Everything below concerns Lyophilized powder. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2025-10-27. Numbers and descriptions here follow the published literature rather than marketing material.
Regulatory status differs sharply between jurisdictions. In Russia the peptide is registered as a prescription nasal preparation, while agencies such as the United States Food and Drug Administration have not approved it for any indication. Products sold elsewhere are typically labeled for laboratory research only, and such labels shift responsibility for safe handling to the purchaser. Because the same name covers pharmaceutical-grade nasal drops and bulk research powder, identity and purity documentation becomes the main practical concern when comparing sources.
Semax is a synthetic seven-amino-acid peptide whose sequence extends the ACTH(4-10) fragment with a C-terminal proline-glycine-proline tripeptide. The commonly cited sequence is Met-Glu-His-Phe-Pro-Gly-Pro, giving a molecular formula near C37H51N9O10S and a molecular weight close to 813.9 g/mol. It belongs to the broader class of synthetic ACTH fragments studied for central nervous system effects rather than for adrenal steroid stimulation. In practice the material appears as a lyophilized white powder for laboratory work or as a dilute saline solution in clinical settings.
Development is attributed to researchers at the Institute of Molecular Genetics in Moscow during the early 1980s, building on earlier Soviet work with ACTH fragments. Russian regulatory approval followed for intranasal use, and the compound has remained commercially available there for decades. Most published human data originate from Russian and, later, some Eastern European clinical reports, which are not always accessible in English translation. Outside that region the material is generally handled as a research chemical rather than a licensed medicine.
Practical handling follows from those properties. Bulk material is best divided into single-use portions soon after receipt, because each thaw exposes the whole container to moisture and temperature cycling. Vials should be allowed to reach room temperature before opening to prevent condensation on the powder. Low-binding plasticware reduces loss of dilute solutions, and sterile filtration is used when a preparation must remain free of microbial growth. Records of batch number, reconstitution date and storage history are what allow a later analytical result to be interpreted meaningfully.
Identity and purity of Semax are established mainly by reversed-phase high-performance liquid chromatography coupled with mass spectrometry. The chromatographic trace gives a purity estimate as a percentage of total peak area, while electrospray or matrix-assisted laser desorption ionization confirms the molecular mass against the calculated value. Amino acid analysis and sequence-specific fragmentation provide further confirmation when a supplier's chain of custody is unclear. Vendors frequently quote a purity figure without stating the detection wavelength or the integration method, which limits how far one number can be compared with another.
Stability depends heavily on physical state. Lyophilized powder held dry, cold and dark retains its content over long periods, whereas dissolved peptide begins to change within days at room temperature. The most cited degradation route is oxidation of the methionine residue, which converts the peptide to a sulfoxide form that elutes differently on chromatography. Hydrolysis of amide bonds and adsorption onto container walls contribute smaller losses. Buffers that exclude oxygen from the headspace slow the oxidation pathway, but no single condition prevents all change indefinitely.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide (ACTH fragment analog) | Not a steroid; does not belong to the melanocortin agonist drugs by marketing category |
| Molecular formula | C37H51N9O10S (commonly cited) | Reported values vary slightly with salt and counter-ion content |
| Appearance | White to off-white lyophilized powder | A single batch may appear as a loose cake or fluffy solid |
| Solubility | Freely soluble in water and aqueous buffer | Stock solutions are usually prepared in sterile water or saline |
| Typical storage | −20 °C or below, desiccated and protected from light | Seal opened vials promptly to limit moisture uptake |
Development of the compound took place in the Soviet Union during the 1980s, largely through peptide research groups affiliated with the Shemyakin-Ovchinnikov Institute and Moscow State University. Investigators screened fragments of adrenocorticotropic hormone for activity on the central nervous system while attempting to separate cognitive effects from hormonal ones. The shortened sequence was selected because it retained behavioral activity in animal models without stimulating corticosteroid release. Early publications described the molecule as an ACTH(4-10) analog.
