If you have been reading about TKPRPGP and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2026-03-16. Numbers and descriptions here follow the published literature rather than marketing material.
Clinical evidence comes mainly from small studies conducted in Russia, several of which were open-label or lacked robust blinding. Reported outcomes include lower anxiety scores, changes in attention measures, and effects on asthenic states following illness. Sample sizes are typically in the tens of participants, and independent replication outside the region is scarce. Reviews published in English generally note the limited methodological quality of the underlying trials. Whether the compound produces clinically meaningful effects under rigorous conditions remains unresolved.
Proposed mechanisms center on modulation of the GABA system, but no single molecular target has been confirmed. Rodent studies report changes in GABA-A receptor expression and in the turnover of serotonin, dopamine, and norepinephrine in several brain regions. Increases in brain-derived neurotrophic factor and its receptor have also been described after repeated administration. These findings come largely from animal models, and the degree to which they describe human neurochemistry remains an open question. The mechanism is best characterized as multi-system and not fully resolved.
Development took place at the Institute of Molecular Genetics of the Russian Academy of Sciences, where a series of short peptides were designed in the 1980s and 1990s. Selank was selected from variants of tuftsin that showed resistance to plasma peptidases. Russian regulatory approval covers it as an anxiolytic agent given intranasally. Outside that market the compound is normally handled as a research chemical rather than a medicine, and no widely recognised international pharmacopoeial monograph exists. The name Selank is a coined trade designation rather than a systematic chemical name.
Enzymatic stability motivates the extra three residues at the carboxyl end. Native tuftsin is cleaved quickly by circulating aminopeptidases and carboxypeptidases, which limits its duration of action and its usefulness as a tool compound. Extending the chain with proline-rich segments is a common design tactic because proline constrains the backbone and slows proteolysis. The same Pro-Gly-Pro motif appears in other Russian-developed peptides of the era. Whether the full seven-residue chain is required for activity, or whether it acts mainly as a prodrug releasing tuftsin, remains unresolved.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. Its four N-terminal residues reproduce tuftsin, a tetrapeptide fragment of the immunoglobulin heavy chain, while the C-terminal Pro-Gly-Pro extension is a synthetic addition. The peptide has a molecular mass near 752 daltons and carries a net positive charge at physiological pH because of the arginine and lysine side chains. Published indexes list it under the name Selank and the sequence abbreviation TKPRPGP. Solid-phase peptide synthesis is the standard production route for research quantities.
| Property | Value | Notes |
|---|---|---|
| Route studied | Intranasal | Predominant route in published reports |
| Circulation stability | Short, minutes scale | Peptidases cleave it; the tail slows the process |
| Analytical method | RP-HPLC with mass spectrometry | Used for identity and purity assessment |
| Reported outcome domains | Anxiety and cognitive measures | Derived from small, mostly regional trials |
| Regulatory status | Marketed in Russia | Availability outside that market is limited |
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.
Dry powder is normally held at -20 degrees Celsius or lower, in a sealed container with desiccant and protection from light. Reconstituted solutions are usually kept at 2 to 8 degrees Celsius for short periods and frozen for longer ones. Proline residues at several positions are generally associated with some resistance to peptidase attack, but chemical stability still declines at neutral to alkaline pH and at elevated temperature. Exact shelf-life figures are product-specific and are not standardised across suppliers.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography, with mass spectrometry used to confirm molecular mass and sequence information. Amino acid analysis and peptide mapping may supplement these methods. Certified reference standards are scarce, and many commercial lots are sold as research chemicals without a pharmacopoeial monograph. Regulatory treatment differs by country: Selank is a registered prescription medicine in Russia, while in the European Union and the United States it is not an approved drug and may fall under research-chemical or unapproved-product frameworks.
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.
