tuftsin comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2025-08-26. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
The primary structure of Selank is Thr-Lys-Pro-Arg-Pro-Gly-Pro, corresponding to the molecular formula C33H57N11O9 and a monoisotopic mass of roughly 751.9 daltons. The N-terminal threonine and the arginine residue in the fourth position are shared with tuftsin, which carries the sequence Thr-Lys-Pro-Arg. The three additional residues at the C-terminus, Pro-Gly-Pro, extend the chain and are associated with greater resistance to enzymatic degradation. This extension also separates Selank from the shorter parent peptide.
Lyophilized Selank, the dry powder form, is generally stored frozen at minus 20 degrees Celsius or colder for long-term keeping. The solid is hygroscopic and should stay sealed, dry, and protected from light. Once dissolved, the peptide is less stable and is usually held refrigerated at 2 to 8 degrees Celsius for short periods. Repeated freezing and thawing is avoided because it can promote aggregation and loss of activity. Buffers and pH choice also affect how long a solution remains usable.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic heptapeptide | Stabilized analog of tuftsin |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form: TKPRPGP |
| Molecular formula | C33H57N11O9 | Monoisotopic mass about 751.9 Da |
| Appearance | White to off-white powder | Typically supplied as lyophilized solid |
| Solubility | Freely soluble in water | Also soluble in common polar solvents |
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.
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.
creatine Thus, the two substrates of this enzyme are creatinine and H2O, whereas its product is creatine. Creatininase is a member of the urease-related amidohydrolases, the family of hydrolases, those acting on carbon-nitrogen bonds other than peptide bonds, specifically in cyclic amides. The systematic name of this enzyme class is creatinine amidohydrolase. This enzyme is also called creatinine hydrolase. This enzyme participates in arginine and proline metabolism.
=== Additives and flavoring === To achieve a buttery profile in cultured lines, manufacturers can add small amounts of citrate-fermenting lactococci or Leuconostoc bacterial strains to the starter mix to produce diacetyl. Producers typically maintain a diacetyl-to-acetaldehyde ratio of 3–5 to 1; deviations from this ratio alter the sensory profile, with lower ratios yielding notes described as grassy and higher ratios yielding a sharper taste. Titanium dioxide (E171) is added to some commercial brands to act as an opaque whitening agent. While permitted up to 1% of total volume by weight in the United States by the Food and Drug Administration (FDA), its global usage has declined due to shifting regional regulations on nanoparticle technology in food ingredients. Following a 2021 assessment by the European Food Safety Authority (EFSA) highlighting unresolved genotoxicity and nanoparticle accumulation concerns, the European Union implemented a full ban on E171 in food products starting in August 2022. In contrast, the United Kingdom represents a distinct post-Brexit regulatory divergence. The UK Food Standards Agency (FSA), alongside the Committee on Toxicity (COT) and the Committee on Mutagenicity (COM), reviewed the EFSA evidence and concluded that the dietary risk of genotoxicity from food-grade E171 was low. Consequently, titanium dioxide remains a permitted food additive in Great Britain under retained domestic food law.
MRI requires a magnetic field that is both strong and uniform to a few parts per million across the scan volume. The field strength of the magnet is measured in teslas – and while the majority of systems operate at 1.5 T, commercial systems are available between 0.2 and 7 T. 3T MRI systems, also called 3 Tesla MRIs, have stronger magnets than 1.5 systems and are considered better for images of organs and soft tissue. Whole-body MRI systems for research applications operate in e.g. 9.4T, 10.5T, 11.7T. Even higher field whole-body MRI systems e.g. 14 T and beyond are in conceptual proposal or in engineering design. Most clinical magnets are superconducting magnets, which require liquid helium to keep them at low temperatures. Lower field strengths can be achieved with permanent magnets, which are often used in "open" MRI scanners for claustrophobic patients. Lower field strengths are also used in a portable MRI scanner approved by the FDA in 2020. Recently, MRI has been demonstrated also at ultra-low fields, i.e., in the microtesla-to-millitesla range, where sufficient signal quality is made possible by prepolarization (on the order of 10–100 mT) and by measuring the Larmor precession fields at about 100 microtesla with highly sensitive superconducting quantum interference devices (SQUIDs).
The Rhodesian army continued its "mobile counter-offensive" strategy of holding key positions ("vital asset ground") while carrying out raids into the no-go areas and into neighbouring countries. While often extraordinarily successful in inflicting heavy guerrilla casualties, such raids also on occasion failed to achieve their objectives. In April 1979 special forces carried out a raid on Joshua Nkomo's residence in Lusaka, Zambia, with the stated intention of assassinating him. Nkomo and his family left hastily a few hours before the raid – having clearly been warned that the raid was coming. In 1979, some special forces units were accused of using counterinsurgent operations as cover for ivory poaching and smuggling. Colonel Reid-Daly (commander of the Selous Scouts) discovered that his phone was bugged and after challenging a superior officer on this issue was court martialled for insubordination. He received the lightest sentence possible, a caution, but he continued to fight his conviction and eventually resigned his commission and left the Army. By 1978–1979, up to 70% of the regular army was composed of black soldiers (though both the army and police reserves remained overwhelmingly white). By 1979 there were also 30 black commissioned officers in the regular army. While there was never any suggestion of disloyalty among the soldiers from predominantly black units (in particular within the Selous Scouts or the Rhodesian African Rifles – RAR), some argue that, by the time of the 1980 election, many of the RAR soldiers voted for Robert Mugabe.
