Everything below concerns Intranasal delivery. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-01-09. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Measuring peptide exposure inside the brain is technically difficult. Selank is degraded rapidly in plasma, and assays must separate intact peptide from fragments, which favors targeted mass spectrometry over immunoassays alone. Reported half-lives are short, on the order of minutes, so effects observed hours later are attributed to downstream signaling rather than to the parent compound. Blood-brain barrier permeability is debated and rarely quantified directly. Gaps include absent dose-response characterization, inconsistent reporting of purity, and almost no pharmacokinetic data from human participants.
Selank is studied chiefly as an animal-model anxiolytic with proposed secondary effects on memory and immune signaling. Reported mechanisms include modulation of the GABA-A receptor complex, inhibition of enkephalin-degrading enzymes, and shifts in monoamine turnover within limbic structures. Some experiments describe increased expression of brain-derived neurotrophic factor in the hippocampus after repeated dosing. No single molecular target has been confirmed, and the peptide does not bind any receptor with the selectivity typical of a conventional small-molecule drug. Mechanism therefore remains a set of hypotheses rather than an established pathway.
| 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 |
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.
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.
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.
Reported activity for Selank centers on anxiolytic and nootropic effects. Russian clinical reports describe use in anxiety and in cognitive or attention-related complaints. Most of this evidence comes from studies conducted by the same research groups that developed the peptide. Independent replication in other countries remains limited, and no major Western regulatory agency has approved the compound for any indication. The gap between local reports and external verification is a recurring point in discussions of the peptide.
Lyophilized material is generally stable for extended periods when kept dry at or below minus twenty degrees Celsius. Working solutions are less stable, and common practice is to aliquot and freeze them so that repeated freeze-thaw cycles are avoided. Aqueous solutions are sensitive to pH extremes and to microbial growth, so short-term storage at refrigerator temperature is typical. Oxidation and hydrolysis are the principal degradation routes. Reconstitution with sterile water or a mild buffer is standard, and solutions should be protected from light.
Regulatory treatment varies by jurisdiction. In Russia the compound is a registered prescription product, while in the European Union and the United States it is generally handled as a research chemical without a marketing authorization. Suppliers therefore operate outside pharmaceutical oversight, and buyers rely on supplier documentation for purity and identity claims. Chain of custody and third-party testing are the main verification tools. Analysts note that the absence of a pharmacopoeial monograph for research-grade material limits standardization across vendors.
Purity assessment relies mainly on reverse-phase high-performance liquid chromatography with ultraviolet detection. Because the peptide lacks a strong chromophore, detection often uses backbone absorbance near 214 nm. Identity is confirmed by mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, comparing the measured mass against the expected value. Amino acid analysis can verify composition after acid hydrolysis. Diastereomer content and residual counterions are reported less often, although both can influence biological assays.
==== Mars ==== In 1964, NASA's Mariner 4 became the first successful Mars flyby, transmitting 21 pictures of the planets surface. This was followed by Mariner 6 and 7 in 1969 which completed the first dual mission to Mars in 1969.
Independent researchers estimate that between 300,000 and 500,000 civilians died during this period while the Bangladesh government puts the number of dead at three million, a figure now nearly universally regarded as excessively inflated. Some academics such as Rudolph Rummel and Rounaq Jahan say both sides committed genocide; others such as Richard Sisson and Leo E. Rose believe there was no genocide. In response to India's support for the insurgency in East Pakistan, preemptive strikes on India by Pakistan's air force, navy, and marines sparked a conventional war in 1971 that resulted in an Indian victory and East Pakistan gaining independence as Bangladesh. Yahya Khan was replaced by Zulfikar Ali Bhutto as president; the country worked towards promulgating its constitution and putting the country on the road to democracy. In 1972 Pakistan embarked on an ambitious plan to develop its nuclear deterrence capability with the goal of preventing any foreign invasion; the country's first nuclear power plant was inaugurated in that same year. India's first nuclear test in 1974 gave Pakistan additional justification to accelerate its nuclear program. Democracy ended with a military coup in 1977 against the leftist PPP, which saw General Zia-ul-Haq become the president in 1978. From 1977 to 1988, President Zia's corporatisation and economic Islamisation initiatives led to Pakistan becoming one of the fastest-growing economies in South Asia.
=== Possible expansion into other Latin American nations === In August of 2026, while visiting Panama, Hegseth proclaimed that the United States has made a military agreement with Colombia, Guatemala and Honduras to combat criminal drug organizations. Hegseth added that like the attacks on boats that the U.S. had been conducting in the East Pacific and the Caribbean, the attacks on drug traffickers on land would be the same. In addition, Hegseth stated that the U.S. would continue to pursue military cooperation with Ecuador. However, Guatemala later publicly repudiated Hegseth's claims.
