Everything below concerns GABA-A receptor. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-04-28. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Dry storage temperature | -20 C or below | Sealed, desiccated, protected from light |
| Solution stability | Hours to days at 2-8 C | Depends on buffer and microbial load |
| Preferred pH range | Near neutral to slightly acidic | Alkaline pH accelerates hydrolysis |
| Main degradation routes | Hydrolysis and deamidation | No cysteine or methionine in sequence |
| Identity confirmation | Electrospray mass spectrometry | Observed mass compared with 751.9 Da |
Peptide stability depends strongly on temperature, moisture, and pH. Lyophilized Selank is generally most stable when stored cold and dry, with freezer temperatures commonly used for long-term storage. In solution, the compound is susceptible to hydrolysis and to microbial growth if it is not handled aseptically. The C-terminal proline-rich extension appears to slow enzymatic cleavage relative to tuftsin, though quantitative degradation rates vary with the matrix and the conditions tested. Published stability data specific to Selank remain sparse.
Quality assessment of Selank samples typically combines purity determination with identity confirmation and counter-ion analysis. Purity is usually reported as a percentage by chromatographic area, with values above 95 percent often quoted for research-grade material. Water content and residual solvents are checked in lyophilized batches because they affect both stability and accurate mass determination. A reported purity figure does not by itself establish that a sample is the intended sequence, so orthogonal methods are needed to rule out sequence isomers or truncation products.
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.
Animal studies have examined behaviour in tests of anxiety, memory retention and stress response, and several report changes in neurotrophic or neurotransmitter-related markers. The human evidence base is much smaller, consisting mainly of short trials conducted in Russia with limited reporting in English-language journals. Sample sizes are modest and outcome measures vary between studies, so the findings are best described as preliminary. Independent replication under modern trial standards has not been widely reported.
Outside its country of origin the compound is generally handled as a research chemical rather than an approved medicine. No regulatory approval from the United States Food and Drug Administration or the European Medicines Agency has been granted for human use. Identity and purity are normally checked by reverse-phase high-performance liquid chromatography, with mass spectrometry used to confirm the molecular mass. Lyophilised material is stored cold and desiccated, and repeated freeze-thaw cycles are avoided.
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.
As a consequence of the initial competing claims of discovery, an element naming controversy arose. Since the Soviets claimed to have first detected the new element they suggested the name kurchatovium (Ku) in honor of Igor Kurchatov (1903–1960), former head of Soviet nuclear research. This name had been used in books of the Soviet Bloc as the official name of the element. The Americans, however, proposed rutherfordium (Rf) for the new element to honor New Zealand physicist Ernest Rutherford, who is known as the "father" of nuclear physics. In 1992, the IUPAC/IUPAP Transfermium Working Group (TWG) assessed the claims of discovery and concluded that both teams provided contemporaneous evidence to the synthesis of element 104 in 1969, and that credit should be shared between the two groups. In particular, this involved the TWG performing a new retrospective reanalysis of the Russian work in the face of the later-discovered fact that there is no 0.3-second isotope of element 104: they reinterpreted the Dubna results as having been caused by a spontaneous fission branch of 259Rf. The American group wrote a scathing response to the findings of the TWG, stating that they had given too much emphasis on the results from the Dubna group. In particular they pointed out that the Russian group had altered the details of their claims several times over a period of 20 years, a fact that the Russian team does not deny.
==== After effects ==== The after effects can be defined as any residual effects which may remain after the experience has reached its conclusion. After effects depend on the substance and usage. This is colloquially known as a "hangover" for negative after effects of substances, such as alcohol, cocaine, and MDMA or an "afterglow" for describing a typically positive, pleasant effect, typically found in substances such as cannabis, LSD in low to high doses, and ketamine.
== Signs and symptoms == Signs and symptoms of TIA are widely variable and can mimic other neurologic conditions, making the clinical context and physical exam crucial in ruling in or out the diagnosis. The most common presenting symptoms of TIA are focal neurologic deficits, which can include, but are not limited to:
=== Archaeobotanical record and ruderal habitat === The interaction between the Moche and this wild species is supported by its ecological behavior and archaeobotanical findings in the La Libertad Region. Solanum pimpinellifolium behaves as a ruderal plant, proliferating naturally and constantly along the edges of irrigation canals, ditches, and humid depressions built by pre-Hispanic agricultural engineers. Contemporary botanical and archaeological inventories have recorded stable populations of this wild tomato growing directly over the cultural contexts of major Moche political-religious centers, such as the El Brujo Arqueological Complex (in the Chicama Valley) and near the Huaca del Rosario (in Magdalena de Cao). This resource holds high scientific and historical value because Peru is a key center of origin for the tomato, hosting 14 of the world's 17 tomato species. Research by Peru's Ministry of the Environment indicates that roughly 90% of the genes in modern commercially cultivated tomatoes worldwide originate from these wild Andean relatives, which contributed high natural sugar levels and lycopene content to ancient diets.
