia El-Nakla, is expecting a baby in July, making him the first Scottish First Minister to become a parent while in office. 7 March – The Scottish Government announces an independent public inquiry into the police handling of the Emma Caldwell murder investigation. Police Scotland announces it will no longer investigate every low level crime following the success of a pilot project. 8 March – The creators of Wirdle, a Shetland dialect version of the Wordle game, announce the game's withdrawal following legal threats from The New York Times, owners of the original game. 9 March – A Daily Telegraph report alleging a conflict-of-interest involving First Minister Humza Yousaf after the Scottish Government donated £250,000 to the UN agency UNRWA, which supports Palestinian refugees, is rejected by Yousaf as an "outrageous smear" and a "far right conspiracy". 10 March – The Duke of Edinburgh is awarded the Order of the Thistle by Charles III, Scotland's highest royal honour. Creative Scotland launches an investigation into a decision to provide nearly £85,000 of public money for an arts project involving "hardcore" sex performances. 11 March – The driver of a double decker bus is arrested after the vehicle's roof is ripped off after crashing into a railway bridge in West Lothian. No passengers were aboard the bus at the time. 12 March – Professor Jason Leitch announces he will leave his role as National Clinical Director at the end of April.
The Fascial Net Plastination Project (FNPP) is an anatomical research initiative led by fascia researcher Robert Schleip. The project aims to enhance the study of fascia through the technique of plastination. Led by an international team of fascia experts and anatomists, the FNPP resulted in the creation of a full-body fascia plastinate known as FR:EIA (Fascia Revealed: Educating Interconnected Anatomy). This plastinate provides a detailed view of the human fascial network, allowing for a better understanding of its structure and function as an interconnected tissue throughout the body. FR:EIA was unveiled at the 2021 Fascia Research Congress and is currently exhibited at the Body Worlds exhibition in Berlin. This project represents a significant contribution to the visualization of fascia and has the potential to influence future research in fields such as medicine, physical therapy, and movement science.
Sources: en.wikipedia.org
Severe amoebic colitis: Fulminant amoebic colitis is associated with high case fatality and can occur in patients infected with the parasite Entamoeba histolytica after exposure to corticosteroid medications. Neuropsychiatric: steroid psychosis, and anxiety, depression. Therapeutic doses may cause a feeling of artificial well-being known as "steroid euphoria". Rare case reports of corticosteroid misuse, addiction, and dependence due to euphoria exist. The neuropsychiatric effects are partly mediated by sensitization of the body to the actions of adrenaline. Therapeutically, the bulk of corticosteroid dose is given in the morning to mimic the body's diurnal rhythm; if given at night, the feeling of being energized will interfere with sleep. An extensive review is provided by Flores and Gumina. Cardiovascular: Corticosteroids can cause sodium retention through a direct action on the kidney, in a manner analogous to the mineralocorticoid aldosterone. This can result in fluid retention and hypertension. Metabolic: Corticosteroids cause a movement of body fat to the face and torso, resulting in "moon face", "buffalo hump", and "pot belly" or "beer belly", and cause movement of body fat away from the limbs. This has been termed corticosteroid-induced lipodystrophy. Due to the diversion of amino-acids to glucose, they are considered anti-anabolic, and long term therapy can cause muscle wasting (muscle atrophy).
In regions such as the gingiva and parts of the hard palate, oral mucosa is attached directly to the periosteum of underlying bone, with no intervening submucosa. This arrangement is called a mucoperiosteum and provides a firm, inelastic attachment. A variable number of Fordyce spots or granules are scattered throughout the nonkeratinized tissue. These are a normal variant, visible as small, yellowish bumps on the surface of the mucosa. They correspond to deposits of sebum from misplaced sebaceous glands in the submucosa that are usually associated with hair follicles. A basal lamina (basement membrane without aid of the microscope) is at the interface between the oral epithelium and lamina propria similar to the epidermis and dermis.
