heptapeptide is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2026-08-01. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Principal proposed target | GABA-A receptor complex | Hypothesis derived mainly from animal pharmacology |
| Common behavioral assay | Elevated plus maze | Rodent test for anxiety-like behavior |
| Reported molecular marker | Hippocampal BDNF expression | Measured by immunoassay or mRNA quantification |
| Typical dosing route | Intranasal | Chosen to reduce first-pass metabolism |
| Reported plasma half-life | Minutes | Based on limited peptide stability data |
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.
Diagnosis of gonococcal and other neisserian infections: amplification of specific N. gonorrhoeae DNA or RNA sequences for detection. Diagnosis of urogenital C. trachomatis infections Detection of Mycobacterium tuberculosis Detection of HIV RNA or DNA Detection of zoonotic coronaviruses Diagnostic test for SARS-CoV-2 Detection of antibiotic resistant bacteria following antibiotic treatment
Although the term was coined in the late 1980s one of the first retroactively recognized examples of a killer application is the VisiCalc spreadsheet, released in 1979 for the Apple II. Because it was not released for other computers for 12 months, people spent US$100 (equivalent to $400 in 2025) for the software first, then $2,000 to $10,000 (equivalent to $9,000 to $44,000) on the requisite Apple II. Byte wrote in 1980, "VisiCalc is the first program available on a microcomputer that has been responsible for sales of entire systems", and Creative Computing's VisiCalc review is subtitled "reason enough for owning a computer". Others also chose to develop software, such as EasyWriter, for the Apple II first because of its higher sales, helping Apple defeat rivals Commodore International and Tandy Corporation. The co-creator of WordStar, Seymour Rubinstein, argued that the honor of the first killer app should go to that popular word processor, given that it came out a year before VisiCalc and that it gave a reason for people to buy a computer. However, whereas WordStar could be considered an incremental improvement (albeit a large one) over smart typewriters like the IBM Electronic Selectric Composer, VisiCalc, with its ability to instantly recalculate rows and columns, introduced an entirely new paradigm and capability unavailable on larger computers. Lotus 1-2-3 similarly benefited sales of the IBM PC. Noting that computer purchasers did not want PC compatibility as much as compatibility with certain PC software, InfoWorld suggested "let's tell it like it is.
Duterte has been linked by human rights groups such as Amnesty International and Human Rights Watch to extrajudicial killings of over 1,400 alleged criminals and street children by vigilante death squads. In the April 2009 UN General Assembly of the Human Rights Council, the UN report (Eleventh Session Agenda item 3, par 21) said, "The Mayor of Davao City has done nothing to prevent these killings, and his public comments suggest that he is, in fact, supportive." Duterte emphasized that the concept of human rights for criminals is Western and should not apply to the Philippines; he further challenged human rights officials to file a case against him if they could provide evidence of his links with vigilante groups.
==== Incorporation of tertiary mechanisms ==== Many phototherapeutic agents that display both PD and PT activity come with added effects, such as antibiotic metal ions, physical antibiotic mechanisms, or peroxidase-like activity. These added effects further increase antibiotic activity, often demonstrating broadband activity with 99% cell death or above regardless of strain or drug resistance.
=== Muscle spindles === Poppele and Bowman used linear system theory to model mammalian muscle spindles Ia and II afferents. They recorded from a set of muscle spindles devoid of fusimotor action, measured their response to a series of sinusoidal and step function stretches, and fit a transfer function to the spike rate. They found that the following Laplace transfer function describes the firing rate responses of the primary sensory fibers for a change in length:
Sources: en.wikipedia.org
2-Amino-3-carboxymuconic semialdehyde is an intermediate in the metabolism of tryptophan in the kynurenine pathway. Quinolinic acid is a neurotoxin formed nonenzymatically from 2-amino-3-carboxymuconic semialdehyde in mammalian tissues. 2-Amino-3-carboxymuconic semialdehyde is enzymatically converted to picolinic acid via 2-aminomuconic semialdehyde.
=== Fourth Republic === June 27, 1947: Decree creating the medical code of ethics; it includes provisions on therapeutic abortion. November 1947: Germaine Poinso-Chapuis becomes France's first female minister, for Public Health and Population; the second female minister in the country will be Simone Veil in 1974. November 5, 1947: Decree implementing the April 24, 1946, law establishing a sanitary and social registry of prostitution. September 1, 1948: Law modifying and codifying legislation on relations between landlords and tenants or occupants of residential or professional premises and establishing housing allowances. August 11, 1950: Law publishing ILO Convention No. 3 (adopted on November 29, 1919) and authorizing its ratification; this convention concerns the employment of pregnant and newly delivered women. October 15, 1951: Decree on the status of female military personnel. December 10, 1952: Law authorizing the ratification of ILO Convention No. 100, concerning "equal remuneration for men and women for work of equal value." May 17, 1954: Decree on the family record book: contents and definitions of the records and extracts to be included. August 6, 1955: Law setting the supplementary budget for agricultural family benefits for fiscal years 1955 and 1956; notably establishes a "housewife allowance," granted to the "head of household" under certain conditions. November 28, 1955: Decree on the medical code of ethics, modifying the previous one.
