Certificate of analysis 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 2026-08-01. 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.
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 |
|---|---|---|
| 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 |
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.
Enzymatic stability motivates the extra three residues at the carboxyl end. Native tuftsin is cleaved quickly by circulating aminopeptidases and carboxypeptidases, which limits its duration of action and its usefulness as a tool compound. Extending the chain with proline-rich segments is a common design tactic because proline constrains the backbone and slows proteolysis. The same Pro-Gly-Pro motif appears in other Russian-developed peptides of the era. Whether the full seven-residue chain is required for activity, or whether it acts mainly as a prodrug releasing tuftsin, remains unresolved.
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.
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.
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.
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.
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.
The 2013 annual aggregate manufacturing quota is 250 kilos. International treaties and the controlled-substances laws of most countries, such as the German Betäubungsmittelgesetz, regulate dihydrocodeine at the same level as codeine. Dihydrocodeine-based pharmaceuticals are especially used where chronic pain patients are able to have essentially OTC access to them provided they are registered with the provincial or national government as such a patient. Controlled-release dihydrocodeine is a non-prescription item in some places, especially the 60 mg strength. A report by the Ivo Šandor Organisation in 2004 listed Andorra, Spain, Gibraltar and Austria as having varying degrees of access to these and other dihydrocodeine, nicocodeine and codeine products.
== Research == Mycophenolate mofetil is beginning to be used in the management of auto-immune disorders such as idiopathic thrombocytopenic purpura (ITP), systemic lupus erythematosus (SLE), scleroderma (systemic sclerosis or SSc), and pemphigus vulgaris (PV) with success for some patients. It is also being used as a long-term therapy for maintaining remission of granulomatosis with polyangiitis, though thus far, studies have found it inferior to azathioprine. A combination of mycophenolate and ribavirin has been found to stop infection by and replication of dengue virus in vitro. It has also shown promising antiviral activity against MERS, especially in combination with interferon. Preliminary data suggest that mycophenolate mofetil might have benefits in people with multiple sclerosis. However the evidence is insufficient to determine the effects as an add‐on therapy for interferon beta-1a in people with RRMS.
===== Europe ===== In 1997, European Union health ministers voted to ban avoparcin and four additional antibiotics used to promote animal growth in 1999. In 2006, a ban on the use of antibiotics in European feed, with the exception of two antibiotics in poultry feeds, became effective. In Scandinavia, there is evidence that the ban has led to a lower prevalence of antibiotic resistance in (nonhazardous) animal bacterial populations. As of 2004, several European countries established a decline of antimicrobial resistance in humans through limiting the use of antimicrobials in agriculture and food industries without jeopardizing animal health or economic cost.
=== 1990s === The 1990s laid the groundwork for genomics and regenerative medicine. In 1990, the international Human Genome Project was officially launched with the goal of mapping and sequencing the entire human genome. The same year marked the first approved human gene therapy clinical trial, conducted by W. French Anderson to treat severe combined immunodeficiency (SCID). In 1996, researchers led by Ian Wilmut successfully cloned the first mammal from an adult somatic cell, Dolly the sheep. Shortly thereafter, in 1998, James Thomson isolated human embryonic stem cells, opening new avenues for regenerative medicine and tissue engineering.
=== Other research === Recently there has been some research to identify potential antimicrobial peptides from prokaryotes, aquatic organisms such as fish, and shellfish, and monotremes such as echidnas.
Sources: en.wikipedia.org
==== Australia ==== The non-medical use of oxycodone existed since the early 1970s, but by 2015, 91% of a national sample of injecting drug users in Australia had reported using oxycodone, and 27% had injected it in the last six months.
Reform UK removes Ian Cooper, leader of Staffordshire County Council, from the party following an investigation into online racist comments. 6 December – It is announced that transgender women will not be allowed to take part in the main event of the 2026 Labour Women's Conference. Former Conservative minister and peer Malcolm Offord defects to Reform UK, and says he will stand down from the House of Lords to campaign in the 2026 Scottish Parliament election. 7 December – Prime Minister Keir Starmer says that Angela Rayner will return to the cabinet, describing her as "hugely talented". 8 December – Essex Police are investigating allegations made by a former Reform UK councillor that the party overspent while campaigning in the Clacton constituency during the 2024 general election. Reform UK selects Addy Mo Asaduzzaman, a Bangladeshi with indefinite leave to remain in the UK, to stand in Central Southsea at local elections in May 2026. The announcement leads to criticism of the party. 9 December – Home Secretary Shabana Mahmood announces that former Children's Commissioner Baroness Anne Longfield will lead the inquiry into grooming gangs. Thirteen Labour MPs back a Liberal Democrat bill requiring the government to begin negotiations on joining a bespoke customs union with the EU, leading to a tied vote of 100–100. In her capacity as holder of the deciding vote Deputy Speaker Caroline Noakes gives her backing to the bill, allowing for it to have further debate. Ian Cooper resigns as leader of Staffordshire County Council after he was expelled by Reform UK.
=== Sleep apnea === Sleep apnea is a condition characterized by repeated interruptions in breathing during sleep, significantly affecting the flow of blood through the brain's blood vessels. These interruptions cause intermittent hypoxia, leading to vascular changes such as the constriction of cerebral blood vessels, thereby impacting overall brain blood flow. Sleep apnea can also result in reduced blood flow in the ciliary artery area, contributing to the development of NAION through various mechanisms. The results of a retrospective study investigating high altitude (7,000-9,000 feet) as a potential risk factor for NAION suggested that high-altitude-associated NAION might be linked to undiagnosed obstructive sleep apnea. The study concluded that NAION could occur under high-altitude conditions, often in younger individuals with obstructive sleep apnea and "disc-at-risk". Each apnea episode typically causes temporary increases in blood pressure and heart rate, leading to fluctuations that can result in irregular blood flow to the brain. This may cause long-term changes in the structure and function of cerebral blood vessels. The brain's mechanism for maintaining constant blood flow despite changes in systemic blood pressure, known as cerebral autoregulation, can be impaired by sleep apnea. This impairment results in periods of both reduced and excessive cerebral blood flow. Repeated airway obstruction during sleep leads to intermittent hypoxia, causing oxidative stress and damaging endothelial cells of blood vessels, including those supplying the optic nerve head.
The white flour produced after milling of wheat has only 67% of its original riboflavin amount left, so white flour is enriched in some countries. Riboflavin is also added to ready-to-eat breakfast cereals. It is difficult to incorporate riboflavin into liquid products because it has poor solubility in water, hence the requirement for riboflavin-5'-phosphate (FMN, also called E101 when used as colorant), a more soluble form of riboflavin. The enrichment of bread and ready-to-eat breakfast cereals contributes significantly to the dietary supply of the vitamin. Free riboflavin is naturally present in animal-sourced foods along with protein-bound FMN and FAD. Cows' milk contains mainly free riboflavin, but both FMN and FAD are present at low concentrations.
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.
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.