This is a working overview of Intranasal delivery, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-03-08 and is reviewed periodically as new material appears.
Naming for this compound is not fully standardised in English sources. The spelling Selanc appears in some transliterations, and catalogue entries may instead list the peptide sequence itself as the identifier. Reference material sometimes groups it with other short synthetic peptides studied for behavioural effects, which can create confusion when citations are compared. Distinguishing the exact sequence from related tuftsin analogues is therefore a practical first step when reviewing any dataset or specification sheet.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, frequently abbreviated as TKPRPGP. It was designed as a structural analogue of tuftsin, a naturally occurring tetrapeptide released by enzymatic cleavage of the immunoglobulin heavy chain. The two additional proline residues at the C-terminal end extend the parent chain and change how the molecule behaves in solution. The free peptide has a calculated molecular mass of approximately 751.9 g/mol and is generally supplied as a lyophilised white to off-white powder.
Development work on the compound began in the 1980s and 1990s at the Institute of Molecular Genetics in Moscow, within the same research programme that produced the peptide Semax. Early investigators sought a tuftsin derivative with improved resistance to enzymatic breakdown and with activity in the central nervous system after peripheral administration. Most of the primary literature from this period was published in Russian, a factor that still shapes how easily the findings can be checked by outside groups.
Reversed-phase high-performance liquid chromatography is the standard technique for estimating peptide purity. The result is a peak-area percentage, which describes how much of the detected material elutes as the main peak in one run. Mass spectrometry confirms the molecular mass and can reveal truncated, adducted, or otherwise modified species. Amino acid analysis or tandem mass spectrometry can address sequence fidelity when identity is in doubt. None of these measurements, taken alone, establishes that a sample is fit for any specific purpose.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Tuftsin analogue |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form: TKPRPGP |
| Molecular formula | C33H57N11O9 | Calculated for the free peptide |
| Molecular weight | About 751.9 g/mol | Derived from the sequence |
| Appearance | White to off-white powder | Typical lyophilised form |
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.
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.
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.
=== Financial markets and housing === Oil prices did not experience a surge, which had been normal with previous conflicts in oil-producing regions; prices increased 1% as of 5 January 2026. The reason is believed to be that Venezuela only represents 1% of the global oil supply and high oil production by other producers, including the United States, Saudi Arabia, and Brazil. The stock prices of companies that could become involved in Venezuela without spending money, such as oilfield service companies SLB and Halliburton, and refiners Valero Energy and Marathon Petroleum, surged on 5 January 2026. Some oil companies also saw increases, such as ExxonMobil and ConocoPhillips. Bonds issued by the Venezuelan government and the state oil company PDVSA surged by 30%. Venezuela's bonds went into default in 2017 and doubled in price during the escalating tensions in 2025. Housing prices in Caracas rose from 20% to 50%. In touristic sites like Margarita Island the housing prices rose up to 80%. Some listing were paused waiting for a stabilization of the economy.
== Further reading == Slater, Anna G.; Cooper, Andrew I. (2015-05-29). "Function-led design of new porous materials". Science. 348 (6238) aaa8075. doi:10.1126/science.aaa8075. PMID 26023142. Satoh, Yusuke; Matsuno, Hirohiko; Yamamato, Takuya; Tajima, Kenji; Isono, Takuya; Satoh, Toshifumi (2017). "Synthesis of Well-Defined Three- and Four-Armed Cage-Shaped Polymers via "Topological Conversion" from Trefoil- and Quatrefoil-Shaped Polymers". Macromolecules. 50 (1): 97–106. Bibcode:2017MaMol..50...97S. doi:10.1021/acs.macromol.6b02316. Mato, Yoshinobu; Honda, Kohei; Tajima, Kenji; Yamamato, Takuya; Isono, Takuya; Satoh, Toshifumi (2019). "A versatile synthetic strategy for macromolecular cages: intramolecular consecutive cyclization of star-shaped polymers". Chemical Science. 10 (2): 440–446. doi:10.1039/C8SC04006K. PMC 6335864. PMID 30746091. Lee, Taeheon; Oh, Joongsuk; Jeong, Jonghwa; Jung, Haeji; Huh, June; Chang, Taihyun; Paik, Hyun-jong (2016-05-24). "Figure-Eight-Shaped and Cage-Shaped Cyclic Polystyrenes". Macromolecules. 49 (10): 3672–3680. Bibcode:2016MaMol..49.3672L. doi:10.1021/acs.macromol.6b00093. ISSN 0024-9297.
