Everything below concerns mass spectrometry. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-06-24. Numbers and descriptions here follow the published literature rather than marketing material.
Once dissolved, the peptide is considerably less stable than the solid. Aqueous solutions are usually prepared at neutral to slightly acidic pH, filtered, and divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are a common cause of avoidable loss and are best prevented by never refreezing a thawed aliquot. Adsorption to plastic and glass surfaces can lower the measured concentration of dilute solutions, particularly below roughly 0.1 mg/mL. Buffer choice, salt content, and container material all influence how much peptide remains detectable after storage.
Identity and purity are established with standard peptide methods. Reversed-phase HPLC with ultraviolet detection near 214 nm resolves the parent peak from deletion and truncation byproducts, and reports typically quote a main-peak percentage. Mass spectrometry by electrospray or MALDI-TOF confirms the expected molecular mass, while amino acid analysis or peptide mapping can verify composition when the sequence itself is in question. A certificate of analysis that pairs a chromatogram with a mass spectrum is more informative than a purity figure alone. Counter-ion content and residual solvents are separate specifications and are frequently omitted.
Development took place during the 1980s at institutes of the Russian Academy of Sciences, where peptide fragments of ACTH were screened for cognitive and neuroprotective effects. The compound received regulatory approval in Russia as a nasal preparation, marketed for conditions such as ischemic stroke, transient ischemic attacks, and optic nerve disorders. Registration in other countries has not followed. Most published clinical reports originate from a small number of Russian research groups, and independent replication outside that setting remains limited. The regulatory status therefore differs sharply between Russia and the rest of the world.
Laboratory work points toward modulation of neurotrophic signaling, particularly expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal tissue. Studies also describe effects on monoamine turnover, inflammatory mediators, and oxidative markers. These observations come mainly from animal models and cultured cells, so the causal chain in humans is not firmly established. Whether the reported molecular changes translate into measurable clinical benefit is an open question. Reviews generally present the mechanism as plausible rather than demonstrated.
Clinical evidence consists largely of small trials with modest sample sizes, often without independent replication. Reported endpoints include cognitive scores, recovery after stroke, and visual function, but study designs vary widely and few trials meet contemporary reporting standards. Systematic reviewers have noted a high risk of bias in several of these reports. No large multicenter trial conducted outside Russia has been published. The compound is therefore best described as investigational in most jurisdictions, with its clinical role still unresolved.
| Property | Value | Notes |
|---|---|---|
| Solid storage temperature | -20 °C or below | Desiccated and protected from light |
| Solution storage temperature | -80 °C as single-use aliquots | Avoid repeated freeze-thaw cycles |
| Purity assessment method | RP-HPLC, around 214 nm | Reported as main-peak area percent |
| Identity confirmation method | ESI-MS or MALDI-TOF | Measured mass compared with calculated mass |
| Common synonyms | ACTH(4-10) analog; Met-Glu-His-Phe-Pro-Gly-Pro | Also written as Semaxum in some sources |
Published research covers ischemic stroke, traumatic brain injury, cognitive impairment, optic nerve conditions and attention-related measures. Much of the human evidence comes from small trials conducted in one country, which limits how far the results generalize. Animal models supply the larger share of the data, and effects seen in rodents do not transfer automatically to people. Reviews have noted that methodological reporting is often incomplete, making it difficult to pool results or compare treatment schedules across studies.
Pharmacokinetic accounts emphasize rapid breakdown. After intravenous dosing the intact peptide disappears from blood within minutes, and nasal delivery produces low but measurable concentrations. Metabolites rather than the parent molecule may account for part of the observed activity, although the relative contribution is unresolved. Dosing in the literature varies widely and no optimal schedule has been agreed. These gaps are regularly cited as a reason the findings have not produced broad clinical adoption beyond the original research setting.
Proposed mechanisms center on neurotrophic signaling rather than on classical melanocortin receptor activation. Rodent experiments have reported shifts in the expression of brain-derived neurotrophic factor and nerve growth factor after administration, together with changes in the associated receptor systems. Several authors argue that the peptide acts largely through its degradation products and their interaction with peptidergic pathways, but this remains a hypothesis rather than a settled finding. No single molecular target has been identified in a way that the field broadly accepts.
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.
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.
=== Backing fabrics === In these cases, a backing fabric can be used. Backing fabrics must be durable and able to withstand tensioned in order to offer support, but not so heavy that it causes strain on the original textile. The fabric should extend beyond the damaged areas in combination with appropriate stitching in weak areas when used in combination with local repairs and visual compensation techniques.
Oxford's Joint European Torus nuclear fusion laboratory conducts its final experiments after 40 years in operation. 15 October First Minister of Scotland Humza Yousaf signals a change in his party's Scottish independence strategy, now saying that an SNP win in a majority of Scotland's Westminster seats would give the party a mandate to begin independence negotiations with the Westminster Government. One person is killed and another is wounded in a stabbing attack in Hartlepool. The attack is being investigated by Counter Terrorism Policing. A suspect has been detained. 16–22 October – Storm Babet hits the UK, bringing disruption to much of the country. Red weather warnings are issued by the Met Office, as three deaths are reported, and power shortages affect tens of thousands in Scotland. The crew of a Danish fishing trawler are rescued by the RNLI in the North Sea. 16 October Prime Minister Rishi Sunak confirms that six British citizens were killed during the Hamas attacks on Israel, while a further ten are missing. Two British teenage sisters, Noya and Yahel Sharabi, are among those missing, and believed to have been kidnapped, following the 7 October attacks on Israel. Their mother, Lianne, also a British citizen, was killed in the Be'eri massacre. The following day the girls' family tells the BBC the Yahel was also murdered. On 22 October the family release a statement to say Noya was also murdered. Guardian cartoonist Steve Bell is sacked following a row over a drawing he created of Israeli prime minister Benjamin Netanyahu that was deemed to be antisemitic.