Published research on this peptide originates mainly from Russian laboratories, and the wider international literature is comparatively thin. Studies have used rodent models of stroke, hypoxia, and memory tasks, with a smaller number of human trials reported. Reported outcomes include changes in attention and memory measures, along with effects on neurotrophic factor expression in some experiments. Small sample sizes, inconsistent dosing protocols, and limited independent replication are widely noted limitations, so the strength of the clinical evidence remains an open question.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. The first four residues correspond to the ACTH(4-10) fragment, while the terminal Pro-Gly-Pro extension was added to improve metabolic stability. Its molecular formula is C37H51N9O10S and its monoisotopic mass is approximately 813.9 Da. The compound is classified as a peptide research chemical and as a registered pharmaceutical product in Russia, but it does not hold marketing approval in the European Union or the United States. Naming conventions vary across supplier catalogs.
Lyophilized material is chemically stable for extended periods when kept dry, cold, and protected from light. The powder is hygroscopic, so vials should be warmed to room temperature before opening to reduce condensation on the contents. Once dissolved, the peptide is far less stable because peptide bonds are susceptible to hydrolysis and the methionine residue can oxidize. Solutions are typically aliquoted and held at 2-8 °C for short intervals or frozen for longer ones, and repeated freeze-thaw cycles should be avoided.
Routine characterization relies on reversed-phase high-performance liquid chromatography to establish purity and on mass spectrometry to confirm molecular identity. Electrospray ionization and matrix-assisted laser desorption ionization are both used for mass verification. Amino acid analysis and peptide mapping can detect sequence errors. Common impurities include truncated sequences, methionine sulfoxide formed by oxidation, and deamidated products. Chromatograms are usually recorded near 214 nm, where the peptide backbone absorbs, and purity is reported as the percentage area of the principal peak.
Semax is a synthetic heptapeptide developed in the Soviet Union during the 1980s by researchers at the Institute of Molecular Genetics in Moscow. It was designed as a truncated analog of adrenocorticotropic hormone, retaining only the fragment spanning residues four through ten. Investigators sought a peptide that would preserve the cognitive effects associated with ACTH while eliminating the hormonal stimulation of the adrenal cortex. The compound entered clinical use in Russia during the following decade.
Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead as a research chemical.
Later generations of the molecule include an N-acetylated form and an amidated form, both marketed online alongside the parent peptide. These variants differ in terminal chemistry and stability, and they are frequently discussed in the same breath even though they have not been compared in controlled trials. Supply outside formal healthcare systems comes largely from laboratories that synthesize peptides to order. Purity and identity of these materials vary widely, and no single body oversees the international trade.
Published studies are dominated by animal models of stroke, ischemia, and cognitive impairment, with a smaller number of human trials conducted in Russia. Many of the human reports are small, single-center, and published in Russian-language journals, which limits independent scrutiny. Outcome measures vary between studies and often rely on clinician-rated scales rather than objective biomarkers. Systematic reviews have noted the methodological weaknesses and called for larger, preregistered trials before firm conclusions can be drawn.
Claims about enhanced focus, memory, or mood in healthy people rest mostly on anecdotal reports and community discussion rather than on controlled data. It remains unclear whether any cognitive benefit observed in patients recovering from brain injury would extend to uninjured users. Dose-response relationships, long-term safety, and interactions with other drugs are not well characterized in the peer-reviewed literature. Questions about optimal route of administration and treatment duration likewise remain open.
Polyhistidine tags most commonly consist of six histidine residues. Tags with up to twelve histidine residues or dual tags attached via short linker are not uncommon though and may improve purification results by enhancing binding to the affinity resin, allowing for increased stringency of washing and separation from endogenous proteins. The tag can be added to a gene of interest using methods common to most purification tags. The most basic method is to subclone the gene of interest into a vector containing a polyhistidine tag sequence. Many vectors for use with various expression systems are available with polyhistidine tags in a variety of positions and with differing protease cleavage sites, other tags etc. However, if an appropriate vector is unavailable or the tag needs to be inserted at a location other than the proteins N- or C-terminus, the gene of interest can be either directly synthesised containing a polyhistidine tag sequence or various methods based on PCR can be used to add the tag to a gene. A common approach is to add the coding sequence for the polyhistidine tag to the PCR primers as an overhang.