To promote weight gain and muscle growth As an adjunct in the treatment of bone pain and decreased bone strength associated with osteoporosis As an adjunct for catabolic states such as corticosteroid therapy and convalescence as in chronic infections, extensive surgery, and severe trauma To treat treatment-refractory anemias (via stimulation of erythropoiesis) such as acquired and congenital aplastic anemia and anemia of chronic kidney disease As an adjunct to improve strength and well-being in arthritis To treat short stature in youth
9 January – Séamus Begley, 73, traditional musician and singer. 16 January Carrie Acheson, 88, politician, TD (1981–1982). Joe Martin, 91, footballer (Dundalk, League of Ireland XI). 18 January – John L. Murray, 79, jurist, chief justice (2004–2011), judge of the Supreme Court (1999–2015) and the ECJ (1992–1999). 19 January Bertie Cunningham, 83, Gaelic footballer (Ballivor, Meath senior team). Peter Thomas, 78, footballer (Waterford, Galway United, national team). Born in England. 20 January – Pierce Higgins, 45, hurler (Tooreen, Ballyhaunis, Mayo senior team), motor neuron disease. 21 January – Micheál Mac Gréil, 91, Jesuit priest, sociologist and writer. 30 January – Eddie Spence, 97, Gaelic footballer (Belfast O'Connell's, Antrim senior team). Born in Northern Ireland. 31 January – Donie Hanlon, 85, Gaelic footballer (Gracefield, Offaly senior team).
== M == Magnetic resonance imaging (MRI) A non-invasive imaging technique that uses magnetic fields and radio waves to visualize detailed structures of the brain and other tissues. Malleus One of the three auditory ossicles in the middle ear. It transmits sound vibrations from the eardrum to the incus. Mammillary bodies Small round structures located in the hypothalamus involved in memory processing. Often damaged in Korsakoff syndrome. MAPK/ERK pathway A cellular signaling cascade involved in growth, differentiation, and survival. It plays roles in synaptic plasticity and neurodegeneration. Medial geniculate nucleus A relay center in the thalamus for auditory information, sending signals from the inner ear to the auditory cortex. Medial longitudinal fasciculus A bundle of nerve fibers in the brainstem involved in coordinating eye movements and head motion, especially during the vestibulo-ocular reflex. Medulla oblongata The lower part of the brainstem, responsible for autonomic functions such as respiration, heart rate, and blood pressure. Melatonin A hormone produced by the pineal gland that regulates circadian rhythms and the sleep–wake cycle. Secretion is influenced by light exposure. Memory The mental capacity to encode, store, and retrieve information. Subtypes include working memory, short-term memory, and long-term memory. Meninges The three protective membranes—dura mater, arachnoid mater, and pia mater—that surround the brain and spinal cord. Merkel cell A mechanoreceptor found in the skin involved in the sense of touch, particularly pressure and texture.
Sources: en.wikipedia.org
xv. ISBN 978-1-62683-043-1. Retrieved March 22, 2021. Siddiqi, Asif A. (2000). Challenge to Apollo: the Soviet Union and the space race, 1945–1974 (PDF). Washington, D.C.: National Aeronautics and Space Administration, NASA History Div. Retrieved February 10, 2026. Siddiqi, Asif A. (2003). Sputnik and the Soviet Space Challenge. Gainesville: University Press of Florida. ISBN 0-8130-2627-X. Siddiqi, Asif A. (2003). The Soviet Space Race with Apollo. Gainesville: University Press of Florida. ISBN 0-8130-2628-8. Stocker, Jeremy (2004). Britain and Ballistic Missile Defence, 1942–2002. London: Frank Case. pp. 12–24. ISBN 0-7146-5696-8. Swenson, Loyd S. Jr.; Grimwood, James M.; Alexander, Charles C. (1966). This New Ocean: A History of Project Mercury. NASA. ISBN 1-934941-87-5. Retrieved January 8, 2023. Turnhill, Reginald (2004). The Moonlandings: An Eyewitness Account. New York: Cambridge University Press. ISBN 0-521-81595-9. Pervushin, Anton (2011). 108 minutes which changed the world (in Russian). Эксмо. ISBN 978-5-699-48001-2.
