GABA-A modulation raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-02-16. Anything still debated is marked as such rather than presented as settled.
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.
Quantification in biological matrices relies on liquid chromatography coupled to tandem mass spectrometry with stable-isotope internal standards. Low plasma concentrations and adsorption to container surfaces both complicate measurement. Solid-phase extraction is often needed to reduce matrix interference before injection. Reported limits of quantification differ widely between laboratories, which makes direct comparison of pharmacokinetic results difficult and limits meta-analysis.
Peptide bonds are vulnerable to protease attack, and Selank is no exception. Measured half-life in serum is short, on the order of minutes in several reports, which explains why intranasal administration is the common route described in the literature. Absorption across the nasal mucosa partially bypasses first-pass hepatic metabolism. Quantitative data on human bioavailability remain limited and are difficult to compare across studies.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Analog of the tetrapeptide tuftsin |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Reported consistently across pharmacopoeial descriptions |
| Appearance | White to off-white lyophilized powder | Typical form of research-grade material |
| Solubility | Freely soluble in water | Aqueous buffers; poor in nonpolar solvents |
| Typical storage temperature | -20 degrees Celsius | Lyophilized powder; protect from moisture |
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.
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.
The largest risk of relapse occurs within the first year post-discharge from eating disorder therapy treatment. Within the first two years post-discharge, approximately 31% of anorexia nervosa patients relapse. Many complications, both physical and psychological, improve or resolve with nutritional rehabilitation and adequate weight gain. Anorexia nervosa is estimated to occur in approximately 0.3–4.3% of women and 0.2–1% of men in Western countries at some point in their life. Levels in other countries are unclear due to undiagnosis and a lack of awareness, though it can be presumed it is more present in Western societies due to a higher focus on low body weight and beauty on social media and real life. There is an observation for an increase in the diagnosis of anorexia from the 20th century onwards: it is unclear whether this is due to an actual increase in its frequency or simply due to improved diagnostic capabilities. In 2013, it directly resulted in about 600 deaths globally, up from 400 deaths in 1990. Eating disorders also increase a person's risk of death from a wide range of other causes, including suicide. About 5% of people with anorexia die from complications over a ten-year period with medical complications and suicide being the primary and secondary causes of death respectively. Anorexia has one of the highest death rates among mental illnesses, second only to opioid overdoses.
== Etymology == In the Aztec language Nahuatl, the word for the product of this procedure is nixtamalli or nextamalli (pronounced [niʃtaˈmalːi] or [neʃtaˈmalːi]), which in turn has yielded Mexican Spanish nixtamal ([nistaˈmal]). The Nahuatl word is a compound of nextli, "ash", referring to the lye involved in its preparation, and tamalli, "unformed/cooked corn dough, tamal". The term nixtamalization can also be used to describe the removal of the pericarp from any grain by an alkali process, including maize, sorghum, and others. When the unaltered Spanish spelling nixtamalización is used in written English, however, it almost exclusively refers to maize. The labels on packages of commercially sold tortillas prepared with nixtamalized maize usually list corn treated with lime as an ingredient in English, while the Spanish versions list maíz nixtamalizado.
Black ants collect and store these and other seeds in their nest, where humans can gather them en masse. Up to half a pound (200 g) of seeds may be collected from one ant-heap. Although most ants survive attempts by humans to eradicate them, a few are highly endangered. These tend to be island species that have evolved specialized traits and risk being displaced by introduced ant species. Examples include the critically endangered Sri Lankan relict ant (Aneuretus simoni) and Adetomyrma venatrix of Madagascar.
The survival of Franz Joseph was also commemorated in Prague by erecting a new statue of St. Francis of Assisi, the patron saint of the emperor, on Charles Bridge. It was donated by Count Franz Anton von Kolowrat-Liebsteinsky, the first minister-president of the Austrian Empire.
== Function == Resistin is a multifunctional hormone that plays critical roles in metabolic regulation, inflammation, and innate immunity. In humans, resistin is primarily expressed by immune cells such as monocytes and macrophages, where it acts as a pro-inflammatory cytokine by stimulating the production of cytokines including IL-6, IL-1β, and TNF-α through activation of signaling pathways involving the TLR4 and CAP1 receptors. Beyond its pro-inflammatory effects, resistin also demonstrates direct antimicrobial activity by damaging bacterial membranes, and it modulates immune responses by recruiting and activating immune cells, promoting chemokine production, and enhancing the formation of neutrophil extracellular traps (NETs). Notably, resistin exhibits bidirectional immunomodulatory properties: while it can amplify inflammation in response to certain stimuli, it can also attenuate excessive inflammatory responses triggered by bacterial products such as lipopolysaccharide (LPS), potentially by competing for TLR4 binding or directly neutralizing LPS. This dual functionality positions resistin as an important regulator of host defense and inflammatory balance in both health and disease.