Extracting oil (or "bitumen") from oil/tar sand and oil shale deposits requires mining the sand or shale and heating it in a vessel or retort, or using "in-situ" methods of injecting heated liquids into the deposit and then pumping the liquid back out saturated with oil.
==== Formation of the state (1945–1946) ==== After the Second World War most of Northwest Germany lay within the British Zone of Occupation. On 23 August 1946, the British Military Government issued Ordinance No. 46 "Concerning the dissolution of the provinces of the former state of Prussia in the British Zone and their reconstitution as independent states", which initially established the State of Hanover on the territory of the former Prussian Province of Hanover. Its minister president, Hinrich Wilhelm Kopf, had already suggested in June 1945 the formation of a state of Lower Saxony, that was to include the largest possible region in the middle of the British Zone. In addition to the regions that actually became Lower Saxony subsequently, Kopf asked, in a memorandum dated April 1946, for the inclusion of the former Prussian district of Minden-Ravensberg (i.e. the Westphalian city of Bielefeld as well as the Westphalian districts of Minden, Lübbecke, Bielefeld, Herford and Halle), the district of Tecklenburg and the state of Lippe. Kopf's plan was ultimately based on a draft for the reform of the German Empire from the late 1920s by Georg Schnath and Kurt Brüning. The strong Welf connotations of this draft, according to Thomas Vogtherr, did not simplify the development of a Lower Saxon identity after 1946.
Sources: en.wikipedia.org
=== Nutrition-related factors === There have been multiple attempts to uncover a link between various nutritional deficiencies such as vitamin D and folate and autism risk. Although there have been many studies on the role of vitamin D in the development of autism, the majority of them are limited by their inability to assess the deficiency prior to an autism diagnosis. A meta-analysis on the association between vitamin D and autism found that individuals with autism had significantly low levels of serum 25-hydroxy vitamin D than those without autism. Another analysis showed significant differences in levels of zinc between individuals with and without autism. Although studies showed significant differences protein intake and calcium in individuals with autism, the results were limited by their imprecision, inconsistency, and indirect nature. Additionally, low levels of 5-methyltetrahydrofolate (5-MTHF) in the brain can result in cerebral folate deficiency (CFD) which has been shown to be associated with autism.
PAP leaders believed that Singapore's future lay with Malaya, due to strong ties between the two. It was thought that reuniting with Malaya would benefit the economy by creating a common market, alleviating ongoing unemployment woes in Singapore. However, a sizeable left-wing faction of the PAP was strongly opposed to the merger, fearing a loss of influence, and hence formed the Barisan Sosialis, after being kicked out from the PAP. The ruling party of Malaya, United Malays National Organisation (UMNO), was staunchly anti-communist, and it was suspected UMNO would support the non-communist factions of PAP. UMNO, initially sceptical of the idea of a merger due to distrust of the PAP government and concern that the large ethnic Chinese population in Singapore would alter the racial balance in Malaya on which their political power base depended, became supportive of the idea of the merger due to joint fear of a communist takeover. On 27 May 1961, Malaya's prime minister, Tunku Abdul Rahman, made a surprise proposal for a new Federation called Malaysia, which would unite the current and former British possessions in the region: the Federation of Malaya, Singapore, Brunei, North Borneo, and Sarawak. UMNO leaders believed that the additional Malay population in the Bornean territories would balance Singapore's Chinese population. The British government, for its part, believed that the merger would prevent Singapore from becoming a haven for communism. To obtain a mandate for a merger, the PAP held a referendum on the merger.
==== Revisionism in the 21st century ==== Despite the overall focus away from the Orthodox vs. Revisionist debates there have been new revisionist works that have emerged in the 21st century. One such example is Norman Naimark's 2019 Stalin and the Fate of Europe: The Postwar Struggle for Sovereignty.. Another work arguing that Stalin in fact sought to avoid the Cold War is the 2006 Stalin's Wars: From World War to Cold War, 1939-1953 by Geoffrey Roberts.
Sources: en.wikipedia.org
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.
Behavioral endpoints include time spent in open arms of the elevated plus maze and avoidance latencies. Biochemical endpoints include BDNF concentration, cytokine levels, and monoamine metabolite ratios in brain tissue.
Most published studies are small, originate from a limited number of laboratories, and lack independent replication. Dose-response relationships, measured brain exposure, and long-term outcomes are not well characterized.
Selank is a synthetic heptapeptide designed as a stabilized analog of the natural tetrapeptide tuftsin. It has been investigated mainly for anxiolytic and cognitive effects. It is not an approved pharmaceutical in most countries.