tuftsin 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.
Last reviewed on 2025-11-06. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Pharmacokinetic data are limited. Like most short peptides, Selank is vulnerable to plasma and tissue peptidases, and its measured half-life in circulation is short, on a minutes scale. The Pro-Gly-Pro tail slows this degradation but does not eliminate it. Intranasal administration is the route described in most reports, with absorption through the nasal mucosa and a hypothesized path into the central nervous system that avoids the blood-brain barrier. Direct measurements of human brain exposure are unavailable, so distribution claims rest on inference from animal work.
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.
The compound was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences during the 1980s and 1990s. The stated design goal was to retain the immunomodulatory and central nervous system activity attributed to tuftsin while improving resistance to enzymatic breakdown. Adding a proline-rich tail to the short parent peptide was a deliberate strategy, because proline residues restrict the conformations available to many peptidases. The same laboratory produced Semax, an ACTH fragment analog, and both compounds were developed in parallel as short, enzymatically stabilized peptides intended for intranasal use.
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.
| 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 |
Lyophilized material is generally stable for extended periods when kept dry at or below minus twenty degrees Celsius. Working solutions are less stable, and common practice is to aliquot and freeze them so that repeated freeze-thaw cycles are avoided. Aqueous solutions are sensitive to pH extremes and to microbial growth, so short-term storage at refrigerator temperature is typical. Oxidation and hydrolysis are the principal degradation routes. Reconstitution with sterile water or a mild buffer is standard, and solutions should be protected from light.
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.
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.
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.
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.
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.
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.
Characterization of Selank in laboratory settings relies on standard peptide analytical techniques. Reverse-phase high-performance liquid chromatography separates the peptide from related impurities and degradation products, while mass spectrometry confirms molecular identity through accurate mass measurement. Amino acid analysis and peptide sequencing verify the primary structure when reference material is unavailable. Because Selank is a short chain, fragmentation-based analysis produces a diagnostic ion pattern that supports confident identification.
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.
Human Growth Hormone Fragment 176–191 (hGH frag 176–191) is a peptide fragment of human growth hormone. It has erroneously been presented as a lipolytic peptide fragment based on extrapolations of clinical data pertaining to AOD9604, a modified form of hGH frag 176–191. In contrast to AOD9604, hGH frag 176–191 has not been studied in humans.
=== Interbellum (1918–1939) === Elements of the Army operated around Mary, Turkmenistan in 1918–19. See Malleson mission and Entente intervention in the Russian Civil War. The army then took part in the Third Anglo-Afghan War of 1919. In the aftermath of the First World War, the Indian Territorial Force and Auxiliary Force (India) were created in the 1920s. The Indian Territorial Force was a part-time, paid, all-volunteer organisation within the army. Its units were primarily made up of European officers and Indian other ranks. The ITF was created by the Indian Territorial Force Act 1920 to replace the Indian section of the Indian Defence Force. It was an all-volunteer force modelled after the British Territorial Army. The European parallel to the ITF was the Auxiliary Force (India). After the First World War the British started the process of Indianisation, by which Indians were promoted into higher officer ranks. In a 1923 census, the British Indian Army consisted of 64,669 British-born soldiers and officers, with 187,432 Indian-born soldiers in comparison. Indian cadets were sent to study in Great Britain at the Royal Military College, Sandhurst, and were given full commissions as King's Commissioned Indian Officers. The KCIOs were equivalent in every way to British commissioned officers and had full authority over British troops (unlike VCOs). Some KCIOs were attached to British Army units for a part of their careers.
Infections with carbapenem-resistant Klebsiella pneumoniae were associated with organ/stem cell transplantation, mechanical ventilation, exposure to antimicrobials, and overall longer length of stay in hospitals. People most likely to acquire carbapenem-resistant bacteria are those already receiving medical attention. In a study carried out at Sheba medical center, there was a trend toward worse Charleson Comorbidity scores in patients who acquired CRKP during ICU stay. Those at highest risk are patients receiving an organ or stem cell implantation, use of mechanical ventilation, or have to have an extended stay in the hospital along with exposure to antimicrobials. A study performed in Singapore, on the acquisition of ertapenem-resistant Enterobacteriaceae to the acquisition of CRE. revealed that exposure to antibiotics, especially fluoroquinolones and previous hospitalization dramatically increased the risk of acquisition carbapenem-resistant bacteria. This study found that carbapenem-resistant acquisition has a significantly higher mortality rate and poorer clinical response compared to that of the ertapenem-resistance acquisition. Bacteruria (also known as urinary tract infection) caused by CRKp and CSKp have similar risk factors. These include prior antibiotic use, admittance to an ICU, use of a permanent urinary catheter, and previous invasive procedures or operations.
