If you have been reading about Regulatory peptide 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 2025-12-02. 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. 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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C33H57N11O9 | Free peptide form |
| Molecular mass | About 751.9 Da | Calculated average mass |
| Amino acid sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form TKPRPGP |
| Structural basis | Tuftsin analogue | Extended version of a natural tetrapeptide |
| Development origin | Russian Academy of Sciences | Work carried out from the 1980s onward |
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.
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.
Addiction medicine deals with the treatment of addiction. Aerospace medicine deals with medical problems related to flying and space travel. Biomedical Engineering is a field dealing with the application of engineering principles to medical practice. Clinical pharmacology is concerned with how systems of therapeutics interact with patients. Conservation medicine studies the relationship between human and non-human animal health, and environmental conditions. Also known as ecological medicine, environmental medicine, or medical geology. Disaster medicine deals with medical aspects of emergency preparedness, disaster mitigation and management. Diving medicine (or hyperbaric medicine) is the prevention and treatment of diving-related problems. Evolutionary medicine is a perspective on medicine derived through applying evolutionary theory. Forensic medicine deals with medical questions in legal context, such as determination of the time and cause of death, type of weapon used to inflict trauma, reconstruction of the facial features using remains of deceased (skull) thus aiding identification. Gender-based medicine studies the biological and physiological differences between the human sexes and how that affects differences in disease. Health informatics is a relatively recent field that deal with the application of computers and information technology to medicine. Hospice and Palliative Medicine is a relatively modern branch of clinical medicine that deals with pain and symptom relief and emotional support in patients with terminal illnesses including cancer and heart failure.
Many researchers proposed that at the physiological pH, GHK-Cu complexes can form binary and ternary structures which may involve amino acid histidine and/or the copper binding region of the albumin molecule. Lau and Sarkar found also that GHK can easily obtain copper 2+ bound to other molecules such as the high affinity copper transport site on plasma albumin (albumin binding constant log 10 =16.2 vs. GHK binding constant 16 log 10 =16.44). It has been established that copper (II) redox activity is silenced when copper ions are complexed with the GHK tripeptide, which allows the delivery of non-toxic copper into the cell.
Benzodiazepines are positive allosteric modulators of the GABA type A receptors (GABAA). The GABAA receptors are ligand-gated chloride-selective ion channels that are activated by GABA, the major inhibitory neurotransmitter in the brain. The binding of benzodiazepines to this receptor complex promotes the binding of GABA, which in turn increases the total conduction of chloride ions across the neuronal cell membrane. This increased chloride ion influx hyperpolarizes the neuron's membrane potential. As a result, the difference between resting potential and threshold potential is increased, and firing is less likely. As a result, the arousal of the cortical and limbic systems in the central nervous system is reduced. The GABAA receptor is a heteromer composed of five subunits, the most common ones being two αs, two βs, and one γ (α2β2γ). For each subunit, many subtypes exist (α1–6, β1–3, and γ1–3). GABAA receptors containing the α1 subunit mediate the sedative, anterograde amnesic, and partly the anticonvulsive effects of diazepam. GABAA receptors containing α2 mediate the anxiolytic actions and, to a large degree, the myorelaxant effects. GABAA receptors containing α3 and α5 also contribute to benzodiazepines myorelaxant actions, whereas GABAA receptors comprising the α5 subunit were shown to modulate the temporal and spatial memory effects of benzodiazepines. Diazepam is not the only drug to target these GABAA receptors. Drugs such as flumazenil also bind to GABAA to induce their effects.
In two books, Grenzen der Sozialdisziplinierung Austieg und Krise der deutschen Jugendfürsorge von 1878 bis 1932 (The Limits of Social Discipline The Rise and Crisis of German Youth 1878 to 1932) and its sequel, Jugend zwischen Krieg und Krise Lebenswelten von Arbeiterjungen in der Weimarer Republik (Youth Between War and Crisis Lifeworlds of Working Class Boys in the Weimar Republic), Peukert examined how the concept of jugendlicher ("youth") changed from the 19th into the 20th centuries and how the state sought to dominate the lives of youth people via education and mandatory activities. Both books were part of Peukert' habilitation, and reflected his lifelong interest in the experiences of young people in the Imperial, Weimar and Nazi eras.