== Structure and general properties == L- and D-amino acids are usually enantiomers. The exceptions are two amino acids with two stereogenic centers, threonine and isoleucine. Aside from those two special cases, L- and D-amino acids have identical properties (color, solubility, melting point) under many conditions. In the biological context however, which is chiral, these enantiomers can behave very differently. Thus, D-amino acids have low nutritional value, in part because they are not digested well. They contain a carboxyl group at one end and a side chain group at the other end. They also contain an amine and hydrogen group on opposite ends, depending on which enantiomer one is looking at. They also do attain a chiral carbon center. This is why the molecules can exist in different stereoisomeric forms, and the orientation of the radical groups is what is only different between these enantiomers. D-glyceraldehyde on the other hand, contains a carbonyl group and hydroxy (alcohol) groups with the chiral carbon in the center. The orientation is again, different for L-glyceraldehyde.
Sources: en.wikipedia.org
=== Internal standards === A series of internal standards contain the same concentration of a chemical called the internal standard and different concentrations of the analyte. The internal standard should be chemically similar to the analyte, so that the two receive the same treatment during measurement. Internal standards are used to correct for loss of analyte during sample preparation, for example when the analyte is in a volatile solvent. If both the internal standard and the analyte lose solvent proportionally, their signals will remain identical and the ratio of their signals can be measured. Plotting the ratio of the analyte signal to the internal standard signal against the analyte concentration results in a calibration curve. Similar to the external calibration curve, the internal calibration curve also allows to calculate the concentration of analyte in an unknown sample.
Following three constitutional conferences, the British North America Act, 1867 officially proclaimed Canadian Confederation on July 1, 1867, initially with four provinces: Ontario, Quebec, Nova Scotia, and New Brunswick. Canada assumed control of Rupert's Land and the North-Western Territory to form the Northwest Territories, where the Métis' grievances ignited the Red River Rebellion and the creation of the province of Manitoba in July 1870. British Columbia and Vancouver Island (which had been united in 1866) joined the confederation in 1871 on the promise of a transcontinental railway extending to Victoria in the province within 10 years, while Prince Edward Island joined in 1873. In 1898, during the Klondike Gold Rush in the Northwest Territories, Parliament created the Yukon Territory. Alberta and Saskatchewan became provinces in 1905. Between 1871 and 1896, almost one quarter of the Canadian population emigrated south to the US. To settle the West and attract European immigrants, Canada sponsored the construction of three transcontinental railways, enacted the Dominion Lands Act and founded the North-West Mounted Police to maintain regional authority. This period of westward expansion and nation building resulted in the displacement of many Indigenous peoples of the Canadian Prairies to "Indian reserves", clearing the way for ethnic European block settlements. This caused the collapse of the Plains Bison in western Canada and the introduction of European cattle farms and wheat fields dominating the land.
=== Link to cancer === Post-translational modification of proteins is a generally used mechanism in eukaryotic cell signaling. Ubiquitylation, ubiquitin conjugation to proteins, is a crucial process for cell cycle progression and cell proliferation and development. Although ubiquitylation usually serves as a signal for protein degradation through the 26S proteasome, it could also serve for other fundamental cellular processes, in endocytosis, enzymatic activation and DNA repair. Moreover, since ubiquitylation functions to tightly regulate the cellular level of cyclins, its misregulation is expected to have severe impacts. First evidence of the importance of the ubiquitin/proteasome pathway in oncogenic processes was observed due to the high antitumor activity of proteasome inhibitors. Various studies have shown that defects or alterations in ubiquitylation processes are commonly associated with or present in human carcinoma. Malignancies could be developed through loss of function mutation directly at the tumor suppressor gene, increased activity of ubiquitylation, and/or indirect attenuation of ubiquitylation due to mutation in related proteins.