Sources: en.wikipedia.org
MDMA has become widely known as ecstasy (shortened "E", "X", or "XTC"), usually referring to its tablet form, although this term may also include the presence of possible adulterants or diluents. The UK term "mandy" and the US term "molly" colloquially refer to MDMA in a crystalline powder form that is thought to be free of adulterants. MDMA is also sold in the form of the hydrochloride salt, either as loose crystals or in gelcaps. MDMA tablets can sometimes be found in a shaped form that may depict characters from popular culture. These are sometimes collectively referred to as "fun tablets". Partly due to the global supply shortage of sassafras oil—a problem largely assuaged by use of improved or alternative modern methods of synthesis—the purity of substances sold as molly have been found to vary widely. Some of these substances contain methylone, ethylone, MDPV, mephedrone, or any other of the group of compounds commonly known as bath salts, in addition to, or in place of, MDMA. Powdered MDMA ranges from pure MDMA to crushed tablets with 30–40% purity. MDMA tablets typically have low purity due to bulking agents that are added to dilute the drug and increase profits (notably lactose) and binding agents. Tablets sold as ecstasy sometimes contain 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxyethylamphetamine (MDEA), other amphetamine derivatives, caffeine, opiates, or painkillers. Some tablets contain little or no MDMA. The proportion of seized ecstasy tablets with MDMA-like impurities has varied annually and by country.
=== Der Schrecken Gottes: Attar, Hiob und die metaphysische Revolte (postdoctoral thesis 2005) === It is precisely this question that Kermani addresses in his postdoctoral thesis Der Schrecken Gottes: Attar, Hiob und die metaphysische Revolte (The Terror of God: Attar, Job and the Metaphysical Revolt). In this book, Kermani takes up the basic idea of practical-authentic theodicy, which consists in demanding God's justice against the injustice of the world, that is, in Kantian terms, postulating the reality of God and thus God's authentic self-justification without attributing to God the wish to achieve this doctrinally himself. This postulate necessarily includes protest against suffering, which is expressed in quarreling with God and accusing God. Even though wrestling with God is largely frowned upon in Islamic orthodoxy, as it is in Christian orthodoxy, the Islamic mystical literature cited by Kermani, as well as the Book of Job, reveal ways of wrestling with God that are nourished by devotion to God and can accompany the indispensable, postulative discourse on God. For Kermani, the most significant testimony to this wrestling is The Book of Suffering by the Persian mystical poet Attar (1145–1221), a text that shows how in the Islamic tradition it is possible to argue and quarrel with God. From the perspective of the fools whom Attar references, God appears both as the persecutor and tormentor of humankind and yet also as its last hope.
GLP requires not only that the methods of safety tests be transparent, but that they be so detailed that a different laboratory using it will get the same result. Considering that Japan, Netherlands, US and others had at same time as GLP begun requiring demonstrations of safety before chemicals gained access markets; the Organisation for Economic Cooperation & Development decided that multinational companies needed globally uniform regulation of chemicals, such that a toxicity test performed in one country could be accepted by another. OECD was thus happy to add the new USA GLP requirement into their new, globally-required test methods, called ‘OECD Test Guidelines’ (see below OECD section).
Unlike standard SPPS (which is limited to 50 amino acid residue) NCL allows the construction of large glycopeptides. However the strategy is limited by the fact that it requires a cysteine residue at N-terminus, an amino acid residue that is rare in nature. However this problem has partly been address by the selective desulfurization of the cysteine residue to an alanine.
Sources: en.wikipedia.org
Ertapenem, sold under the brand name Invanz, is a carbapenem antibiotic medication used for the treatment of infections of the abdomen, the lungs, the upper part of the female reproductive system, and the diabetic foot. The most common side effects include diarrhoea, nausea, headache, and problems around the area where the medicine is infused. It can significantly reduce the concentrations of valproic acid, an anti-seizure medication, in the blood to the point where it loses its effectiveness. Ertapenem was approved for medical use in the United States in November 2001, and in the European Union in April 2002. It is marketed by Merck.
== Stability == In 2016, laboratory research established and compared the radiosensitivity of three organic food colorants including curcumin, carmine, and annatto to create data to be used for application whenever food products containing these food colors were to undergo the radiation process. The researchers used spectrophotometry and capillary electrophoresis to establish radiosensitivity of the three organic food colorants. Carmine samples were quite stable against radiation treatment, annatto showed limited stability, and curcumin was found to be unstable, particularly when diluted.
Michael T. Longaker is an American medical researcher and board-certified plastic surgeon. He has been a member of the Stanford Diabetes Research Center since 2018. He is the Deane P. and Louise Mitchell Professor for Plastic and Reconstructive Surgery, and by courtesy a Professor of Materials Science and Engineering. He is a co-founder of the medical research venture capital fund TauTona Group, as well as of biotechnology companies Arresto Biosciences and Neodyne Biosciences.
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.
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.