== Occurrence in foods and beverages == 2,5-Diketopiperazines are often formed during cooking from naturally occurring oligopeptides in foodstuffs. They have been detected in foods such as stewed beef, beer, barley bread, Awamori, dark chocolate, coffee and Comté cheese. 2,5-diketopiperazines have been shown to be important sensory compounds that help to influence the taste of a food product. The proline derived 2,5-diketopiperazines are the most abundant and structurally diverse class of 2,5-diketopiperazines found in food. The valine derivative cyclo(L-Val-L-Pro) at a concentration of 1742 ppm, was identified as the most important bitter 2,5-diketopiperazine contributing to the bitter taste of roasted cocoa. It has also been found as one of the major 2,5-diketopiperazines in autolyzed yeast extract and stewed beef and is also present in chicken essence and coffee. It has also been isolated from a variety of marine microorganisms and has been identified as an active LasI quorum-sensing signal molecule important for the plant growth promotion by Pseudomonas aeruginosa. The most studied of all the simple 2,5-diketopiperazines is the histidyl-proline 2,5-diketopiperazine cyclo(L-His-L-Pro) which is found in a variety of foods, with particularly high concentrations in fish and fish products. It is well absorbed orally, and crosses the blood–brain barrier via a non-saturable mechanism.
== History == Etifoxine was developed by Hoechst in the 1960s. It was introduced for medical use in France in 1979. Since at least 2000, etifoxine has been marketed by the French pharmaceutical company Biocodex. Following reports of post-marketing toxicity, the safety of etifoxine was reassessed by the French government and the European Medicines Agency (EMA). In January 2022, the EMA "finalized its review of Stresam and concluded that the medicine can continue to be used for the treatment of anxiety disorders, but it must not be used in patients who previously had severe skin reactions or severe liver problems after taking etifoxine."
Sources: en.wikipedia.org
==== Novel agents ==== Several newer agents, including temozolomide and bendamustine, have activity in relapsed SCLC. Of note, temozolomide yielded a response rate of 38% for brain metastases due to SCLC. In a clinical trial of 50 patients, a combination of olaparib and temozolomide in relapsed small-cell lung cancer yielded an overall response rate of 41.7%, median progression-free survival of 4.2 months, and overall survival was 8.5 months. Lurbinectedin showed an increased overall survival rate in relapsed small cell lung cancer in a trial. Lurbinectedin is As of 2019 available in the U.S. under an expanded access program (EAP). Trilaciclib, a CKD4/6 inhibitor, reduces chemotherapy-induced toxicity in patients being treated for small-cell lung cancer. In 2021, the FDA approved trilaciclib (Cosela) as a treatment to reduce the frequency of chemotherapy-induced myelosuppression for patients receiving certain types of chemotherapy for extensive-stage small-cell lung cancer.
Representative Don Bacon became the first Republican House member to urge that Hegseth be fired. At least five political appointees within the Department of Defense resigned by April 24. That day, Joe Kesper, Hegseth's chief of staff, resigned, but stated that he would remain at the department as a special government employee. The firings and resignations led to a crisis within the Department of Defense that was described as a "free-for-all" by one employee who spoke to Politico.
Morgan State began playing football in 1898, 31 years after the school was founded. The Bears have won three MEAC Championships (1976, 1979 and 2014). Their last Division I-AA/FCS playoffs appearance was in 2014. Fifty-three former Morgan players have gone on to play professional football. Former Morgan Bears Len Ford, Leroy Kelly, Willie Lanier and Rosey Brown are members of the Pro Football Hall of Fame in Canton, Ohio.
== Principle of operation == The quadrupole consists of four parallel metal rods. Each opposing rod pair is connected together electrically, and a radio frequency (RF) voltage with a DC offset voltage is applied between one pair of rods and the other. Ions travel down the quadrupole between the rods. Only ions of a certain mass-to-charge ratio will reach the detector for a given ratio of voltages: other ions have unstable trajectories and will collide with the rods. This permits selection of an ion with a particular m/z or allows the operator to scan for a range of m/z-values by continuously varying the applied voltage. Mathematically this can be modeled with the help of the Mathieu differential equation.
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.
Intranasal administration predominates in both animal and human research because it avoids hepatic first-pass metabolism. Injectable and intraperitoneal routes appear in animal work mainly for comparison.