In the 1970s, bodybuilding had major publicity thanks to the appearance of Arnold Schwarzenegger, Franco Columbu, Lou Ferrigno, Mike Mentzer and others in the 1977 docudrama Pumping Iron. By this time, the IFBB dominated the competitive bodybuilding landscape and the Amateur Athletic Union (AAU) took a back seat. The National Physique Committee (NPC) was formed in 1981 by Jim Manion, who had just stepped down as chairman of the AAU Physique Committee. The NPC has gone on to become the most successful bodybuilding organization in the United States and is the amateur division of the IFBB. The late 1980s and early 1990s saw the decline of AAU-sponsored bodybuilding contests. In 1999, the AAU voted to discontinue its bodybuilding events.
Also, during the 1981 tour, veteran session drummer Andy Newmark stepped in briefly for Knudsen, who was then in rehab. And by the end of 1981, even Simmons had left the band. Now with no remaining original members and a "leader" in McDonald who was ready for a solo career, the group elected instead to disband after a rehearsal without Simmons, according to an interview with McDonald for Listen to the Music, the Doobie Brothers' official video history/documentary released in 1989. He went on to say that by that point they could not have gotten further away from the Doobies sound if they had tried. Simmons, already at work on his first solo album, Arcade, rejoined for a 1982 farewell tour on the condition that this truly would be the end of the Doobie Brothers. At their last concert at the Greek Theatre in Berkeley, California, on September 11, 1982, they were joined onstage by founding member Tom Johnston for what was presumed to be the final rendition of his staple, "China Grove". Former members Porter, Hossack and Hartman subsequently took the stage for an extended version of "Listen to the Music". Knudsen sang lead vocals while Johnston, Simmons and McFee traded licks on guitar. The live album Farewell Tour was released in 1983 and the Greek Theatre concert was released in 2011 as Live at the Greek Theatre 1982.
Metalloprotein is a generic term for a protein that contains a metal ion cofactor. A large proportion of all proteins are part of this category. For instance, at least 1000 human proteins (out of ~20,000) contain zinc-binding protein domains although there may be up to 3000 human zinc metalloproteins.
Sources: en.wikipedia.org
==== Two strategies for searching for intelligent signals ==== Kardashev then analyzed various models and hypotheses of the evolution of civilization. Answering the question of the Russian astronomer Iosif Shklovsky, who in an article published in 1977 entitled Possibility of the Intelligent Life in the Universe Being Unique found it strange that the "shock wave of intelligence" of a supercivilization had not yet reached the limits of the whole Universe, Kardashev put forward two explanatory hypotheses. In the first, he postulated that it would not be useful for a supercivilization to expand the space it occupies in order to maintain its activity, and in the second, it is possible that a civilization, instead of dispersing itself in space, would rather continue its activities of information analysis in order to discover new fundamental laws (such as the exploration of the microcosm, or black holes for example). However, such civilization activities require the use of abundant energy. According to the laws of thermodynamics, an important part of this consumed energy must be converted into radiation of a bolometric magnitude approximately equal to that of the radiation background surrounding the source. The spectral distribution of this intensity must be close to that of a black body. This would be a possible way to search for extraterrestrial civilizations. Such energy consumption would also require a large amount of solid matter for stellar engineering activities, which Kardashev called "cosmic miracles".
Diffuse connective tissue diseases Rheumatoid arthritis Juvenile arthritis Systemic lupus erythematosus Sjögren syndrome Scleroderma Polymyositis Dermatomyositis Behçet's disease Relapsing polychondritis Arthritis associated with spondylitis (i.e. spondarthritis) Ankylosing spondylitis Reactive arthritis Psoriatic arthritis Osteoarthritis (i.e. osteoarthrosis, degenerative joint disease) Rheumatic syndromes associated with infectious agents (direct and indirect or reactive) Metabolic and endocrine diseases associated with rheumatic states Gout, pseudogout Neoplasms Neurovascular disorders Bone and cartilage disorders Extraarticular disorders Bursitis/Tendinitis of the shoulder, wrist, biceps, leg, knee cap (patella), ankle, hip, and Achilles tendon Capsulitis Miscellaneous disorders associated with articular manifestations Palindromic rheumatism is thought to be a form of rheumatoid arthritis.