Developments in science and technology have played a significant role in Pakistan's infrastructure, linking the nation to the global community. Each year, the Pakistan Academy of Sciences and the government invite scientists worldwide to the International Nathiagali Summer College on Physics. In 2005, Pakistan hosted an international seminar on "Physics in Developing Countries" for the International Year of Physics. Pakistani theoretical physicist Abdus Salam won a Nobel Prize in Physics for his work on the electroweak interaction. Pakistani scientists have made notable contributions in mathematics, biology, economics, computer science, and genetics. In chemistry, Salimuzzaman Siddiqui identified the medicinal properties of the neem tree's components. Ayub K. Ommaya developed the Ommaya reservoir for treating brain conditions. Scientific research is integral to Pakistani universities, national laboratories, science parks, and the industry. Abdul Qadeer Khan spearheaded Pakistan's HEU-based gas-centrifuge uranium enrichment program for its atomic bomb project. He established the Kahuta Research Laboratories (KRL) in 1976, serving as both its senior scientist and the Director-General until his retirement in 2001. Besides atomic bomb project, he made significant contributions in molecular morphology, physical martensite, and their applications in condensed and material physics. In 2023, Pakistan ranked 26th globally in published scientific papers. The influential Pakistan Academy of Sciences guides the government on science policies.
Alfatradiol (17α-estradiol) is distinguished from estradiol (17β-estradiol), the predominant sex hormone in females, only by the stereochemistry of the carbon atom 17. In contrast to 17β-estradiol, 17α-estradiol, while it still binds to the estrogen receptor, has less or no feminizing estrogenic activity depending on its dosage and the tissue it is affecting. Alfatradiol acts as an inhibitor of the enzyme 5α-reductase, which is responsible for the activation of testosterone to dihydrotestosterone, and which plays a role in regulating hair growth. 17α-Estradiol has been studied as a therapeutic with potential to treat Alzheimer's and Parkinson's disease and other patients with neurodegenerative diseases. 17α-Estradiol (as the sodium salt of its sulfated form) is a minor component (<10%) of historical hormone replacement products (such as conjugated estrogens, brand name Premarin), which have been studied and/or marketed in women and men since the 1930s. A survey of the effects of various forms of 17α-estradiol in humans on biochemical parameters, efficacy, estrogenicity, metabolism, safety, and tolerability has been published. Alfatradiol binds to the ERα and ERβ with 58% and 11% of the relative binding affinity of 17β-estradiol. However, it has 100-fold lower estrogenic activity relative to estradiol. On the other hand, alfatradiol has been found to bind to and activate the brain-expressed ER-X with a greater potency than estradiol, indicating that it may be the predominant endogenous ligand for the receptor.
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Sources: en.wikipedia.org
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, commonly written as TKPRPGP. It shares the first four residues with tuftsin and carries three prolines in the chain. The proline-rich tail is the main structural feature that separates it from the parent tetrapeptide.
Selank is a synthetic analogue built on the tuftsin tetrapeptide Thr-Lys-Pro-Arg. Extra proline residues were added to the C-terminus during design work. That modification is intended to make the peptide less vulnerable to rapid enzymatic degradation.
Transliteration from Russian produces variant spellings such as Selanc. Many suppliers avoid the trade-style name entirely and list the peptide sequence. Comparing sequences rather than names is the reliable way to confirm two entries describe the same molecule.
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.