Selank 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.
Updated 2025-09-29. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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.
Proposed mechanisms centre on modulation of the GABAergic system, with reports of altered expression of genes related to GABA-A receptor subunits and changed monoamine turnover. Some studies describe inhibition of enkephalinase, the enzyme that degrades endogenous enkephalins, which may prolong opioid peptide signalling. Effects on brain-derived neurotrophic factor and on cytokine expression have also been reported. These findings come largely from animal models and small human studies, and the precise primary target remains unresolved.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Tuftsin analogue with a C-terminal Pro-Gly-Pro tail |
| Amino acid sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Abbreviated TKPRPGP in most catalogues |
| Molecular mass | About 752 Da | Value for the free peptide |
| Solubility | Freely soluble in water | Aqueous solutions are kept cold and used promptly |
| Typical storage | -20 °C, dry, protected from light | Applies to the lyophilised powder before reconstitution |
Characterization of Selank in a laboratory setting relies on standard peptide methods. Reverse-phase high-performance liquid chromatography separates the target from related impurities and provides a purity figure, commonly reported as 95 percent or higher. Mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, confirms the molecular mass and helps detect truncation or modification. Amino acid analysis can verify composition when a sequence-level check is needed. These techniques together establish identity and purity for a given lot.
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.
Animal studies have examined behaviour in tests of anxiety, memory retention and stress response, and several report changes in neurotrophic or neurotransmitter-related markers. The human evidence base is much smaller, consisting mainly of short trials conducted in Russia with limited reporting in English-language journals. Sample sizes are modest and outcome measures vary between studies, so the findings are best described as preliminary. Independent replication under modern trial standards has not been widely reported.
Outside its country of origin the compound is generally handled as a research chemical rather than an approved medicine. No regulatory approval from the United States Food and Drug Administration or the European Medicines Agency has been granted for human use. Identity and purity are normally checked by reverse-phase high-performance liquid chromatography, with mass spectrometry used to confirm the molecular mass. Lyophilised material is stored cold and desiccated, and repeated freeze-thaw cycles are avoided.
==== Luspatercept ==== Luspatercept is a drug used to treat anemia in adults with β-thalassemia, it can improve the maturation of red blood cells and reduce the need for frequent blood transfusions. It is administered by injection every three weeks. Luspatercept was authorised for use in the US in 2019 and by the European Medicines Agency in 2020.
== History == This method was developed by Solomon Berson and Rosalyn Sussman Yalow at the Veterans Administration Hospital in the Bronx, New York. This revolutionary development earned Dr. Yalow the Nobel Prize for Medicine in 1977, the second woman ever to win it. In her acceptance speech, Dr. Yalow said, "The world cannot afford the loss of the talents of half its people if we are to solve the many problems which beset us." Yalow shared the Nobel Prize with Roger Guillemin, and Andrew Schally who earned the prize based on their research into "the peptide hormone production of the brain".
FC Lokomotive Leipzig was promoted to Regionalliga Nordost after finishing Oberliga sixth due to the reserve teams of FC Rot-Weiß Erfurt, Dynamo Dresden, and FC Carl Zeiss Jena being ineligible for promotion. Lokomotive finished in tenth place in the 2012–13 season but were relegated to Oberliga Nordost after finishing 15th in 2013–14. The club stayed in contention for promotion back up to the Regionalliga during the 2014–15 season, having hired former German international Mario Basler as director of sports in early 2015. In the final match of the season, Lok supporters stormed the field after their club had fallen behind 2–0, forcing the match to be abandoned and the club to finish outside of the promotion ranks. The club finished in first place in the southern group of the NOFV-Oberliga and returned to the Regionalliga Nordost for the 2016–17 season.
Sources: en.wikipedia.org
A large number of progestins, or synthetic progestogens, have been derived from progesterone. They can be categorized into several structural groups, including derivatives of retroprogesterone, 17α-hydroxyprogesterone, 17α-methylprogesterone, and 19-norprogesterone, with a respective example from each group including dydrogesterone, medroxyprogesterone acetate, medrogestone, and promegestone. The progesterone ethers quingestrone (progesterone 3-cyclopentyl enol ether) and progesterone 3-acetyl enol ether are among the only examples that do not belong to any of these groups. Another major group of progestins, the 19-nortestosterone derivatives, exemplified by norethisterone (norethindrone) and levonorgestrel, are not derived from progesterone but rather from testosterone. A variety of synthetic inhibitory neurosteroids have been derived from progesterone and its neurosteroid metabolites, allopregnanolone and pregnanolone. Examples include alfadolone, alfaxolone, ganaxolone, hydroxydione, minaxolone, and renanolone. In addition, C3 and C20 conjugates of progesterone, such as progesterone carboxymethyloxime (progesterone 3-(O-carboxymethyl)oxime; P4-3-CMO), P1-185 (progesterone 3-O-(L-valine)-E-oxime), EIDD-1723 (progesterone 20E-[O-[(phosphonooxy)methyl]oxime] sodium salt), EIDD-036 (progesterone 20-oxime; P4-20-O), and VOLT-02 (chemical structure unreleased), have been developed as water-soluble prodrugs of progesterone and its neurosteroid metabolites.
=== Heavy metal emissions in the air === In some circumstances, mainly depending on the origin and the composition of the raw materials used, the high-temperature calcination process of limestone and clay minerals can release in the atmosphere gases and dust rich in volatile heavy metals, e.g. thallium, cadmium and mercury are the most toxic. Heavy metals (Tl, Cd, Hg, ...) and also selenium are often found as trace elements in common metal sulfides (pyrite (FeS2), zinc blende (ZnS), galena (PbS), ...) present as secondary minerals in most of the raw materials. Environmental regulations exist in many countries to limit these emissions. As of 2011 in the United States, cement kilns are "legally allowed to pump more toxins into the air than are hazardous-waste incinerators."
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Sources: en.wikipedia.org
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.
Tuftsin is a natural tetrapeptide derived from the Fc portion of immunoglobulin G. Selank retains that tetrapeptide at its N-terminus and adds three residues to improve resistance to enzymatic breakdown. The relationship is structural, and the two molecules are not interchangeable in experimental work.
It holds a product registration in Russia for intranasal use as an anxiolytic. Registrations of that kind are not automatically accepted by regulators elsewhere. In most other countries it is treated as an unapproved substance or a research material.
It is a seven-amino-acid peptide, Thr-Lys-Pro-Arg-Pro-Gly-Pro, produced by chemical synthesis rather than extracted from biological tissue. Its design is based on tuftsin, a natural immunomodulatory tetrapeptide. The C-terminal Pro-Gly-Pro segment is a common stabilising motif in short regulatory peptides.