=== True protein === In at least one segment of the food industry, the dairy industry, some countries (at least the U.S., Australia, France and Hungary) have adopted "true protein" measurement, as opposed to crude protein measurement, as the standard for payment and testing: "True protein is a measure of only the proteins in milk, whereas crude protein is a measure of all sources of nitrogen and includes nonprotein nitrogen, such as urea, which has no food value to humans. ... Current milk-testing equipment measures peptide bonds, a direct measure of true protein." Measuring peptide bonds in grains has also been put into practice in several countries including Canada, the UK, Australia, Russia and Argentina where near-infrared reflectance (NIR) technology, a type of infrared spectroscopy is used. The more traditional approach to true protein analysis is amino acid analysis. Data from such analysis has additional nutritional meaning, as humans and other animals have specific requirements for essential amino acids. The Food and Agriculture Organization of the United Nations (FAO) recommends that only amino acid analysis be used to determine protein in, inter alia, foods used as the sole source of nourishment, such as infant formula, but also provides: "When data on amino acids analyses are not available, determination of protein based on total N content by Kjeldahl (AOAC, 2000) or similar method ...
After stops in Helsinki and Moscow to smooth out Iraqi demands for a Middle-Eastern peace conference with the Soviet Union, Baker traveled to Syria to discuss its role with President Hafez Assad. Assad had a personal enmity towards Saddam, as "Saddam had been trying to kill him [Assad] for years." Harboring this animosity and impressed with Baker's initiative to visit Damascus (relations had been severed since the 1983 bombing of US barracks), Assad agreed to pledge up to 100,000 Syrian troops to the coalition. This was a vital step in ensuring Arab states were represented in the coalition. In exchange, Washington gave al-Assad the green light to wipe out forces opposing Syria's rule in Lebanon and arranged for weapons valued at a billion dollars to be provided to Syria, mostly through Gulf states. In exchange for Iran's support for the US-led intervention, the US promised Iran to end US opposition to World Bank loans to Iran. On the day before the coalition ground invasion, the World Bank gave Iran the first loan of $250m. Baker flew to Rome for a meeting with the Italians in which he was promised the use of military equipment, before journeying to Germany to meet with American ally Chancellor Kohl. Although Germany's constitution (brokered by the US) prohibited military involvement outside Germany's borders, Kohl committed a two billion dollar contribution to the war effort, and further economic and military support of coalition ally Turkey, and the transportation of Egyptian soldiers and ships to the Gulf.
Cannabinol (CBN) is a mildly psychoactive phytocannabinoid that acts as a low affinity partial agonist at the CB1 and CB2 receptors of the endocannabinoid system (ECS). Although CBN shares the same mechanism of action as other phytocannabinoids such as tetrahydrocannabinol (THC), it has a lower affinity for CB1 receptors, meaning that much higher doses of CBN are required in order to experience intoxicating effects. It was the first cannabinoid to be isolated from plants of genus Cannabis and was discovered in 1896.
Dysphoric milk ejection reflex (D-MER) is a condition in which breastfeeding women develop negative emotions that begin just before the milk letdown reflex and last less than a few minutes. It may recur with every letdown, including unexpected letdowns when the baby is not feeding. It presents as an emotional reaction but may also produce physical feelings such as nausea. It is different from postpartum depression and other known psychological conditions. A 2019 study reported a prevalence rate of 9.1%. As of 2021, very little research has been done, and many health care providers and lactation practitioners remain barely able to recognize the syndrome. An October 2021 review of literature published to that date suggested that the lack of up-to-date information "makes it necessary to educate mothers because educated mothers are usually better at handling postpartum situations if they are prepared in advance." There is as yet no medication to treat the symptoms although women have reported that they have found it of benefit to learn that they are not alone and that the symptoms were not "just in their head".
Sources: en.wikipedia.org
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Wound bed preparation (WBP) is a systematic approach to wound management by identifying and removing barriers to healing. The concept was originally developed in plastic surgery. It includes wound assessment, debridement, moisture balance, bacterial balance, and wound cleaning.
