If you have been reading about tuftsin 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 2026-03-27. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Selank is a hydrophilic peptide and dissolves readily in water and in aqueous buffers. The lyophilised powder is typically a white to off-white solid. Because short peptides are prone to hydrolysis and oxidation, handling benefits from limiting exposure to heat, moisture and strong light. Working solutions are commonly prepared in sterile water or saline, and repeated freeze-thaw cycles are avoided to reduce aggregation and loss of activity. These practices reflect general laboratory convention rather than published stability specifications.
Reported activity for Selank centers on anxiolytic and nootropic effects. Russian clinical reports describe use in anxiety and in cognitive or attention-related complaints. Most of this evidence comes from studies conducted by the same research groups that developed the peptide. Independent replication in other countries remains limited, and no major Western regulatory agency has approved the compound for any indication. The gap between local reports and external verification is a recurring point in discussions of the peptide.
Tuftsin, the parent structure, is a naturally occurring immunomodulatory tetrapeptide released from the Fc region of immunoglobulin G by spleen enzymes. Selank extends this four-residue sequence with three additional amino acids. The stated rationale is that the added tail slows enzymatic breakdown and may influence receptor interactions. How the full heptapeptide behaves at the molecular level is not firmly established, and proposed mechanisms often involve indirect modulation of neurotransmitter or immune signaling rather than a single defined target.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilised solid form |
| Solubility class | Freely soluble in water | Hydrophilic heptapeptide |
| Dry storage temperature | -20 degrees Celsius or lower | Sealed, desiccated, protected from light |
| Solution storage | 2 to 8 degrees Celsius short term | Avoid repeated freeze-thaw cycles |
| Common identification method | Reversed-phase HPLC with mass spectrometry | Confirms purity and molecular mass |
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.
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.
Reported pharmacological effects center on reduced anxiety-like behavior in animal models and on measures of memory and learning. Proposed contributing mechanisms include modulation of GABAergic signaling, shifts in monoamine turnover, and changes in the activity of enzymes that degrade neuropeptides. Effects on the expression of genes linked to neuroplasticity have also been described. No single molecular target is widely accepted, and whether the behavioral findings arise from one pathway or several remains an open question.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed as a stabilized analogue of tuftsin, a naturally occurring tetrapeptide fragment derived from the immunoglobulin heavy chain. The additional Pro-Gly-Pro segment at the carboxyl terminus is intended to slow enzymatic cleavage. The compound is usually described in the literature as a synthetic peptide with anxiolytic and cognitive-related activity, a label that reflects a research context rather than an approved therapeutic category.
Most published work on selank originates from a small number of research groups in the Russian Federation. A large share of that record appears in Russian-language journals, which limits access for readers who rely on English-indexed databases. Independent replication by laboratories outside the original research network is sparse in publicly available sources. This concentration of origin and language is a frequently noted feature when the compound is summarized in broader reviews of synthetic peptides.
Published clinical evidence is limited. Most controlled trials were conducted in Russia, enrolled modest numbers of participants, and appeared in Russian-language journals, which restricts independent verification. Reported outcomes include lower anxiety scores, improved attention and memory measures, and changes in fatigue ratings. Reviews written in English note methodological limitations such as small samples and inconsistent endpoints. Whether the compound produces clinically meaningful benefit relative to established anxiolytics is therefore an open question rather than an established finding.
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.
It often happens that the amount of antibody available to the researcher for their immunoprecipitation experiment is less than sufficient to saturate the agarose beads to be used in the immunoprecipitation. In these cases the researcher can end up with agarose particles that are only partially coated with antibodies, and the portion of the binding capacity of the agarose beads that is not coated with antibody is then free to bind anything that will stick, resulting in an elevated background signal due to non-specific binding of lysate components to the beads, which can make data interpretation difficult. While some may argue that for these reasons it is prudent to match the quantity of agarose (in terms of binding capacity) to the quantity of antibody that one wishes to be bound for the immunoprecipitation, a simple way to reduce the issue of non-specific binding to agarose beads and increase specificity is to preclear the lysate, which for any immunoprecipitation is highly recommended.
