Everything below concerns Intranasal delivery. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-05-03. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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 |
|---|---|---|
| Common route | Intranasal | Also injected in some animal work |
| Solubility class | Freely soluble in water | Solid form is hygroscopic |
| Typical storage | About -20 degrees Celsius | Keep desiccated and dark |
| Purity method | Reverse-phase HPLC | Reported as area percent |
| Confirmatory method | Mass spectrometry | Verifies expected molecular mass |
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.
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.
Handling follows standard practice for research peptides. Material is weighed in a low-humidity environment because the powder absorbs atmospheric moisture. Purity is reported as the percentage area of the main peak in a chromatogram, with specifications commonly set at 95 percent or higher; values below that threshold indicate the presence of truncated or modified species. Residual trifluoroacetate from purification is often present and may affect mass balance. Certificates of analysis should state the analytical method, the column and gradient used, and the lot-specific retention time so that results can be compared across suppliers.
Identity and purity of selank are established with reversed-phase high-performance liquid chromatography coupled to mass spectrometry. The peptide elutes from C18 columns with acetonitrile gradients in water containing trifluoroacetic acid or formic acid, and detection is usually performed by ultraviolet absorbance near 214 nm. Electrospray ionization in positive mode gives a doubly protonated ion near m/z 377, consistent with a mass of about 752 Da. Amino acid analysis or tandem mass spectrometry of fragment ions confirms the sequence. Because the molecule has no aromatic residues, it lacks a usable 280 nm chromophore, so low-wavelength detection or mass spectrometry is required.
Peptide bonds in selank are susceptible to hydrolysis under strongly acidic or basic conditions, and the terminal proline residues are vulnerable to exopeptidase activity in biological samples. Lyophilized powder stored dry at -20 °C typically remains stable for extended periods, whereas aqueous solutions degrade faster and may lose measurable purity within days to weeks depending on pH, temperature, and microbial load. Repeated freeze-thaw cycles promote aggregation and adsorption to container surfaces. For analytical work, solutions are usually prepared fresh, kept cold, and used within a single working day.
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.
Proposed mechanisms centre on the GABAergic system. Animal and tissue studies report changes in GABA-A receptor expression and reduced activity of GABA transaminase, the enzyme that degrades GABA. Effects on monoamine turnover, including serotonin and dopamine pathways, are also described, and a separate line of work links the peptide to increased expression of brain-derived neurotrophic factor in hippocampal tissue. Most of these findings come from rodent models and cell preparations. How the individual observations combine into a single coherent mode of action is not settled.
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.
Mueller–Hinton agar is a type of growth medium used in microbiology to culture bacterial isolates and test their susceptibility to antibiotics. This medium was first developed in 1941 by John Howard Mueller and Jane Hinton, who were microbiologists working at Harvard University. However, Mueller–Hinton agar is made up of a couple of components, including beef extract, acid hydrolysate of casein, and starch, as well as agar to solidify the mixture. The composition of Mueller–Hinton agar can vary depending on the manufacturer and the intended use, but the medium is generally nutrient-rich and free of inhibitors that could interfere with bacterial growth.
==== Post-traumatic growth ==== Posttraumatic growth (PTG) is a possible outcome after a traumatic event, besides posttraumatic stress disorder (PTSD). Following a traumatic event, for instance rape, incest, cancer, attack, or combat, "it is normal to experience debilitating symptoms of depression and anxiety." A person who shows PTG however, will experience these negative outcomes for a time and then show an increase in well-being, higher than it was before the trauma occurred. Martin Seligman, a founder of positive psychology, emphasizes that "arriving at a higher level of psychological functioning than before" is a key point in PTG. If instead an individual experiences a depressive period but recovers from an incident and returns to their normal level of psychological functioning, they are demonstrating resilience. This suggests that in PTG, the trauma acts as a turning point for the person to achieve greater well-being. Seligman recognizes "the fact that trauma often sets the stage for growth" and given the right tools, individuals can make the most of that opportunity." When reflecting on a traumatic growth, Seligman suggests using the following five elements to facilitate PTG: understand the response to trauma, reduce anxiety, utilize constructive disclosure, create a trauma narrative, and articulate life principles and stances that are more robust to challenge.
=== Biological strategies === It has become possible to accelerate natural aerobic, anaerobic, and sequential aerobic and/or anaerobic biological processes to minimize the presence of NAPLs in the subsurface environment. Most bioremediation strategies rely on the presence of specific populations of bacteria/microorganisms and the addition of organic carbon to stimulate biodegradation. This organic carbon can be supplied via injection of soluble organic carbon sources such as lactate, alcohols, cheese whey, etc. and placement of slow-release electron donors such as vegetable oil and soybean oil emulsions. Sufficient dissolved oxygen must be present for aerobic biodegradation, which can be supplied through strategies including air sparging and SVE. That said, the ability to supply sufficient oxygen is a limiting factor affecting the success of this type of remediation strategy. Also, many cases require the presence of inducers such as methane, propane, ammonia, or toluene, which are contaminants in and of themselves that are inherently harmful to the subsurface environment. Yet another challenge is maintaining a sufficient population of bacteria/microorganisms in the face of competition from native bacteria and other external pressures. There is also regulatory pushback to the use of genetically modified bacteria. Furthermore, NAPLs may not be readily bioavailable, limiting the effectiveness of biodegradation strategies. In this sense, biodegradation may not be appropriate as a single solution, but it can certainly be used in conjunction with other strategies.
