Everything below concerns Heptapeptide. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-02-13. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Modeled on tuftsin |
| Amino acid sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Seven residues |
| Approximate molecular mass | Around 750 Da | Depends on counter-ion and hydration |
| Common forms | Lyophilized powder | Also described as aqueous solution |
| Primary origin of research | Russian laboratories | Mid-1990s onward |
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.
Reverse-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres is the standard purity method. Mass spectrometry, typically electrospray ionisation, confirms identity through the expected mass-to-charge pattern. Amino acid analysis can verify composition independently. Chiral purity requires separate techniques such as derivatisation followed by chromatographic separation, and such data are rarely reported for research-grade material.
Quantification in biological matrices relies on liquid chromatography coupled to tandem mass spectrometry with stable-isotope internal standards. Low plasma concentrations and adsorption to container surfaces both complicate measurement. Solid-phase extraction is often needed to reduce matrix interference before injection. Reported limits of quantification differ widely between laboratories, which makes direct comparison of pharmacokinetic results difficult and limits meta-analysis.
Peptide bonds are vulnerable to protease attack, and Selank is no exception. Measured half-life in serum is short, on the order of minutes in several reports, which explains why intranasal administration is the common route described in the literature. Absorption across the nasal mucosa partially bypasses first-pass hepatic metabolism. Quantitative data on human bioavailability remain limited and are difficult to compare across studies.
Biochemically, individuals with ALD show very high levels of unbranched, saturated, very long chain fatty acids, particularly cerotic acid (26:0). The level of cerotic acid in plasma does not correlate with clinical presentation. Treatment options for ALD are limited. For the childhood cerebral form, stem cell transplant and gene therapy are options if the disease is detected early in the clinical course. Adrenal insufficiency in ALD patients can be successfully treated. ALD is the most common peroxisomal inborn error of metabolism, with a minimum estimated incidence of 1:42,000 for hemizygotes and 1:16,800 for hemizygotes and heterozygotes, though the incidence is likely to increase with improved newborn screening. It does not have a significantly higher incidence in any specific ethnic group.
=== Powder feeding in continuous manufacturing === In continuous manufacturing, input raw materials and energy are fed into the system at a constant rate, and at the same time, a constant extraction of output products is achieved. The process's performance is heavily dependent on the stability of the material flowrate. For powder-based continuous processes, it is critical to feed powders consistently and accurately into subsequent unit operations of the process line, as feeding is typically the first unit operation. Feeders have been designed to achieve performance reliability, feed rate accuracy, and minimal disturbances. Accurate and consistent delivery of materials by well-designed feeders ensures overall process stability. Loss-in-weight (LIW) feeders are selected for pharmaceutical manufacturing. Loss-in-weight (LIW) feeders control material dispensing by weight at a precise rate and are often selected to minimize the flowrate variability that is caused by change of fill level and material bulk density. Importantly, feeding performance is strongly dependent on powder flow properties.
== Labeling of cells == How the labeling of RNA molecules is achieved depends on the model organism. For E.coli (bacteria) the minimum medium M9 can be used and supplemented with the stable isotope labeled variants of the needed salts. This enables labeling with 13C-carbon, 15N-nitrogen, 34S-sulfur and 2H-hydrogen. In S.cerevisiae (yeast) there are currently two possibilities: First, the use of commercially available complete growth medium, which enables labeling with 13C-carbon and/or 15N-nitrogen and second the use of minimal YNB medium which has to be supplemented with several amino acids and glucose which can be added as stable isotope labeled variants in order to achieve 13C-carbon, 15N-nitrogen and 2H-hydrogen labeling of RNA. While labeling in model organisms like E.coli and S.cerevisiae is fairly simple, stable isotope labeling in cell culture is much more challenging as the composition of the growth media is much more complex. Neither the supplementation of stable isotope labeled glucose nor the supplementation of stable isotope labeled variants of simple precursors of nucleoside biosynthesis such as glutamine and/or aspartate is sufficient for a defined mass increase higher than 2 Da. Instead, most cells kept in cell culture can be fed with stable isotope labeled methionine for labeling of methyl groups and with stable isotope labeled variants of adenin and uridine for labeling of the nucleoside's base body.