Sources: en.wikipedia.org
=== Plasma or whole blood === In this article, all values (except the ones listed below) denote blood plasma concentration, which is approximately 60–100% larger than the actual blood concentration if the amount inside red blood cells (RBCs) is negligible. The precise factor depends on hematocrit as well as amount inside RBCs. Exceptions are mainly those values that denote total blood concentration, and in this article they are:
Corticotropic cells of the anterior pituitary gland Melanotropic cells of the intermediate lobe of the pituitary gland Neurons of the arcuate nucleus (infundibular nucleus) in the hypothalamus Smaller populations of neurons in the dorsomedial hypothalamus and brainstem Melanocytes in the skin.
On 5 March 2013, Olofsson submitted his 24-page application for a new trial to the Supreme Court, where he, among other things, withdrew his involvement. The application was rejected in April 2013. As early as 2010, Olofsson applied for relocation to Belgium in the hope of a shorter sentence. The move from Kumla Prison in Sweden was delayed for several years and did not take place until the end of 2016 - then against his will - after Swedish and Belgian representatives agreed that he would be imprisoned for at least as long in Vorst Prison in Belgium. In February 2017, Olofsson turned 70 years old and was granted new Swedish citizenship. In October 2017, he was rejected in a Belgian court on his application for an ankle monitor. Olofsson demanded relocation back to Sweden. Belgium granted the application but in November 2017 Sweden rejected it.
=== Light chain (AL-CM) === This relatively rare form of cardiac amyloidosis occurs in an estimated six to ten cases per 1,000,000 people. This sub- type usually affects males over the age of 60 and is rapidly progressive. Pathogenesis of this form is due to the aggregation of immunoglobulin lambda light chains. These chains are created by an abnormal expansion of plasma cells. Over time, these light chains deposit into the interstitial tissue within the myocardium. Diagnostic tests includes serum and urine electrophoresis, laboratory testing for the determination of elevated levels of troponin and BNP, and ECGs showing low QRS voltages.
=== Pharmacokinetics === Metabolism of myristicin yields 3-methoxycatechol and enzymatically forms 5-allyl-1-methoxy-2,3-dihydroxybenzene (oxidation of the methylenedioxy group). Myristicin is also transformed into demethylenylmyristicin, dihydroxymyristicin, and elemicin is transformed into O-demethylelemicin, O-demethyldihydroxyelemicin, and safrole. There has been speculation that myristicin might be converted into the psychedelic MMDA, but this has not been demonstrated in humans. However, two nitrogen-containing metabolites of myristicin have been identified in the urine of rats and guinea pigs following oral or intraperitoneal administration. The major basic ninhydrin-positive urinary metabolite of myristicin in the rat is 3-piperidyl-1-(3′methoxy-4′,5′-methylenedioxyphenyl)-1-propanone, while the major basic ninhydrin-positive urinary metabolite of the guinea pig is 3-pyrrolidinyl-1-(3′methoxy-4′,5′-methylenedioxyphenyl)-1-propanone. Equivalent nitrogen-containing metabolites have also been identified for safrole and elemicin, including the dimethylamine, piperidine and pyrrolidine forms. Whether these aminated metabolites are involved in the reported psychoactive and hallucinogenic effects of botanical sources of these allylbenzenes like nutmeg is not known.
Sources: en.wikipedia.org
Obesity is distributed unevenly across racial groups in the United States. Many racial minority populations disproportionately reside in low-income neighborhoods that can lack resources such as adequate healthcare, safe recreational areas, and grocery stores offering affordable, nutritious food options such as fresh fruits and vegetables. Furthermore, minority households can be more prone to obesity because of cultural food preferences and family norms. The higher prevalence of obesity among Black women compared to other demographics has been attributed to influence from cultural beauty ideals that tolerate or favor fuller body shapes. Hispanics have a high genetic susceptibility to obesity, as their Native American ancestors had adapted to a low-calorie diet, which predisposes Hispanics to obesity in the modern world, where high calorie foods are abundant.
== External links == A comprehensive NIH factsheet on iron and nutrition Iron Disorders Institute: A nonprofit group concerned with iron disorders; site has helpful links and information on iron-related medical disorders. An interactive medical learning portal on iron metabolism Information about iron outside the body
== Consequences == There are 3 levels of consequences: physiologic, intermediate, and clinical. The physiologic consequences include hypoxia, sleep fragmentation, autonomic nervous system dysregulation, or hyperoxia. The intermediate results regroup inflammation, pulmonary vasoconstriction, general metabolic dysfunction, oxidation of proteins and lipids, or increased adiposity. The clinical repercussions include pulmonary hypertension, accidents, obesity, diabetes, different heart diseases, and hypertension.
=== Recreational use === Similarly to ephedrine, methylephedrine may have misuse potential. The drug shows reinforcing effects in monkeys. It is one of the four constituents of BRON, a Japanese over-the-counter cough medicine with reports of misuse. However, addiction liability of BRON was attributed primarily to the codeine component. A case report of addiction to methylephedrine exists.
Sources: en.wikipedia.org
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.
It was developed in Russia, at the Institute of Molecular Genetics of the Russian Academy of Sciences, during the 1990s. Most published research originates from Russian institutions. Independent international replication remains limited.
Tuftsin is a natural tetrapeptide with the sequence Thr-Lys-Pro-Arg that participates in immune signaling. Selank extends that sequence with Pro-Gly-Pro at the C-terminus. The added residues are linked to greater resistance to enzymatic breakdown.
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.