== Function == Urocortin (UCN) II, also known as stresscopin-related peptide, is a 38 amino acid member of the mammalian corticotropin-releasing hormone (CRH) peptide family, which also includes CRH, UCN I, and UCN III. CRH mainly binds to type 1 CRH receptors (CRH1), while UCN II and III bind primarily to type 2 CRH receptors, and UCN I binds to both (CRH2). Each of these hormones has distinctive distribution patterns in the central nervous system and the periphery, suggesting each peptide may have distinct behavioral and physiological effects, although all have been associated with anxiety. In general, agonism of CRH1 receptors is posited to be anxiogenic and agonism of CRH2 receptors is posited to be anxiolytic. Urocortin II has been shown to have anorexigenic effects and hypotensive effects similar to Urocortin, but does not induce secretion of ACTH.
=== See also === Gary Lewis & the Playboys were a contemporary group founded and led by Gary Lewis, the son of Dean Martin's erstwhile comedy partner Jerry Lewis. With a sound likewise influenced by the British Invasion, their version of "This Diamond Ring" reached No. 1 in February 1965.
Sources: en.wikipedia.org
Formation of Compound I: APX reacts with H2O2 to form Compound I - where the heme is oxidized to Fe4+ = O (oxyferryl). This produces a porphyrin pi-organic cation radical. APX + H2O2 → Compound I + H2O [1] Formation of Compound II: Through a one electron reduction, Compound I is reduced by substrate (HS) to form Compound II; Compound II accepts a second electron from ascorbate to regenerate the ferric resting state. This is s sequential single-electron transfer steps. Compound I + HS → Compound II + S• [2] Compound II + HS → APX + S• + H2O [3] In ascorbate peroxidase, Compound I is a transient (green) species and contains a high-valent iron species (known as ferryl heme, FeIV) and a porphyrin pi-cation radical, as found in horseradish peroxidase. Compound II contains only the ferryl heme. Spectroscopic and kinetic work on plant APXs supports these intermediates and sequential one electron transfers.
Jean-Louis Sebagh is an Algerian-born French cosmetic surgeon and doctor who is known for his anti-aging surgeries, and use of botox, collagen and vitamin injections specifically on the face and neck. Sebagh's high profile clients including numerous celebrities, models and socialites include Cindy Crawford, Elle McPherson and Kylie Minogue. and he has offices in Paris and London.
Despite this, modern technology is increasingly reliant on deep, domain-specific scientific knowledge. In 1975, there was an average of one citation of scientific literature in every three patents granted in the U.S.; by 1989, this increased to an average of one citation per patent. The average was skewed upwards by patents related to the pharmaceutical industry, chemistry, and electronics. A 2021 analysis shows that patents that are based on scientific discoveries are on average 26% more valuable than equivalent non-science-based patents.
ISBN 978-1-903900-36-9. De Smet, Daniel (2017). "Ḥamza b. ʿAlī". In Fleet, Kate; Krämer, Gudrun; Matringe, Denis; Nawas, John; Rowson, Everett (eds.). Encyclopaedia of Islam (3rd ed.). Brill Online. ISSN 1873-9830. Emmett, Chad F. (1995). Beyond the basilica: Christians and Muslims in Nazareth. Chicago: University of Chicago Press. ISBN 0-226-20711-0. OCLC 30735259. Fawaz, L. T. (1994). An Occasion for War: Civil Conflict in Lebanon and Damascus in 1860. University of California Press. ISBN 978-0-520-08782-8. Firro, Kais (1992). A History of the Druzes. Vol. 1. BRILL. ISBN 90-04-09437-7. Halm, Heinz (2003). Die Kalifen von Kairo: Die Fāṭimiden in Ägypten, 973–1074 [The Caliphs of Cairo: The Fatimids in Egypt, 973–1074] (in German). Munich: C. H. Beck. ISBN 3-406-48654-1. Harris, William (2012). Lebanon: A History, 600-2011. Oxford University Press. ISBN 978-0-19-518111-1. Hartal, Moshe (2006). Dar, Shimon; Hartal, Moshe; Ayalon, E. (eds.). Rafid on the Golan: A Profile of a Late Roman and Byzantine Village. British Archaeological Reports International Series 1555. Oxford: Archaeopress. ISBN 1-84171-984-6.(registration required) Hazran, Yusri (2014). The Druze Community and the Lebanese State: Between Confrontation and Reconciliation. London and New York: Routledge. ISBN 978-0-415-72549-1. Hitti, Philip Khūri (1924). Origins of the Druze People and Religion. Forgotten Books. ISBN 978-1-60506-068-2. Retrieved 4 April 2012. {{cite book}}: ISBN / Date incompatibility (help) Heras, Nicholas A. (June 2014). "A Profile of Syria's Strategic Dar'a Province". CTC Sentinel. 7 (6).
The "war on drugs" thus brought with it a shift from reliance on imported supplies to domestic cultivation, particularly in Hawaii and California. Beginning in 1982, the Drug Enforcement Administration turned increased attention to marijuana farms in the United States, and there was a shift to the indoor growing of plants specially developed for small size and high yield. After over a decade of decreasing use, marijuana smoking began an upward trend once more in the early 1990s, especially among teenagers, but by the end of the decade this upswing had leveled off well below former peaks of use.
Sources: en.wikipedia.org
Most published work uses intranasal application, either as drops or as a nasal spray. Injection routes appear in a smaller set of animal experiments. Oral use is uncommon in the literature because peptide breakdown and poor absorption limit this route.
Reported human trials are few, brief and originate mainly from one country. They describe effects on anxiety-related measures, but sample sizes are small and reporting is limited. The results are widely regarded as preliminary rather than confirmed.
Reverse-phase liquid chromatography is used to assess purity and separation of related impurities. Mass spectrometry confirms that the observed molecular mass matches the expected peptide. A certificate of analysis from the supplier is the usual document of record.
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.