GABA-A receptor raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2025-08-29 and is reviewed periodically as new material appears.
Selank is not a naturally occurring peptide and has no known endogenous counterpart in human physiology. Russian-language sources frequently call it TP-7, while English-language sources use the name Selank almost exclusively. Database indexing is uneven, partly because early reports appeared in regional journals that are not widely cataloged. Some summaries describe the material as a tuftsin analog and others as a synthetic heptapeptide; the labels overlap rather than conflict. Citing the primary sequence resolves ambiguity more reliably than the research or trade name alone.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter notation. Its structure consists of the immunomodulatory tetrapeptide tuftsin, Thr-Lys-Pro-Arg, extended at the carboxyl terminus by a Pro-Gly-Pro segment. The molecular formula is commonly given as C33H57N11O9, corresponding to a monoisotopic mass near 751.4 Da and an average molecular mass near 751.9 Da. All seven residues are proteinogenic amino acids, and the molecule carries no modified side chains or non-natural linkages.
Solubility behavior is a practical concern for handling. Selank dissolves readily in water and in common aqueous buffers, which simplifies preparation of working solutions. The choice of solvent, ionic strength, and pH can influence aggregation over time, particularly at higher concentrations. Aqueous solutions are typically sterile-filtered before use. Because stability depends on several variables, storage and handling notes should be treated as general guidance rather than fixed rules, and specific values are best confirmed against a certificate of analysis for each batch.
Characterization of Selank in a laboratory setting relies on standard peptide methods. Reverse-phase high-performance liquid chromatography separates the target from related impurities and provides a purity figure, commonly reported as 95 percent or higher. Mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, confirms the molecular mass and helps detect truncation or modification. Amino acid analysis can verify composition when a sequence-level check is needed. These techniques together establish identity and purity for a given lot.
| Property | Value | Notes |
|---|---|---|
| Peptide sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Seven residues; tuftsin plus a Pro-Gly-Pro tail |
| Molecular formula | C33H57N11O9 | Commonly reported value for the free peptide |
| Monoisotopic mass | Roughly 751.4 Da | Average molecular mass near 751.9 Da |
| Appearance | White to off-white powder | Typically supplied as a lyophilized solid |
| Solubility class | Freely soluble in water | Also dissolves in saline and other polar solvents |
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.
Regulatory treatment varies by jurisdiction. In Russia the compound is a registered prescription product, while in the European Union and the United States it is generally handled as a research chemical without a marketing authorization. Suppliers therefore operate outside pharmaceutical oversight, and buyers rely on supplier documentation for purity and identity claims. Chain of custody and third-party testing are the main verification tools. Analysts note that the absence of a pharmacopoeial monograph for research-grade material limits standardization across vendors.
Purity assessment relies mainly on reverse-phase high-performance liquid chromatography with ultraviolet detection. Because the peptide lacks a strong chromophore, detection often uses backbone absorbance near 214 nm. Identity is confirmed by mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, comparing the measured mass against the expected value. Amino acid analysis can verify composition after acid hydrolysis. Diastereomer content and residual counterions are reported less often, although both can influence biological assays.
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.
Tuftsin, the parent structure, is a naturally occurring immunomodulatory tetrapeptide released from the Fc region of immunoglobulin G by spleen enzymes. Selank extends this four-residue sequence with three additional amino acids. The stated rationale is that the added tail slows enzymatic breakdown and may influence receptor interactions. How the full heptapeptide behaves at the molecular level is not firmly established, and proposed mechanisms often involve indirect modulation of neurotransmitter or immune signaling rather than a single defined target.
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.
