heptapeptide raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2025-11-03 and is reviewed periodically as new material appears.
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 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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Analog of the tetrapeptide tuftsin |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Reported consistently across pharmacopoeial descriptions |
| Appearance | White to off-white lyophilized powder | Typical form of research-grade material |
| Solubility | Freely soluble in water | Aqueous buffers; poor in nonpolar solvents |
| Typical storage temperature | -20 degrees Celsius | Lyophilized powder; protect from moisture |
Quality assessment of Selank samples typically combines purity determination with identity confirmation and counter-ion analysis. Purity is usually reported as a percentage by chromatographic area, with values above 95 percent often quoted for research-grade material. Water content and residual solvents are checked in lyophilized batches because they affect both stability and accurate mass determination. A reported purity figure does not by itself establish that a sample is the intended sequence, so orthogonal methods are needed to rule out sequence isomers or truncation products.
Characterization of Selank in laboratory settings relies on standard peptide analytical techniques. Reverse-phase high-performance liquid chromatography separates the peptide from related impurities and degradation products, while mass spectrometry confirms molecular identity through accurate mass measurement. Amino acid analysis and peptide sequencing verify the primary structure when reference material is unavailable. Because Selank is a short chain, fragmentation-based analysis produces a diagnostic ion pattern that supports confident identification.
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.
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.
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.
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.
Published work on this peptide almost always uses intranasal delivery, with drops or a spray applied to the nasal mucosa. Some animal experiments have used subcutaneous or intraperitoneal injection, and a smaller number have compared routes directly. Oral administration is not a focus of the literature, because short peptides of this size are broken down by digestive enzymes and cross intestinal barriers poorly. How much of an intranasal dose reaches the bloodstream intact in humans remains an open question.
Lactation suppression Hyperprolactinemia Adjunctive therapy of prolactin-producing pituitary gland tumors (prolactinomas); Monotherapy of Parkinson's disease in the early phase; Combination therapy, together with levodopa and a decarboxylase inhibitor such as carbidopa, in progressive-phase Parkinson's disease; In some countries also: ablactation and dysfunctions associated with hyperprolactinemia (amenorrhea, oligomenorrhea, anovulation, nonpuerperal mastitis and galactorrhea); Treatment of uterine fibroids. Adjunctive therapy of acromegaly: Cabergoline has low efficacy in suppressing growth hormone levels and is highly efficient in suppressing hyperprolactinemia, which is present in 20–30% of acromegaly cases. Growth hormone and prolactin are similar structurally and have similar effects in many target tissues; therefore, targeting prolactin may help symptoms when growth hormone secretion cannot be sufficiently controlled by other methods. Cabergoline is frequently used as a first-line agent in the management of prolactinomas due to its higher affinity for D2 receptor sites, less severe side effects, and more convenient dosing schedule than the older bromocriptine, though in pregnancy bromocriptine is often still chosen since there is less data on safety in pregnancy for cabergoline.
== Bibliography == Atwood, David A. (2013). Radionuclides in the Environment. John Wiley and Sons. ISBN 978-1-118-63269-7. Emsley, John (2011). Nature's Building Blocks: An A-Z Guide to the Elements. New York: Oxford University Press, USA. ISBN 978-0-199-60563-7. Hoffman, Klaus (2001). Otto Hahn: Achievement and Responsibility. Springer. Bibcode:2002ohar.book.....H. ISBN 978-0-387-95057-0. Lemire, Robert J. (2001). Chemical Thermodynamics of Neptunium and Plutonium. Amsterdam: Elsevier. ISBN 978-0-444-50379-4. Rhodes, Richard (2012). The Making of the Atomic Bomb (25th Anniversary ed.). New York: Simon & Schuster. ISBN 978-1-451-67761-4. Yoshida, Zenko; Johnson, Stephen G.; Kimura, Takaumi; Krsul, John R. (2006). "Neptunium". In Morss, Lester R.; Edelstein, Norman M.; Fuger, Jean (eds.). The Chemistry of the Actinide and Transactinide Elements (PDF). Vol. 3 (3rd ed.). Dordrecht, the Netherlands: Springer. pp. 699–812. doi:10.1007/1-4020-3598-5_6. ISBN 978-1-4020-3555-5. Archived from the original (PDF) on January 17, 2018.
== Biochemistry == A1 receptors are implicated in sleep promotion by inhibiting wake-promoting cholinergic neurons in the basal forebrain. A1 receptors are also present in smooth muscle throughout the vascular system. In humans, the adenosine A1 receptor has been found to be most highly expressed in the brain, with lower expression in other tissues such as the testis, pancreas, and heart.
=== Late 20th century === In 1988, Liautaud met Jamie Coulter, who at that time was a Pizza Hut franchisee and would later become the CEO of Lone Star Steakhouse & Saloon. Coulter mentored Liautaud and "taught [him] how to effectively run multiple units." Liautaud continued opening more stores and developed a prototype before beginning franchising in 1994. In 1994, he sold his first Jimmy John's franchise, in addition to the 10 stores owned by Liautaud himself. The first franchise store opened in Eau Claire, Wisconsin. In 2001, the hundredth Jimmy John's store opened in Mt. Pleasant, Michigan. By 2002, the company had about 200 stores, 10% of which were corporate stores that Liautaud oversaw himself. However, Liautaud noticed that sales at the stores he owned were outpacing the franchised stores by a wide margin. Liautaud stopped selling franchises for one year to give support to stores that were struggling. Together with his partner, and now president & CEO, James North, he visited 70 of the poorest-performing stores. After 18 months of getting the stores "back to basics" and instilling in them "some of that initial spark", he was able to help the stores become more profitable.