== Function and regulation == Most of the glucokinase in a mammal is found in the liver, and glucokinase provides approximately 95% of the hexokinase activity in hepatocytes. Phosphorylation of glucose to glucose-6-phosphate (G6P) by glucokinase is the first step of both glycogen synthesis and glycolysis in the liver. When ample glucose is available, glycogen synthesis proceeds at the periphery of the hepatocytes until the cells are replete with glycogen. Excess glucose is then increasingly converted into triglycerides for export and storage in adipose tissue. Glucokinase activity in the cytoplasm rises and falls with available glucose. G6P, the product of glucokinase, is the principal substrate of glycogen synthesis, and glucokinase has a close functional and regulatory association with glycogen synthesis. When maximally active, GK and glycogen synthase appears to be located in the same peripheral areas of hepatocyte cytoplasm in which glycogen synthesis occurs. The supply of G6P affects the rate of glycogen synthesis not only as the primary substrate, but by direct stimulation of glycogen synthase and inhibition of glycogen phosphorylase. Glucokinase activity can be rapidly amplified or damped in response to changes in the glucose supply, typically resulting from eating and fasting. Regulation occurs at several levels and speeds, and is influenced by many factors that affect mainly two general mechanisms:
=== Chronic disease === Individuals who have cirrhosis or chronic liver disease may develop gynecomastia for several reasons. Those diagnosed with cirrhosis tend to have increased secretion of the androgenic hormone androstenedione from the adrenal glands, increased conversion of this hormone into various types of estrogen, and increased levels of SHBG, which leads to decreased blood levels of free testosterone. Around 10–40% of males with Graves' disease (a common form of hyperthyroidism) experience gynecomastia. Increased conversion of testosterone to estrogen by increased aromatase activity, increased levels of SHBG and increased production of testosterone and estradiol by the testes due to elevated levels of LH cause the gynecomastia. Proper treatment of the hyperthyroidism can lead to the resolution of the gynecomastia.
Enamel is the hardest substance in the human body and contains the highest percentage of minerals, 96%, with water and organic material composing the rest. The primary mineral is hydroxyapatite, which is a crystalline calcium phosphate. Enamel is formed on the tooth while the tooth is developing within the gum, before it erupts into the mouth. Once fully formed, it does not contain blood vessels or nerves. Remineralisation of teeth can repair damage to the tooth to a certain degree but damage beyond that cannot be repaired by the body. The maintenance and repair of human tooth enamel is one of the primary concerns of dentistry. In humans, enamel varies in thickness over the surface of the tooth, often thickest at the cusp, up to 2.5 mm, and thinnest at its border with the cementum at the cementoenamel junction. The normal color of enamel varies from light yellow to grayish (bluish) white. At the edges of teeth where there is no dentin underlying the enamel, the color sometimes has a slightly blue tone. Since enamel is semitranslucent, the color of dentin and any material underneath the enamel strongly affects the appearance of a tooth. The enamel on primary teeth has a more opaque crystalline form and thus appears whiter than on permanent teeth. The large amount of mineral in enamel accounts not only for its strength but also for its brittleness. Tooth enamel ranks 5 on Mohs hardness scale and has a Young's modulus of 83 GPa. Dentin, less mineralized and less brittle, 3–4 in hardness, compensates for enamel and is necessary as a support.
Sources: en.wikipedia.org
It is a seven-amino-acid peptide, Thr-Lys-Pro-Arg-Pro-Gly-Pro, produced by chemical synthesis rather than extracted from biological tissue. Its design is based on tuftsin, a natural immunomodulatory tetrapeptide. The C-terminal Pro-Gly-Pro segment is a common stabilising motif in short regulatory peptides.
The core four residues correspond to tuftsin, which occurs naturally as part of immunoglobulin G. The full seven-residue sequence, however, is not a known endogenous peptide. It is a laboratory-designed analogue intended to combine tuftsin-like activity with greater resistance to breakdown.
No single receptor has been confirmed as the primary target. Reports describe involvement of the GABAergic system, interference with enkephalin degradation, and shifts in neurotrophic factor expression. Because these observations come from different models and assays, they have not yet been integrated into one accepted mechanism.
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.