=== Influences === The band is influenced to a great extent by English metal music; in 2018, Jerry Cantrell proclaimed Black Sabbath guitarist Tony Iommi as "one of his biggest" inspirations, while Layne Staley named his "first influences" as Black Sabbath and Deep Purple. The group's work with recording engineer Dave Jerden came about because upon meeting the band, recalling: "'Metallica took Tony Iommi and sped him up. What you've done is you've slowed him down again.' And [Cantrell] looked at me and said, 'You got it.' That's how I got the gig. I totally understood what they were doing." Cantrell adjudged English rock singer Elton John as "the artist that made me want to be a musician." In addition, members of Alice in Chains have cited artists including AC/DC, Accept, Aerosmith, the Beatles, Black Flag, David Bowie, John Coltrane, Miles Davis, Dio, Funkadelic, Hanoi Rocks, Heart, Jimi Hendrix, Iron Maiden, Jethro Tull, King's X, Kiss, Led Zeppelin, Lynyrd Skynyrd, Metallica, Steve Miller, Eddie Money, Motörhead, Mudhoney, Ted Nugent, Pink Floyd, the Pixies, Queen, Queensrÿche, the Rolling Stones, Rush, Scorpions, Soundgarden, the Stooges, Television, Thin Lizzy, Robin Trower, U2, UFO, Van Halen, the Velvet Underground, Hank Williams, and ZZ Top as influential or inspirational.
On June 28, 2007, the FARC suddenly reported the death of 11 of the 12 kidnapped provincial deputies from Valle del Cauca Department. The Colombian government accused the FARC of executing the hostages and stated that government forces had not made any rescue attempts. FARC claimed that the deaths occurred during a crossfire, after an attack on one of its camps by an "unidentified military group". FARC did not report any other casualties on either side. In 2007, Venezuelan President Hugo Chávez and Colombian Senator Piedad Córdoba were acting as authorised mediators in the ongoing humanitarian exchange between the FARC and the government of Colombia. Colombian President Álvaro Uribe had given Chávez permission to mediate under the conditions that all meetings with the FARC would take place in Venezuela and that Chávez would not contact members of the Colombian military directly but instead would go through proper diplomatic channels. However, President Uribe abruptly terminated Chávez's mediation efforts on November 22, 2007, after Chávez personally contacted General Mario Montoya Uribe, the Commander of the Colombian National Army. In response, Chávez said that he was still willing to mediate, but had withdrawn Venezuela's ambassador to Colombia and placed Colombian-Venezuelan relations "in a freezer". President Uribe responded by accusing Chávez of legitimizing terrorism and pursuing an expansionist project on the continent.
Sources: en.wikipedia.org
Founded in 1896 by Fritz Hoffmann-La Roche, the company was known early on for producing various vitamin preparations and derivatives. In 1934, it became the first company to mass-produce synthetic vitamin C, under the brand name Redoxon. During the Second World War, Roche collaborated with the Nazi regime in Germany and used forced labour in its German and Polish-based factories. It also moved all its Jewish employees to the United States to save them from Nazi attention. In 1957, Hoffmann-La Roche introduced the class of tranquilizers known as benzodiazepines (with Valium and Rohypnol being the best known members). It manufactures and sells several cancer drugs and is a leader in this field. In 1956, the first antidepressant, iproniazid, was accidentally created during an experiment while synthesizing isoniazid. Originally, it had been intended to create a more efficient drug at combatting tuberculosis. Iproniazid, however, was revealed to have its own benefits; some people felt it made them feel happier. It was withdrawn from the market in the early 1960s due to toxic side-effects. In 1976, an accident at a chemical factory in Seveso, Italy, owned by a subsidiary of Roche, caused a large dioxin contamination. In 1982, the United States arm of the company acquired Biomedical Reference Laboratories for US$163.5 million. That company dated from the late 1960s, and was located in Burlington, North Carolina. That year Hoffmann-La Roche then merged it with all of its laboratories, and incorporated the merged company as Roche Biomedical Laboratories, Inc. in Burlington.