2019: New Zealand chemist Margaret Brimble is the first New Zealand woman to be inducted into the Division of Medicinal Chemistry of the American Chemical Society’s Hall of Fame. 2019: Malawian nurse and educator Address Malata is appointed as Vice-Chancellor of the Malawi University of Science and Technology (MUST), becoming the first Malawian women university Vice-Chancellor. 2019: American imaging scientist Katie Bouman developed an algorithm that made the first visualization of a black hole possible using the Event Horizon Telescope. She was part of the team of over 200 people who implemented the project.
Sources: en.wikipedia.org
Glycocyamine (or guanidinoacetate) is a metabolite of glycine in which the amino group has been converted into a guanidine by guanylation (transfer of a guanidine group from arginine). In vertebrate organism it is then transformed into creatine by methylation. Glycocyamine is used as a supplement and as a feed additive in poultry farming. However, the metabolism of creatine from glycocyamine in the liver causes a depletion of methyl groups. This causes homocysteine levels to rise, which has been shown to produce cardiovascular and skeletal problems. Glycocyamine plays a role in the metabolism of the amino acids serine, threonine, and proline.
The declaration's first safeguard clause referred to protecting the civil and religious rights of non-Jews in Palestine. The clause had been drafted together with the second safeguard by Leo Amery in consultation with Lord Milner, with the intention to "go a reasonable distance to meeting the objectors, both Jewish and pro-Arab, without impairing the substance of the proposed declaration". Arabs constituted around 90% of the population of Palestine, but – as stated by Ronald Storrs, Britain's Military Governor of Jerusalem between 1917 and 1920 – they were "not so much [named but] lumped together under the negative and humiliating definition of 'Non-Jewish Communities'". Additionally, there was no reference to protecting the political rights of this group, as there was regarding Jews in other countries. This lack of interest was frequently contrasted against the commitment to the Jewish community, with various terms used over subsequent years to regard the two obligations as linked. A heated question was whether the status of both groups had "equal weight", which the British government and the Permanent Mandates Commission held to be the case in the 1930 Passfield white paper. Balfour stated in February 1919 that Palestine was considered an exceptional case in which, referring to the local population, "we deliberately and rightly decline to accept the principle of self-determination," although he considered that the policy provided self-determination to Jews. Avi Shlaim considers this the declaration's "greatest contradiction".
Early European alchemists gave sulfur an alchemical symbol of a triangle atop a cross (🜍). Another type of sulfur mentioned in alchemy, black sulfur (sulfur nigrum), also had its own symbol combining a two-barred cross atop a lemniscate (🜏). This symbol was later used by Anton LaVey as a satanist symbol, the "Leviathan cross", as he associated it with the brimstone of Hell. This has led to some confusion and misconceptions about its original alchemical meaning: in alchemical texts, black sulfur was not a synonym for "brimstone" or an alternative symbol for sulfur as one of the Three Primes, but was instead considered a distinct type of sulfur, listed separately. Black sulfur, also known as grey sulfur (sulfur griseum) or "horse brimstone" (sulfur caballinum), was a grey, impure form of sulfur, usually the dregs of sulfur purification, which was used for medicinal purposes despite often containing arsenic. Iron shavings or hammerscale were sometimes added to it in its manufacture. The "horse" in the name is thought to reference its veterinary use: low quality sulfur, only fit to treat horses. In the 19th century, it was sometimes also sold under the name "sulphur of ivy" (a corruption of sulfur vivum) and used on hops.
Six days after the attacks, President Bush made a public appearance at Washington, D.C.'s largest Islamic Center where he acknowledged the "incredibly valuable contribution" of American Muslims and called for them "to be treated with respect." Numerous incidents of harassment and hate crimes against Muslims and South Asians were reported in the days following the attacks. Sikhs were also targeted due to their use of turbans, which are stereotypically associated with Muslims. There were reports of attacks on mosques and other religious buildings (including the firebombing of a Hindu temple), and assaults on individuals, including one murder: Balbir Singh Sodhi, a Sikh mistaken for a Muslim, who was fatally shot on September 15, 2001, in Mesa, Arizona. Two dozen members of Osama bin Laden's family were urgently evacuated out of the country on a private charter plane under FBI supervision three days after the attacks. According to an academic study, people perceived to be Middle Eastern were as likely to be victims of hate crimes as followers of Islam during this time. The study also found a similar increase in hate crimes against people who may have been perceived as Muslims, Arabs, and others thought to be of Middle Eastern origin. A report by the South Asian American advocacy group South Asian Americans Leading Together documented media coverage of 645 bias incidents against Americans of South Asian or Middle Eastern descent between September 11 and 17, 2001. Crimes such as vandalism, arson, assault, shootings, harassment, and threats in numerous places were documented.
Sources: en.wikipedia.org
Each freeze-thaw cycle can degrade a fraction of the peptide and promote aggregation. Dividing a stock solution into single-use volumes removes repeated cycling as a variable. It also limits the time a thawed solution spends at room temperature.
A high main-peak percentage says little about identity, counter-ion content, or residual solvents. It also does not distinguish an isomer or a closely eluting analog. Mass confirmation and the accompanying documentation cover those gaps.
Salt form changes mass, solubility, and hygroscopicity, and acetate and trifluoroacetate salts behave differently in solution. Storage guidance still centers on -20 °C for powder and lower temperatures for solutions. The certificate should state which salt is present.
Semax is a synthetic seven-amino-acid peptide derived from a fragment of corticotropin. It is used in Russia as a nasal preparation, while elsewhere it is studied as a research compound. It is not approved as a medicine in most countries.