=== Arnold Adolph Berthold (1849) === Arnold Adolph Berthold was a German physiologist and zoologist, who, in 1849, had a question about the function of the testes. He noticed in castrated roosters that they did not have the same sexual behaviors as roosters with their testes intact. He decided to run an experiment on male roosters to examine this phenomenon. He kept a group of roosters with their testes intact, and saw that they had normally sized wattles and combs (secondary sexual organs), a normal crow, and normal sexual and aggressive behaviors. He also had a group with their testes surgically removed, and noticed that their secondary sexual organs were decreased in size, had a weak crow, did not have sexual attraction towards females, and were not aggressive. He realized that this organ was essential for these behaviors, but he did not know how. To test this further, he removed one testis and placed it in the abdominal cavity. The roosters acted and had normal physical anatomy. He was able to see that the location of the testes does not matter. He then wanted to see if it was a genetic factor that was involved in the testes that provided these functions. He transplanted a testis from another rooster to a rooster with one testis removed, and saw that they had normal behavior and physical anatomy as well. Berthold determined that the location or genetic factors of the testes do not matter in relation to sexual organs and behaviors, but that some chemical in the testes is being secreted is causing this phenomenon.
=== Europe === The U.S. market is being eclipsed by booming demand for cocaine in Europe, where users now pay twice the going U.S. rate. In 2008, U.S. Attorney General Michael Mukasey announced that an international drug interdiction operation, Project Reckoning, involving law enforcement in the United States, Italy, Canada, Mexico and Guatemala had netted more than 500 organized crime members involved in the cocaine trade. The announcement highlighted the Italian-Mexican cocaine connection. Concerns about European security and the trafficking of drugs through the European continent have grown in recent years, and, in December 2022, Europol and the DEA released a joint report on the situation involving Mexican drug trafficking through the EU. In December 2011, the government of Spain remarked that Mexican cartels had multiplied their operations in that country, becoming the main entry point of cocaine into Europe. In 2012, it was reported that Mexican cartels had joined forces with the Sicilian Mafia, when Italian officials unearthed information that Palermo's black market, along with other Italian ports, was used by Mexico's drug cartels as a conduit to bring drugs to the European market, in which they had been trafficking drugs, particularly cocaine, throughout the Atlantic Ocean for over ten years to Europe.
The mostly studied system is yttrium (Y) fractionation between the phosphate monazite and the silicates garnet and xenotime. All three minerals preferentially fractionate Y, yet they form and break down at different stages of metamorphism. Xenotime has the highest fractionating power, then garnet and then monazite. In a simplified case of a clockwise P-T path involving garnet and monazite, garnet grows along a prograde path with Y continuously being incorporated, thus the Y content in monazite formed at this stage (prograde) should decrease progressively with higher grade. However, as temperature increases to a certain point, partial melting (anatectic) of monazite occurs around its rim, releasing Y into the melts. As the system later cools and melt crystallizes, regrown monazite will have higher Y content. Partial melting usually happens during peak metamorphism (the highest temperature in a P-T path), but age and chemical information during this stage are not recorded since the monazite is melting. However, the ages of last prograde growth rim (lowest Y) and the first post-anatectic growth rim (highest Y) usually bracket the time of partial melting. Another scenario involves the formation or breakdown of garnet, influencing the Y and HREE (heavy rare earth elements) content in the environment, thus the content of growing monazite. Basically, monazites grown before garnet formation have a higher Y and HREE content than those formed during or after garnet formation.
== Chemistry == The medication is extracted from the stem of the pineapple plant (Ananas comosus) by a standardised process, and each lot has to be analysed for its chemical composition. It contains a mixture of proteolytic enzymes, the main compound being stem bromelain. Bromelain is thought to be the active ingredient, but this has not been determined in studies. The gel basis contains water, polyacrylic acid as a gelling agent, and a disodium hydrogen phosphate/sodium hydroxide buffer.
Sources: en.wikipedia.org
The online video platform TikTok has had worldwide a social, political, and cultural impact since its global launch in September 2016. The platform has rapidly grown its userbase since its launch and surpassed 2 billion downloads in October 2020. It became the world's most popular website, ahead of Google, for the year 2021.
Two-dimensional chromatography is a type of chromatographic technique in which the injected sample is separated by passing through two different separation stages. Two different chromatographic columns are connected in sequence, and the effluent from the first system is transferred onto the second column. Typically the second column has a different separation mechanism, so that bands that are poorly resolved from the first column may be completely separated in the second column. (For instance, a C18 reversed-phase chromatography column may be followed by a phenyl column.) Alternately, the two columns might run at different temperatures. During the second stage of separation the rate at which the separation occurs must be faster than the first stage, since there is still only a single detector. The plane surface is amenable to sequential development in two directions using two different solvents.