Sources: en.wikipedia.org
For services to the community in Deal, Kent. Anthony William Assheton Spiegelberg, . For political service. Olive Patricia Stadler. For services to Relate and to Family Mediation in Tyneside. Peter Edward Paul Staples, lately Pay Band 11, Her Majesty's Stationery Office. Jean Stevenson, Typist/Clerical Assistant, Grange Academy, Kilmarnock. For services to Education. Grace Teresa Stewart. For public service. John Kenneth Stewart, lately Retained Sub-Officer, Grampian Fire Brigade. For services to the Fire Service. Wilfrid Bowring Stoddart. For services to Young People in Runcorn, Cheshire. Duncan John Strathdee, Bed and Breakfast Proprietor, Perthshire. For services to Tourism. Helen Strathdee, Bed and Breakfast Proprietor, Perthshire. For services to Tourism. Leslie Sussman, Member, London Borough of Barnet. For services to Local Government. Helena Sutherland. For services to the Royal Bntsh Legion Scotland. John Sanderson Swain. For services to Grimsby Hospital, North East Lincolnshire. James Edward Keir Tabert, General Medical Practitioner, Luton, Bedfordshire. For services to Medicine. Ian Michael Wade Taggart, . For services to Sailing for Disabled People. David Harris Tanner, Team Leader, Her Majesty's Board of Customs and Excise, and Honorary Chairman of Rex Blind Parties. David Anthony Taylor, lately Area Water Quality Manager, National Rivers Authority, Anglian Region. For services to the Environment. Carole Anne Terrington. For services to the community in Sundon, Bedfordshire. Gwendoline Tew. For services to the community in Llandow, South Wales.
Larger doses do not appear to increase risks in this population. A broader retrospective study found that the rate of hyperkalemia in gender-diverse individuals is correlated with age, with those above 45 years old being more at risk. The finding suggests that patients below or at 45 years old without other conditions that affect potassium handling can be spared from routine monitoring.
Machine learning algorithms train their models to distinguish known disease-associated from neutral mutations whereas other methods do not explicitly train their models but almost all methods exploit the evolutionary conservation assuming that changes at conserved positions tend to be more deleterious. While majority of methods provide a binary classification of effects of mutations into damaging and benign, a new level of annotation is needed to offer an explanation of why and how these mutations damage proteins. Moreover, if the mutation occurs in the region of the gene where transcriptional machinery binds to the protein, the mutation can affect the binding of the transcription factors because the short nucleotide sequences recognized by the transcription factors will be altered. Mutations in this region can affect rate of efficiency of gene transcription, which in turn can alter levels of mRNA and, thus, protein levels in general. Point mutations can have several effects on the behavior and reproduction of a protein depending on where the mutation occurs in the amino acid sequence of the protein. If the mutation occurs in the region of the gene that is responsible for coding for the protein, the amino acid may be altered. This slight change in the sequence of amino acids can cause a change in the function, activation of the protein meaning how it binds with a given enzyme, where the protein will be located within the cell, or the amount of free energy stored within the protein.
=== European settlement === The first European settlement in South Africa was founded at the Cape of Good Hope in 1652, and administered as part of the Dutch Cape Colony. As a result of political turmoil in the Netherlands, the British occupied the Cape three times during the Napoleonic Wars, and the occupation became permanent after the Battle of Blaauwberg in 1806. The colony was then home to about 26,000 colonists settled under Dutch rule. Most represented old Dutch families brought to the Cape during the late 17th and early 18th centuries. Broadly speaking, the colonists included distinct subgroups, including the Boers. The Boers were itinerant farmers who lived on the colony's frontiers, seeking better pastures for their livestock. Many were dissatisfied with aspects of British administration, in particular with Britain's abolition of slavery in 1834. Boers who used forced labor were unable to collect compensation for their slaves. Between 1836 and 1852, many elected to migrate away from British rule in what became known as the Great Trek. Around 15,000 trekking Boers departed the Cape Colony and followed the eastern coast towards Natal. After Britain annexed Natal in 1843, they journeyed farther north into South Africa's eastern interior. There, they established two independent Boer republics: the South African Republic (1852; also known as the Transvaal Republic) and the Orange Free State (1854).
=== Disorder databases === Databases have been established to annotate protein sequences with intrinsic disorder information. The DisProt database contains a collection of manually curated protein segments which have been experimentally determined to be disordered. MobiDB is a database combining experimentally curated disorder annotations (e.g. from DisProt) with data derived from missing residues in X-ray crystallographic structures and flexible regions in NMR structures.
Sources: en.wikipedia.org
Selank is a synthetic seven-amino-acid peptide modeled on tuftsin, a fragment of the immunoglobulin G heavy chain. It was designed in Russia to combine anxiolytic and immunomodulatory properties in one molecule.
The first four residues of Selank reproduce the tuftsin sequence Thr-Lys-Pro-Arg. A Pro-Gly-Pro extension at the C-terminus was added to slow enzymatic breakdown and extend residence time.
It holds marketing authorization in Russia, where nasal drop formulations are sold. No equivalent approval exists in the European Union, the United States, or most other countries.
Reverse-phase HPLC is the usual method and gives a percentage purity value. Mass spectrometry then confirms the molecular mass. Together they provide a basic identity and purity profile for a lot.