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 2025-09-30. Numbers and descriptions here follow the published literature rather than marketing material.
Lyophilized selank is normally supplied as a dry powder and is considered stable for extended periods when kept cold and dry. Moisture uptake is the main practical threat, because absorbed water promotes both hydrolysis and aggregation in the solid state. Vials are usually warmed to room temperature before opening so that condensation does not form on the powder. Supplier documentation commonly specifies -20 °C for routine storage, with -80 °C used for material intended to be archived for years.
Once dissolved, the peptide is markedly less stable than the dry powder. Aqueous solutions are subject to backbone hydrolysis and to microbial growth when they are handled without sterile technique. Buffered solutions near neutral pH are common for short-term laboratory work, while acidic conditions are sometimes used to improve solubility. Analytical laboratories generally prepare working solutions fresh rather than storing them, and a residual water film left in a reopened vial can seed degradation even when the container appears dry.
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.
Selank is a synthetic heptapeptide developed in Russia. Its sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, a seven-residue chain built around the natural tetrapeptide tuftsin. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences first described the compound in the mid-1990s. The design combined the tuftsin core with an added Pro-Gly-Pro tail, a modification intended to extend the molecule's stability in biological fluids. Published work on the peptide has appeared mainly in Russian-language journals.
| Property | Value | Notes |
|---|---|---|
| Typical purity specification | 95 percent or higher by RP-HPLC | Area percentage of the main peak |
| Identity confirmation | Electrospray ionization mass spectrometry | Observed mass compared with the theoretical value near 751.9 Da |
| Recommended dry storage | -20 °C, desiccated | -80 °C for multi-year archival material |
| Solution handling | Prepare fresh; avoid long storage | Sterile filtration reduces microbial load |
| Common synonyms | TKPRPGP; TP-7 | Sequence code and laboratory designation used interchangeably |
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.
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 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.
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, 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.
Pharmacokinetic data are sparse and largely derived from animal work. After intranasal administration the peptide appears in plasma within minutes, and reported half-lives are short, on the order of minutes to tens of minutes. Degradation proceeds through ordinary proteolytic cleavage into constituent amino acids and smaller fragments. Direct evidence that intact Selank reaches brain tissue in meaningful amounts is limited, and the extent of blood-brain barrier penetration is debated. Some authors argue that fragments, not the parent peptide, carry much of the observed activity.
Published clinical work is concentrated in Russian-language journals and generally involves small samples without independent replication. Systematic reviews in English note the shortage of randomised, placebo-controlled trials and the difficulty of verifying methods from translated reports. Outcome measures vary between studies, which complicates pooling of results. Interest in the compound as a cognitive or anxiolytic agent therefore rests on a thinner evidence base than the volume of citations suggests. Replication in well-powered trials with preregistered endpoints would be needed before firm conclusions about efficacy can be drawn.
=== Support === The PDL is a part of the periodontium that provides for the attachment of the teeth to the surrounding alveolar bone by way of the cementum. PDL fibres also provide a role in load transfer between the teeth and alveolar bone. (PDL fibers absorb and transmit forces between teeth and alveolar bone. It acts as an effective support during the masticatory function.)
== Further reading == Hill, A. V.; Long, C. N. H.; Lupton, H. (1924). "Muscular Exercise, Lactic Acid, and the Supply and Utilisation of Oxygen". Proceedings of the Royal Society B: Biological Sciences. 96 (679): 438–75. doi:10.1098/rspb.1924.0037. JSTOR 81203. Laforgia, J.; Withers, R. T.; Gore, C. J. (2006). "Effects of exercise intensity and duration on the excess post-exercise oxygen consumption". Journal of Sports Sciences. 24 (12): 1247–64. doi:10.1080/02640410600552064. PMID 17101527. S2CID 25579756. Lee, C. G. (2003). "Excess post-exercise oxygen consumption in adult sockeye (Oncorhynchus nerka) and coho (O. Kisutch) salmon following critical speed swimming". Journal of Experimental Biology. 206 (18): 3253–60. doi:10.1242/jeb.00548. PMID 12909706. Thornton, M. K.; Potteiger, J. A. (2002). "Effects of resistance exercise bouts of different intensities but equal work on EPOC". Medicine & Science in Sports & Exercise. 34 (4): 715–22. doi:10.1249/00005768-200204000-00024. PMID 11932584. Gore, C. J.; Withers, R. T. (1990). "The effect of exercise intensity and duration on the oxygen deficit and excess post-exercise oxygen consumption". European Journal of Applied Physiology and Occupational Physiology. 60 (3): 169–74. doi:10.1007/BF00839153. PMID 2347316. S2CID 11724610. Lee, C. G.; Devlin, R. H.; Farrell, A. P. (2003). "Swimming performance, oxygen consumption and excess post-exercise oxygen consumption in adult transgenic and ocean-ranched coho salmon". Journal of Fish Biology. 62 (4): 753–66. doi:10.1046/j.1095-8649.2003.00057.x.