Sources: en.wikipedia.org
=== Other === Some routes of administration such as nasal sprays and inhalers generally result in a faster onset of high blood levels, which can provide more immediate analgesia but also more severe side effects, especially in overdose. The much higher cost of some of these appliances may not be justified by marginal benefit compared with buccal or oral options. Intranasal fentanyl appears to be equally effective as IV morphine and superior to intramuscular morphine for the management of acute hospital pain. A fentanyl patient-controlled transdermal system (PCTS) is under development, which aims to allow patients to control the administration of fentanyl through the skin to treat postoperative pain. The technology consists of a "preprogrammed, self-contained drug-delivery system" that uses electrotransport technology to administer on-demand doses of 40 μg of fentanyl hydrochloride over ten minutes. In a 2004 experiment including 189 patients with moderate to severe postoperative pain up to 24 hours after major surgery, 25% of patients withdrew due to inadequate analgesia. However, the PCTS method proved superior to the placebo, showing lower mean VAS pain scores and having no significant respiratory depression effects.
=== Sports and entertainment === Jack Kramer, 1939: tennis player in International Tennis Hall of Fame Tom Tellez, 1951: former track coach at the University of Houston Darlene Hard, 1954: tennis player in International Tennis Hall of Fame Ivan Guevara, 1955: former college basketball coach at Whittier College and San Jose State University Barney Rosenzweig, 1955: television producer Jerry Pimm, 1956: former basketball coach at University of Utah Bobby Knoop, 1956: retired MLB second baseman for California Angels, Chicago White Sox, and Kansas City Royals Edward James Olmos, 1964: actor and director John Madrid, 1966: jazz and pop music trumpeter
For example, a number of males may break off from the main group in order to hunt or forage for food during the day, but at night they may return to join (fusion) the primary group to share food and partake in other activities. Many mammals exhibit this, such as primates (for example orangutans and spider monkeys), elephants, spotted hyenas, lions, and dolphins. Solitary animals defend a territory and avoid social interactions with the members of its species, except during breeding season. This is to avoid resource competition, as two individuals of the same species would occupy the same niche, and to prevent depletion of food. A solitary animal, while foraging, can also be less conspicuous to predators or prey.
Typically, the base for lean is a strong prescription cold medicine, specifically cough syrup that contains both promethazine and codeine. Other preparations use codeine/guaifenasin, hydrocodone/chlorphenamine, hydrocodone/APAP, and hydrocodone/homatropine. Over-the-counter cold medicines that contain dextromethorphan (often paired with guaifenasin or acetaminophen) as the active ingredient have also been used, as they do not require acquiring a prescription. To create a drinkable mixture, the cough syrup is combined with soft drinks, especially fruit-flavored drinks such as Sprite, Mountain Dew, or Fanta, and is often served in foam cups. A hard candy, usually a Jolly Rancher, may be added to give the mixture a sweeter flavor. Masking the undesired taste may impair judgment of the potency, which is a factor in overdosing.
Application of hot air (convective or direct drying). Air heating increases the drying force for heat transfer and accelerates drying. It also reduces air relative humidity, further increasing the driving force for drying. In the falling rate period, as moisture content falls, the solids heat up and the higher temperatures speed up diffusion of water from the interior of the solid to the surface. However, product quality considerations limit the applicable rise to air temperature. Excessively hot air can almost completely dehydrate the solid surface, so that its pores shrink and almost close, leading to crust formation or "case hardening", which is usually undesirable. For instance in wood (timber) drying, air is heated (which speeds up drying) though some steam is also added to it (which hinders drying rate to a certain extent) in order to avoid excessive surface dehydration and product deformation owing to high moisture gradients across timber thickness. Spray drying belongs in this category. Indirect or contact drying (heating through a hot wall), as drum drying, vacuum drying. Again, higher wall temperatures will speed up drying but this is limited by product degradation or case-hardening. Drum drying belongs in this category. Dielectric drying (radiofrequency or microwaves being absorbed inside the material) is the focus of intense research nowadays. It may be used to assist air drying or vacuum drying. Researchers have found that microwave finish drying speeds up the otherwise very low drying rate at the end of the classical drying methods.
Sources: en.wikipedia.org
Selank is a synthetic seven-amino-acid peptide modeled on tuftsin, a fragment of the immunoglobulin G heavy chain. It was designed in Russia to combine anxiolytic and immunomodulatory properties in one molecule.
The first four residues of Selank reproduce the tuftsin sequence Thr-Lys-Pro-Arg. A Pro-Gly-Pro extension at the C-terminus was added to slow enzymatic breakdown and extend residence time.
It holds marketing authorization in Russia, where nasal drop formulations are sold. No equivalent approval exists in the European Union, the United States, or most other countries.
Dry powder is best kept sealed, protected from light, and held at minus 20 degrees Celsius or below. Desiccant packaging helps limit moisture uptake because the material is hygroscopic. A sealed vial should be allowed to equilibrate to room temperature before opening to reduce condensation.