=== Differential diagnosis === There are many causes of chest pain, which can originate from the heart, lungs, gastrointestinal tract, aorta, and other muscles, bones and nerves surrounding the chest. In addition to myocardial infarction, other causes include angina, insufficient blood supply (ischemia) to the heart muscles without evidence of cell death, gastroesophageal reflux disease; pulmonary embolism, tumors of the lungs, pneumonia, rib fracture, costochondritis, heart failure and other musculoskeletal injuries. Rarer severe differential diagnoses include aortic dissection, esophageal rupture, tension pneumothorax, and pericardial effusion causing cardiac tamponade. The chest pain in an MI may mimic heartburn. Causes of sudden-onset breathlessness generally involve the lungs or heart – including pulmonary edema, pneumonia, allergic reactions and asthma, and pulmonary embolus, acute respiratory distress syndrome and metabolic acidosis. There are many different causes of fatigue, and myocardial infarction is not a common cause.
The band posted a tribute to him on their website in September 2022. In 2023, Johnston, McDonald, and Simmons (as the Doobie Brothers) were nominated for induction into the Songwriters Hall of Fame. In addition, a continuation of their 50th Anniversary tour was planned for the year. The Doobies started their 2023 touring schedule in Australia and Japan in April before making their way to Hawaii and then returning to the continental U.S. in May. Three days before they were set to perform in Hollywood, Florida, the band released a statement that Tom Johnston would be undergoing surgery following severe back pain and would not be able to join the band on the upcoming leg of the 50th Anniversary Tour. Simmons, McDonald, and McFee continued the 2023 touring schedule in Johnston's absence. Lead vocals normally performed by Johnston were shared between Simmons, McDonald, and bassist John Cowan. In June 2023, Simmons said in an interview that the band will be releasing new music the next year with McDonald. The band opened for the Eagles on the latter's The Long Goodbye Tour in November 2023, replacing Steely Dan due to Donald Fagen's health issues. On November 17, 2023, the Doobie Brothers released a new single entitled "Lahaina" to benefit the families and individuals affected by the 2023 Hawaii wildfires. The song, produced by John Shanks, features Mick Fleetwood on drums, Jake Shimabukuro on ukulele, and Henry Kapono on vocals. In 2024 a fully healed Tom Johnston rejoined the Doobies, who continued on with their 50th Anniversary tour.
==== Blood donation ==== Frequent blood donors are also at risk for developing iron deficiency anemia. When whole blood is donated, approximately 200 mg of iron is lost from the body. The blood bank screens people for anemia before drawing blood for donation. If the patient has anemia, blood is not drawn. Less iron is lost if the person is donating platelets or white blood cells.
Sources: en.wikipedia.org
More recent evidence suggests that estrogen promotes cholestasis via its metabolite estradiol-17-β-D-glucuronide (E2). E2 secreted into the canaliculi by MRP2 was found to repress the transcription of bile salt export pump (BSEP), the apical ABC transporter responsible for exporting monoanionic conjugated bile acids from hepatocytes into bile canaliculi. E2 was also found to upregulate miR-148a, which represses expression of the pregnane X receptor (PXR). PXR is a nuclear receptor in hepatocytes that senses intracellular bile acid concentrations and regulates gene expression accordingly to increase bile efflux. Genetic predisposition for ICP is suggested by familial and regional clustering of cases. Several studies have implicated heterozygous mutations of the genes ABCB11 and ABCB4 in ICP, which respectively encode the canalicular transport proteins BSEP and multidrug resistance protein 3 (MDR3). MDR3 is responsible for exporting phosphatidylcholine, the major lipid component of bile, into bile canaliculi where it forms micelles with bile salts to prevent the latter from damaging luminal epithelium. Bile flow requires canalicular secretion of both bile salts and phosphatidylcholine. MDR3 mutations are an established predisposing factor, found in 16% of ICP cases. More recently, studies have demonstrated involvement of BSEP mutations in at least 5% of cases. The V444A polymorphism of ABCB11 in particular may lead to ICP by causing a reduction in hepatic BSEP expression and consequently decreased bile salt export.
However, only Lockyer proposed that the line was due to a new element, which he named after the Sun. The formal discovery of the element was made in 1895 by chemists Sir William Ramsay, Per Teodor Cleve, and Nils Abraham Langlet, who found helium emanating from the uranium ore cleveite, which is no longer regarded as a separate mineral species, but as a variety of uraninite. In 1903, large reserves of helium were found in natural gas fields in parts of the United States, by far the largest supplier of the gas. Liquid helium is used in cryogenics (its largest single use, consuming about a quarter of production), and in the cooling of superconducting magnets, with its main commercial application in MRI scanners. Helium's other industrial uses—as a pressurizing and purge gas, as a protective atmosphere for arc welding, and in processes such as growing crystals to make silicon wafers—account for half of the gas produced. A small but well-known use is as a lifting gas in balloons and airships. As with any gas whose density differs from that of air, inhaling a small volume of helium temporarily changes the timbre and quality of the human voice. In scientific research, the behavior of the two fluid phases of helium-4 (helium I and helium II) is important to researchers studying quantum mechanics (in particular the property of superfluidity) and to those looking at the phenomena, such as superconductivity, produced in matter near absolute zero. On Earth, it is relatively rare—5.2 ppm by volume in the atmosphere.