Mitchell (then of the Memphis Horns) and Earl Randle had both worked with Green a good bit. Simmons added some music and lyrics, co-writing the finished version with Mitchell and Randle; the song was later recorded by the Pointer Sisters and by Lyn Paul, the ex-New Seekers vocalist. The album also featured the song "You Belong to Me" (co-written by McDonald and Carly Simon, who had a hit with her own version of the tune). To help promote Livin' on the Fault Line, the band performed live on the PBS show Soundstage. Baxter used an early type of guitar synthesizer (made by Roland) on many of the tracks (especially the title track and "Chinatown").
A PSMA scan is a nuclear medicine imaging technique used in the diagnosis and staging of prostate cancer. It is carried out by injection of a radiopharmaceutical with a positron or gamma emitting radionuclide and a prostate-specific membrane antigen (PSMA) targeting ligand. After injection, imaging of positron emitters such as gallium-68 (68Ga), copper-64 (64Cu), and fluorine-18 (18F) is carried out with a positron emission tomography (PET) scanner. For gamma emitters such as technetium-99m (99mTc) and indium-111 (111In) single-photon emission computed tomography (SPECT) imaging is performed with a gamma camera. As well as the diagnosis and staging of prostate cancer, PSMA imaging can also be used to assess suitability for and plan treatment with external beam radiotherapy and PSMA-targeted radionuclide therapy.
Sources: en.wikipedia.org
Similar behavior is exhibited by some iron compounds, such as the ferrites including the mineral magnetite, a crystalline form of the mixed iron(II,III) oxide Fe3O4 (although the atomic-scale mechanism, ferrimagnetism, is somewhat different). Pieces of magnetite with natural permanent magnetization (lodestones) provided the earliest compasses for navigation. Particles of magnetite were extensively used in magnetic recording media such as core memories, magnetic tapes, floppies, and disks, until they were replaced by cobalt-based materials.
Tendinitis is a type of overuse injury to the tendons, which demonstrates signs of inflammation of tendons around a joint. Tendinitis is the most common cause of shoulder pain and also leg pain . Tendinitis occurs when there is repetitive stress on the subacromial bursa, which causes the bones to make contact with the tendons and irritate them.
Endoneurium. Each nerve axon, or fiber is surrounded by the endoneurium, which is also called the endoneurial tube, channel or sheath. This is a thin, delicate, protective layer of connective tissue. Perineurium. Each nerve fascicle containing one or more axons, is enclosed by the perineurium, a connective tissue having a lamellar arrangement in seven or eight concentric layers. This plays a very important role in the protection and support of the nerve fibers and also serves to prevent the passage of large molecules from the epineurium into a fascicle. Epineurium. The epineurium is the outermost layer of dense connective tissue enclosing the (peripheral) nerve.
Sources: en.wikipedia.org
== Biosynthesis == In the morphine biosynthetic pathway, salutaridinol is derived in three steps from (R)-reticuline. First, (R)-reticuline undergoes an oxidation at each of its phenol rings mediated by the cytochrome P-450-dependent monooxygenase salutaridine synthase. These phenol group oxidations yield a diradical species that undergoes ortho coupling to the phenol group of the tetrahydroisoquinoline and para coupling to the benzyl group to create the salutaridinol precursor salutaridine. A stereospecific reduction of the salutaridine carbonyl group by salutaridine: NADPH 7-oxidoreductase then generates salutaridinol.
The community centre includes a swimming pool (the only public one in the islands), a sports centre, and a school. A grass football pitch is located by the community centre. A separate building houses the college of further education and the library. A new sports centre is under construction to the south of the town centre, next to a newly-laid floodlit all-weather pitch. Stanley Racecourse, located on the west side of Stanley, holds a two-day horse racing meeting every year on 26 and 27 December. The Christmas races have been held here for over 100 years. Stanley Golf Course has an 18-hole course and a club house. It is also located to the west of Stanley. King Edward VII Memorial Hospital is the islands' main hospital, with doctors' practice and surgery, radiology department, dental surgery and emergency facilities. The Port Stanley Airport operates internal flights, and scheduled international passenger flights operate from the RAF Mount Pleasant military airbase. Stanley is also home to the Falkland Islands Radio Station (FIRS), the Stanley office of the British Antarctic Survey, and the office of the weekly Penguin News newspaper.
A monolithic HPLC column, or monolithic column, is a column used in high-performance liquid chromatography (HPLC). The internal structure of the monolithic column is created in such a way that many channels form inside the column. The material inside the column which separates the channels can be porous and functionalized. In contrast, most HPLC configurations use particulate packed columns; in these configurations, tiny beads of an inert substance, typically a modified silica, are used inside the column. Monolithic columns can be broken down into two categories, silica-based and polymer-based monoliths. Silica-based monoliths are known for their efficiency in separating smaller molecules while, polymer-based are known for separating large protein molecules.
Sources: en.wikipedia.org
Sealed, desiccated storage at -20 °C or colder is the standard recommendation for research-grade material. Vials should reach room temperature before they are opened, which limits condensation. Repeated temperature cycling is discouraged.
A reported purity value reflects the share of the main peak in one chromatographic run and says nothing about identity. Confirming that the expected sequence is present requires a separate measurement such as mass spectrometry. Purity and identity are distinct questions.
A mass spectrum reports the molecular masses present in a sample and shows whether they match the value expected for selank, near 751.9 Da. It also flags common artifacts such as truncation or adduct formation. It does not establish correct stereochemistry or complete sequence order on its own.
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.