== V == vaccine – vacuole – varicella-zoster virus – vascular cambium – vascular tissue – vein – vertebrate – vesicle – vesicular stomatitis virus – vestibular system – vicariance – virology – viral classification – virus – viral evolution – viridamide – visible light – vision – vitamin - Viroid
In early 2008, Bush vowed full support for admitting Ukraine and Georgia into NATO despite Russia's opposition to the further enlargement of NATO. During the 2008 Russo-Georgian diplomatic crisis, Bush condemned Russia for recognizing the separatist government of South Ossetia. When Russian troops invaded Georgia later that summer, Bush said: "Bullying and intimidation are not acceptable ways to conduct foreign policy in the 21st century."
Sources: en.wikipedia.org
On May 30, 2024, Trump was found guilty by a jury of all 34 felony counts in The People of the State of New York v. Donald J. Trump. The jury found that Trump falsified business records relating to hush money payments made to pornographic film star Stormy Daniels to ensure her silence about a sexual encounter between them. This conviction made Trump the first former U.S. president to be convicted of a crime. On January 10, 2025, Trump was given a no-penalty sentence known as an unconditional discharge. Trump faced other criminal charges as well. In United States of America v. Donald J. Trump, Trump faced four criminal counts for his alleged role in attempting to overturn the 2020 United States presidential election and involvement in the January 6 United States Capitol attack; the case was dismissed following Trump's re-election in November 2024. In The State of Georgia v. Donald J. Trump, et al., Trump was charged with eight criminal counts for his alleged attempts to overturn the results of the 2020 United States presidential election in Georgia. District Attorney Fani Willis was disqualified from prosecuting the case; Willis has appealed that decision. In United States of America v. Donald J. Trump, Waltine Nauta, and Carlos De Oliveira, Trump faced 40 criminal counts relating to his hoarding of classified documents and alleged obstruction of efforts to retrieve them; the case was dismissed in July 2024. On May 9, 2023, in E. Jean Carroll v. Donald J.
=== Reasons for the development of multicellularity === Despite the fact that prokaryotic cells contained the building blocks required for multicellularity to arise, this transition did not occur for around 1500 million years after the origins of the first eukaryotic cell. Scientists have proposed two major theories for the reason that multicellularity arose so late after the appearance of life on Earth.
== Epidemiology == A 1994 community-based study indicated that two out of every 100,000 people with a sCSF, while a 2004 emergency room-based study indicated five per 100,000. sCSF leaks generally affect the young and middle aged; the average age for onset is 42.3 years, but onset can range from ages 22 to 61. In an 11-year study, women were found to be twice as likely to be affected as men. Studies have shown that sCSF leaks runs in families. It is suspected that genetic similarity in families includes weakness in the dura mater which leads to a sCSFL. Large scale population-based studies have not yet been conducted. While a majority of sCSF leaks continue to be undiagnosed or misdiagnosed, an actual increase in occurrence is unlikely.
Sources: en.wikipedia.org
It is a short synthetic peptide built from seven amino acids: methionine, glutamic acid, histidine, phenylalanine and three prolines. The sequence derives from the 4-10 fragment of adrenocorticotropic hormone with an added proline-glycine-proline tail. No plant or animal extract is involved; the material is produced by solid-phase peptide synthesis.
It was developed in the Soviet Union during the early 1980s by groups at the Institute of Molecular Genetics in Moscow. Russian approval for intranasal use followed, and it has been marketed there since. Western laboratories encountered it mainly through translated literature and, later, through online research-chemical trade.
It holds a Russian registration as a prescription nasal product but has no approval from the European Medicines Agency or the United States Food and Drug Administration. Buyers outside Russia usually receive material sold strictly for laboratory research. That distinction matters because research-grade and pharmaceutical-grade products carry different documentation and testing expectations.
Suppliers normally quote a percentage of total chromatographic peak area, most often from reversed-phase HPLC. That figure says nothing about what the remaining percentage contains, and it depends on the detection wavelength used. A mass spectrometry result is a separate and stronger check on identity.