== Use and effects == (R)-MDMA has a dose of 125 to 300 mg orally and a duration of 3.5 to 5.2 hours. It has been estimated that doses of 125 mg MDMA, 100 mg (S)-MDMA, and 300 mg (R)-MDMA are equivalent. The first modern clinical study of the comparative effects of MDMA, (R)-MDMA, and (S)-MDMA was published in August 2024. It compared 125 mg MDMA, 125 mg (S)-MDMA, 125 and 250 mg (R)-MDMA, and placebo. (R)-MDMA increased any drug effect, good drug effect, drug liking, stimulation, drug high, alteration of vision, and alteration of sense of time ratings similarly to MDMA and (S)-MDMA. However, (S)-MDMA 125 mg was more potent in increasing subjective effects, including stimulation, drug high, happy, and open, among others, than (R)-MDMA 125 or 250 mg or MDMA 125 mg. Ratings of bad drug effect and fear were minimal with MDMA, (R)-MDMA, and (S)-MDMA. In contrast to expectations, (R)-MDMA did not produce more psychedelic-like effects than (S)-MDMA. Besides subjective effects, (R)-MDMA increased heart rate, blood pressure, and body temperature similarly to MDMA and (S)-MDMA, though it was less potent in producing these effects. Body temperature was notably increased to the same extent with (R)-MDMA 250 mg as with MDMA 125 mg and (S)-MDMA 125 mg. The differences in effects between (R)-MDMA and (S)-MDMA may reflect the higher potency of (S)-MDMA rather than actual qualitative differences between the effects of (S)-MDMA and (R)-MDMA. It was estimated that equivalent effects would be expected with (S)-MDMA 100 mg, MDMA 125 mg, and (R)-MDMA 300 mg.
=== Tendons === Quinolones are associated with a risk of tendonitis and tendon rupture; a 2013 review found the incidence of tendon injury among those taking fluoroquinolones to be between 0.08 and 0.20%. The risk appears to be higher among people older than 60 and those also taking corticosteroids; the risk also may be higher among people who are male, have a pre-existing joint or tendon issue, have kidney disease, or are highly active. Some experts have advised avoidance of fluoroquinolones in athletes. If tendonitis occurs, it generally appears within one month, and the most common tendon injured appears to be the Achilles tendon. The cause is not well understood.
Since 1986, the restaurant has issued a calendar featuring Hooters Girls, with signings taking place in some of their restaurants. Since 1996, Hooters has held Miss Hooters International Swimsuit Pageant, a competition of Hooters Girls from around the world. The pageant once aired on Spike TV and is now livestreamed to Hooters restaurants and eventually posted on YouTube. An African-American woman won the Miss Hooters pageant for the first time in 2010: LeAngela Davis of Columbus, Ohio.
=== Quantification in disease === Elevation of serum, plasma, or tissue SP and/or its receptor (NK1R) has been associated with many diseases: sickle cell crisis; inflammatory bowel disease; major depression and related disorders; fibromyalgia; rheumatological; and infections such as HIV/AIDS and respiratory syncytial virus, as well as in cancer. When assayed in the human, the observed variability of the SP concentrations are large, and in some cases the assay methodology is questionable. SP concentrations cannot yet be used to diagnose disease clinically or gauge disease severity. It is not yet known whether changes in concentration of SP or density of its receptors is the cause of any given disease, or an effect.
Germany's Federal Agency for Civic Education (German:Bundeszentrale für politische Bildung, or bpb) estimated that around 10,000 former athletes bear the physical and mental scars of years of drug abuse; one of them, Rica Reinisch, a triple Olympic champion and world record-setter at the 1980 Summer Olympics, has since had numerous miscarriages and recurring ovarian cysts. Two former Dynamo Berlin club doctors, Dieter Binus, chief of the national women's swim team from 1976 to 1980, and Bernd Pansold, in charge of the sports medicine center in East Berlin, were committed for trial for allegedly supplying 19 teenagers with illegal substances. Binus was sentenced in August, Pansold in December 1998 – both were found guilty of administering hormones to underage female athletes from 1975 to 1984. Virtually no East German athlete ever failed an official drugs test, though Stasi files show that many did produce failed tests at Kreischa, the Saxon laboratory (German:Zentrales Dopingkontroll-Labor des Sportmedizinischen Dienstes) that was at the time approved by the International Olympic Committee (IOC), now called the Institute of Doping Analysis and Sports Biochemistry (IDAS). In 2005, 15 years after the end of East Germany, the manufacturer of the drugs, Jenapharm, still found itself involved in numerous lawsuits from doping victims, being sued by almost 200 former athletes. Former Sport Club Dynamo athletes Daniela Hunger and Andrea Pollack publicly admitted to doping and accused their coaches for being responsible.