=== Nerve cell === Nerve cells comprise a small cell body and a very long segment called the axon. The cell body resides in the spinal cord and the axon extends all the way to the innervation target of the nerve. Peripheral nerve axons can be longer than 100 cm as they may need to travel along the full length of a limb to reach their innervation target, while the cell body is only 100 micrometers long. Nerves may be myelinated or unmyelinated. Myelinated nerves have the axon covered by segments of schwann cells, which are short and concentrically wrapped around the diameter of an axon to give the appearance of a sausage-like mass and called a myelin sheath. The schwann cells are arranged in pattern such all parts of the axon are wrapped in schwann cells and successive schwann cells are separated by a very small distance. This separation gap is called a node of Ranvier. Unmyelinated nerves are also surrounded by schwann cells but the schwann cells are not wrapped around the axon multiple times to form a myelin sheath.
Sources: en.wikipedia.org
=== Heart failure === DCA has been investigated as a treatment for post-ischemic recovery. There is also evidence that DCA improves metabolism by NADH production stimulation, but may lead to a depletion of NADH in normoxia.
As with animal findings, both TMPAA and NAM have been said to be inactive based on human tests. It has also been noted that metabolites like TMPA and TMPE are rapidly metabolized. As such, metabolites of mescaline like TMPA, TMPE, TMPAA, and NAM do not appear to be involved in the drug's psychedelic-related effects. 3,4,5-Trimethoxyamphetamine (TMA), the α-methyl analogue of mescaline and an MAO-resistant psychedelic, is only about twice as potent as mescaline as a psychedelic in humans despite having similar serotonin receptor affinity. This suggests that the deamination of mescaline has a relatively limited impact on its potency, compared to for example the 2C series of psychedelics. Another analogue of mescaline, the deuterated isotopologue Alpha-D (α,α-dideuteromescaline), has been reported to be roughly one-third more potent than mescaline as a psychedelic in humans, albeit based on limited testing. This is consistent with findings of about one-third of a dose of mescaline being metabolized via deamination.
In 1996, it became a contract research organization (CRO) for the biopharmaceutical sector and entered into collaboration with SmithKline Beecham biologicals (Rixensart, Belgium) for the production of recombinant proteins for phase I, II and III clinical trials. In addition to its pharmaceutical manufacturing activities, Eurogentec became a service company for the biotechnical research industry and university laboratories. In 1999, Eurogentec acquired Oswel Research Product Ltd. a biotechnology company based in Southampton, Great Britain and specialized in the synthesis of chemically modified and complex oligonucleotides and their analogues (DNA, RNA, PNA). In 2002, Eurogentec acquired Wita Proteomics, a company specialized in proteomics services, based in Berlin (Germany). A few months later, Eurogentec installed its US office in San Diego for the production of oligonucleotides (EGT NA).
Isotopomerism is analogous to constitutional isomerism or stereoisomerism of different elements in a structure. Depending on the formula and the symmetry of the structure, there might be several isotopomers of one isotopologue. For example, ethanol has the molecular formula C2H6O. Mono-deuterated ethanol, C2H5DO or C2H52HO, is an isotopologue of it. The structural formulas CH3−CH2−O−D and CH2D−CH2−O−H are two isotopomers of that isotopologue.
Sources: en.wikipedia.org
Dry powder is normally held at -20 degrees Celsius or below in a sealed, light-protected container with desiccant. Brief room-temperature handling during weighing is generally tolerated. Storage instructions vary between suppliers, so the accompanying certificate of analysis should be followed.
Reversed-phase HPLC establishes purity, while mass spectrometry confirms the expected molecular mass. Sequence confirmation may use tandem mass spectrometry or peptide mapping. A certificate of analysis typically reports these results alongside the analytical method applied.
In Russia it is a registered medicine available by prescription. In many other countries it is not approved for human use and is supplied only as a research chemical. Import and possession rules differ by jurisdiction, and buyers are responsible for checking local requirements.
Selank is a synthetic peptide made of seven amino acids. It is modeled on tuftsin, a natural tetrapeptide, with an added three-residue tail. It is not a small-molecule drug.