=== Other common diseases === EpiVacCorona, a peptide-based vaccine against COVID-19. IC41 is a peptide vaccine candidate against the Hepatitis C virus. It consists of five synthetic peptides along with the synthetic adjuvant called poly-l-arginine. Multimeric-001 is the most efficient peptide vaccine candidate against influenza. It contains B- and T-cell epitopes from Hemagglutinin. Matrix I and nucleoprotein are combined into a single recombinantly-expressed polypeptide. Alzheimer peptide vaccines: CAD106, UB311, Lu, AF20513, ABvac40, ACI-35, AADvac-1.
=== Glycoprotein Ib-IX-V complex (GPIb-IX-V) === This transmembrane glycoprotein complex is composed of four subunits: GPIbα, GPIbβ, GPV and GPIX. Each of them has a variable number of leucine-rich repeats. GPIbα and GPIbβ are linked by disulfide bridges, while the GPV and GPIX associate non-covalently with the complex. The GPIbα subunit bears the binding site for von Willebrand factor (vWF), α-thrombin, leukocyte integrin αMβ2 and P-selectin. The binding between GPIbα and vWF mediates the capture of platelets to the injured vascular wall. The deficiency in glycoprotein Ib-IX-V complex synthesis leads to Bernard–Soulier syndrome.
The nephrotic syndrome is characterised by the finding of edema in a person with increased protein in the urine and decreased protein in the blood, with increased fat in the blood. Inflammation that affects the cells surrounding the glomerulus, podocytes, increases the permeability to proteins, resulting in an increase in excreted proteins. When the amount of proteins excreted in the urine exceeds the liver's ability to compensate, fewer proteins are detected in the blood – in particular albumin, which makes up the majority of circulating proteins. With decreased proteins in the blood, there is a decrease in the oncotic pressure of the blood. This results in edema, as the oncotic pressure in tissue remains the same. Although decreased intravascular oncotic (i.e. osmotic) pressure partially explains the patient's edema, more recent studies have shown that extensive sodium retention in the distal nephron (collecting duct) is the predominant cause of water retention and edema in the nephrotic syndrome. This is worsened by the secretion of the hormone aldosterone by the adrenal gland, which is secreted in response to the decrease in circulating blood and causes sodium and water retention. Hyperlipidemia is thought to be a result of the increased activity of the liver.
Before the introduction of the basic chromium species in tanning, several steps are required to produce a tannable hide. The pH must be very acidic when the chromium is introduced to ensure that the chromium complexes are small enough to fit between the fibers and residues of the collagen. Once the desired level of penetration of chrome into the substance is achieved, the pH of the material is raised again to facilitate the process. This step is known as basification. In the raw state, chrome-tanned skins are greyish-blue, so are referred to as wet blue. Chrome tanning is faster than vegetable tanning (taking less than a day for this part of the process) and produces a stretchable leather which is excellent for use in handbags and garments. After application of the chromium agent, the bath is treated with sodium bicarbonate in the basification process to increase the pH to 3.8–4.0, inducing cross-linking between the chromium and the collagen. The pH increase is normally accompanied by a gradual temperature increase up to 40 °C. Chromium's ability to form such stable bridged bonds explains why it is considered one of the most effective tanning compounds. Chromium-tanned leather can contain between 4 and 5% of chromium. This efficiency is characterized by its increased hydrothermal stability of the skin, and its resistance to shrinkage in heated water.
Sources: en.wikipedia.org
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.
It originates from research in Russia, associated with the Institute of Molecular Genetics of the Russian Academy of Sciences. The first descriptions date to the mid-1990s. Most published studies come from Russian laboratories.
No, Selank itself does not occur naturally. Its backbone is based on tuftsin, which is produced in the body, but the seven-residue version is a synthetic construct. It is supplied as a manufactured peptide.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, designed as a metabolically stabilized analogue of the endogenous tetrapeptide tuftsin. It has been studied mainly against anxiety-related and cognitive endpoints rather than as an approved medicine in most jurisdictions.