Sources: en.wikipedia.org
=== Injections and implants === In 1933 or 1934, Schering introduced progesterone in oil solution as a medication by intramuscular injection under the brand name Proluton. This was the first pharmaceutical formulation of progesterone to be marketed for medical use. It was initially a corpus luteum extract, becoming pure synthesized progesterone only subsequently. A clinical study of the formulation was published in 1933. Multiple formulations of progesterone in oil solution for intramuscular injection, under the brand names Proluton, Progestin, and Gestone, were available by 1936. A parenteral route was used because oral progesterone had very low activity and was thought to be inactive. Progesterone was initially very expensive due to the large doses required. However, with the start of steroid manufacturing from diosgenin in the 1940s, costs greatly decreased. Subcutaneous pellet implants of progesterone were first studied in women in the late 1930s. They were the first long-acting progestogen formulation. Pellets were reported to be extruded out of the skin within a few weeks at high rates, even when implanted beneath the deep fascia, and also produced frequent inflammatory reactions at the site of implantation. In addition, they were absorbed too slowly and achieved unsatisfactorily low progesterone levels. Consequently, they were soon abandoned, in favor of other preparations such as aqueous suspensions.
== Sources == Bushkovitch, Paul (5 December 2011). A Concise History of Russia. Cambridge University Press. ISBN 978-1-139-50444-7. Crummey, Robert O. (6 June 2014). The Formation of Muscovy 1300 - 1613. Routledge. ISBN 978-1-317-87200-9. Fennell, John (15 November 2023). The Emergence of Moscow, 1304–1359. Univ of California Press. ISBN 978-0-520-34759-5. Kuchkin, Vladimir A. (2013). "Московское великое княжество" [Grand Principality of Moscow]. In Kravets, S. L. (ed.). Большая российская энциклопедия. Том 21: Монголы — Наноматериалы (in Russian). Большая российская энциклопедия. pp. 308–310. ISBN 978-5-85270-355-2. Archived from the original on 20 May 2026. Riasanovsky, Nicholas V.; Steinberg, Mark D. (2019). A history of Russia (Ninth ed.). New York: Oxford University Press. ISBN 978-0-19-064558-8. Smirnova, E. S. (2013). "Московская школа" [Moscow school]. In Kravets, S. L. (ed.). Большая Российская энциклопедия. Том 21: Монголы — Наноматериалы (in Russian). Большая Российская энциклопедия. pp. 273–274. ISBN 978-5-85270-355-2.
== Treatment == As of 2018, there is no cure for GSD, and treatment is restricted to manage symptoms and associated problems. Thus, sodium bicarbonate is recommended to treat metabolic acidosis, and antioxidants, among them vitamins E and C, can reduce oxidative damage.
==== MeSH E05.760.833 – tissue preservation ==== MeSH E05.760.833.230 – blood preservation MeSH E05.760.833.445 – cold ischemia MeSH E05.760.833.660 – organ preservation MeSH E05.760.833.890 – semen preservation
==== Dihydropyrazine and pyrazine synthesis ==== Reaction of the lactam-derived enol phosphates 4 of 2,5-diketopiperazines with palladium catalyzed reactions (reduction, Suzuki and Stille cross-coupling reactions) enables the synthesis of a range of functionalised 1,4-dihydropyrazines 5 which can be aromatized to 1,4-pyrazines 6 in the presence of acid.
Sources: en.wikipedia.org
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.
The core four residues correspond to tuftsin, which occurs naturally as part of immunoglobulin G. The full seven-residue sequence, however, is not a known endogenous peptide. It is a laboratory-designed analogue intended to combine tuftsin-like activity with greater resistance to breakdown.
No single receptor has been confirmed as the primary target. Reports describe involvement of the GABAergic system, interference with enkephalin degradation, and shifts in neurotrophic factor expression. Because these observations come from different models and assays, they have not yet been integrated into one accepted mechanism.
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.