Sources: en.wikipedia.org
== Policy responses == There have been responses from both individual states and international forces, but neither have yet controlled the illicit drug trade throughout the region. Navies have been a core part of this response, often reacting prior to foreign policy guidance. There have been some notable actions among these coast guards and navies, including some cross-state collaboration. The Indian Navy has established cooperative activities with South East Asia, and has also assisted East African and island states. The Bangladesh Navy has also prioritised maritime security as an essential element to the stability of the country, so that they can benefit from the blue economy for economic development. In order to establish the security necessary for this, they have facilitated joint exercises with the US Navy and Special Force in the Exclusive Economic zone, which both Japan and India have partaken in during the last decade. The Bangladesh Navy has also engaged in specific anti-smuggling operations, which target drug trafficking. Additionally, the Asian coastguard has been given specialised training and technical equipment to tackle the maritime drug trade, both in the Bay of Bengal and Southeast Asian waters. There have also been a number of notable regional responses among the states affected by the illicit maritime drug trade, which is evident throughout the policy of these countries. The Southern African Development Community (SADC) has established an operative maritime committee working towards regional coordination.
== Reasons == Within anthropology, the study of the body as a boundary has been long debated. In 1909, Van Gennep described bodily transformations, including tattooing, scarification, and painting, as rites of passage. In 1963, Lévi-Strauss described the body as a surface waiting for the imprintation of culture. Turner (1980) first used the term "social skin" in his detailed discussion of how Kayapo culture was constructed and expressed through individual bodies. Inscribed skin highlights an issue that has been central to anthropology since its inception: the question of boundaries between the individual and society, between societies, and between representation and experiences.
The WHO-convened Global Study of Origins of SARS-CoV-2 or the Joint WHO-China Study was a collaborative study between the World Health Organization and the Government of China on the origins of COVID-19. The study was commissioned by the Director-General of the World Health Organization following a request by the 2020 World Health Assembly in which 122 WHO members proposed a motion, which included a call for a "comprehensive, independent and impartial" study into the COVID-19 pandemic" The WHO disbanded the team and proposed a new panel called Scientific Advisory Group for Origins of Novel Pathogens.
=== Climate change and the environment === One of Trump's Executive Orders rescinded a Biden Order which rescinded a Trump order which withdrew the United States from the Paris Climate Accords. This chain of orders effectively was a re-leaving of the order, "Putting America First In International Environmental Agreements". The end result being that the United States is no longer a member. The order dissolved the following councils and offices by rescinding the Executive Order 14008 of January 27, 2021 (Tackling the Climate Crisis at Home and Abroad).
Sources: en.wikipedia.org
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter code. It combines the tetrapeptide tuftsin with a carboxyl-terminal Pro-Gly-Pro extension. This full sequence identifies the molecule more precisely than the research name.
No peptide with this exact sequence has been identified as an endogenous substance. It is a laboratory-designed analog of tuftsin, a naturally occurring immunomodulatory tetrapeptide. The Pro-Gly-Pro extension has no known natural source.
Proline introduces conformational constraints that make a peptide less accessible to common peptidases. This is a standard stabilization strategy in peptide design. The added residues also increase the distance between the active tuftsin portion and typical cleavage sites.
Reverse-phase HPLC is the usual method and gives a percentage purity value. Mass spectrometry then confirms the molecular mass. Together they provide a basic identity and purity profile for a lot.