== International expansion == In a partnership with Persian Gulf company Alghanim Industries, the first international Slim Chickens opened in Salmiya, Kuwait, in May 2017. This location has since closed in 2022. The first UK location opened in London at 35 James Street in March 2018 via a partnership with Boparan Restaurant Group. A Cardiff branch opened in St David's 2 shopping centre in 2019. A Bristol branch opened in 2019 in the shopping area of Cabot Circus. A branch of this restaurant chain opened in Birmingham. The first branch in Kent, England, opened in Bluewater Shopping Centre in February 2020. In 2021, branches were opened in Bournemouth, Southampton and Plymouth. In 2023, branches in Bury St Edmunds and Crawley opened. As of May 2026, there are currently over 70 branches open in the UK. The first Turkish location opened on July 23rd, 2023 at Istanbul Airport. The first German location opened August 24, 2024 in Berlin. Meanwhile, the first Malaysian location opened July 15, 2025 in Subang Jaya.
Sources: en.wikipedia.org
By the mid-2020s, Zipline had become an example of a Silicon Valley startup whose most visible commercial activity occurred abroad rather than domestically, with most of its business based on government contracts for transporting medical supplies to remote or hard-to-reach areas in multiple African countries. In April 2024, Zipline completed its millionth commercial delivery, having flown more than 70 million autonomous commercial miles. In January 2026, Zipline completed its two millionth commercial delivery, with over 120 million autonomous miles flown.
=== Run-to-waste === In a run-to-waste system, nutrient and water solution is periodically applied to the medium surface. The method was invented in Bengal in 1946; for this reason it is sometimes referred to as "The Bengal System".
=== Helmut Schmidt === Finance Minister Helmut Schmidt (SPD) formed a coalition and he served as Chancellor from 1974 to 1982. Hans-Dietrich Genscher, a leading FDP official, became Vice-Chancellor and Foreign Minister. Schmidt, a strong supporter of the European Community (EC) and the Atlantic alliance, emphasised his commitment to "the political unification of Europe in partnership with the USA". Mounting external problems forced Schmidt to concentrate on foreign policy and limited the domestic reforms that he could carry out. The USSR upgraded its intermediate-range missiles, which Schmidt complained was an unacceptable threat to the balance of nuclear power, because it increased the likelihood of political coercion and required a western response. NATO responded in the form of its twin-track policy. The domestic reverberations were serious inside the SPD, and undermined its coalition with the FDP. One of his major successes, in collaboration with French President Valéry Giscard d'Estaing, was the launching of the European Monetary System (EMS) in April 1978.
The activity of GSK-3 is far greater in the nucleus and mitochondria than in the cytosol in cortical neurons, while the phosphorylation of Beta-catenin by GSK-3 is mediated by the binding of both proteins to Axin, a scaffold protein, allowing Beta-catenin to access the active site of GSK-3. Insulin indirectly inactivates GSK3 via downstream phosphorylation of the specific serine residues Ser21 and Ser9 in GSK-3 isoforms α and β, respectively, via the PI3K/Akt pathway (protein kinase B).
Bonaparte's reign over Europe sowed the seeds for the founding of the nation-states of Germany and Italy by starting the process of consolidating city-states, kingdoms and principalities. At the end of the war, Denmark was forced to cede Norway to Sweden mainly as a compensation for the loss of Finland which the other coalition members agreed to, but because Norway had signed its own constitution on 17 May 1814 Sweden initiated the Swedish–Norwegian War (1814). The war was a short one taking place between 26 July – 14 August 1814 and was a Swedish victory that put Norway into a personal union with Sweden. The union was peacefully dissolved in 1905. The United Kingdom of the Netherlands created as a buffer state against France dissolved rapidly with the independence of Belgium in 1830.
Sources: en.wikipedia.org
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.
Hydrolysis of peptide bonds and deamidation of arginine and proline residues are the main degradation routes. Alkaline pH and higher temperatures accelerate both processes. Buffered, near-neutral solutions stored cold generally degrade more slowly than unbuffered ones.
Reverse-phase chromatography gives the clearest single view of related impurities and truncated sequences. Mass spectrometry then confirms that the main peak carries the expected mass. Neither test detects enantiomeric impurities, which require a separate chiral assay.
Reports describe modulation of GABA signalling, changes in monoamine turnover and effects on neurotrophic factor expression. These observations come mainly from animal and cell studies. A single unifying mechanism has not been demonstrated.