Boston Pizza (branded as Boston's Restaurant & Sports Bar outside of Canada) has franchised 396 restaurants in North America. Boston Pizza International Inc. was Canada's number one casual dining brand with more than 340 restaurants in Canada and system-wide sales of $831 million in 2008. Annually, Boston Pizza serves more than 40 million guests. The first Boston Pizza location was opened in Edmonton, Alberta in 1964 by Gus Agioritis under the name "Boston Pizza and Spaghetti House". It took 32 years to open its first 100 locations, and eight years for the next 100. The current owners of the restaurant chain, Jim Treliving and George Melville, purchased the company in 1983, 15 years after Treliving bought his first franchise, and 10 years after he first partnered with Melville. Store sales growth has averaged 6.3% for the last decade compared to the industry average of 2.2%.
=== Mold growth === Penicillium roqueforti and Penicillium glaucum are both molds that require the presence of oxygen to grow. Therefore, initial fermentation of the cheese is done by lactic acid bacteria. The lactic acid bacteria, however, are killed by the low pH and the secondary fermenters, Penicillium roqueforti, take over and break the lactic acid down, maintaining a pH in the aged cheese above 6.0. As the pH rises again from the loss of lactic acid, the enzymes in the molds responsible for lipolysis and proteolysis are more active and can continue to ferment the cheese because they are optimal at a pH of 6.0. Penicillium roqueforti creates the characteristic blue veins in blue cheese after the aged curds have been pierced, forming air tunnels in the cheese. When given oxygen, the mold is able to grow along the surface of the curd-air interface. The veins along the blue cheese are also responsible for the aroma of blue cheese itself. In fact, one type of bacteria in blue cheese, Brevibacterium linens, is the same bacteria responsible for foot and body odor. B. linens was previously thought to give cheeses their distinct orangish pigmentation, but studies show this not to be the case and blue cheese is an example of the lack of that orange pigmentation. In pressing the cheese, the curds are not tightly packed in order to allow for air gaps between them. After piercing, the mold can also grow in between the curds.
=== Modified Miller–Urey experiments === Much work has been done since the 1950s toward understanding how Miller–Urey chemistry behaves in various environmental settings. Different atmospheric compositions. In 1983, testing different atmospheric compositions, Miller and another researcher repeated experiments with varying proportions of H2, H2O, N2, CO2 or CH4, and sometimes NH3. They found that the presence or absence of NH3 in the mixture did not significantly impact amino acid yield, as NH3 was generated from N2 during the spark discharge. Additionally, CH4 proved to be one of the most important atmospheric ingredients for high yields, likely due to its role in HCN formation. Much lower yields were obtained with more oxidized carbon species in place of CH4, but similar yields could be reached with a high H2/CO2 ratio. Thus, Miller–Urey reactions work in atmospheres of other compositions as well, depending on the ratio of reducing and oxidizing gases. Role of nitrites and calcium carbonate. More recently, Jeffrey Bada and H. James Cleaves, graduate students of Miller, hypothesized that the production of nitrites, which destroy amino acids, in CO2 and N2-rich atmospheres may explain low amino acids yields. In a Miller–Urey setup with a less-reducing (CO2 + N2 + H2O) atmosphere, when they added calcium carbonate to buffer the aqueous solution and ascorbic acid to inhibit oxidation, yields of amino acids greatly increased, demonstrating that amino acids can still be formed in more neutral atmospheres under the right geochemical conditions.
Sources: en.wikipedia.org
Reports describe effects on GABA-A receptor expression, monoamine turnover, and neurotrophic factor levels. These are proposed mechanisms drawn mainly from animal models. No single molecular target has been established.
Intranasal delivery is the route described in most published work. It is used because the peptide is degraded quickly once it reaches circulation. Direct evidence of brain penetration in humans is lacking.
Most trials are small, regionally concentrated, and often lack rigorous blinding or placebo control. Independent replication is limited. Reviews in English generally rate the evidence as preliminary.
Selank is a seven-amino-acid peptide built from the tuftsin sequence plus a Pro-Gly-Pro tail. It is produced by chemical synthesis rather than extracted from a natural source. The free peptide is usually supplied as a lyophilised powder or in an aqueous formulation.