If you have been reading about semax and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-01-18. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It was derived from the ACTH(4-10) fragment, a short segment of adrenocorticotropic hormone that lacks the hormonal activity associated with the full-length peptide. Researchers at the Institute of Molecular Genetics in Moscow developed the compound during the 1980s. It has been registered as a pharmaceutical product in Russia and several neighbouring countries, where it is supplied as a nasal solution, and it is also sold internationally as a research chemical.
The proposed mechanism centres on neurotrophic signalling rather than direct receptor activation. Semax is reported to increase expression of brain-derived neurotrophic factor and nerve growth factor in several brain regions, and to shift the balance between excitatory and inhibitory neurotransmitter systems. Interaction with melanocortin receptors has been suggested because of the parent ACTH fragment. Many of these findings come from rodent studies, and the extent to which they translate to human physiology remains an open question.
| 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 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.
Semax binds to melanocortin receptors and is thought to influence neuronal survival and plasticity rather than to act through the adrenal axis. Laboratory work has shown increased expression of brain-derived neurotrophic factor and nerve growth factor in treated tissue. Changes in c-Fos, a marker of neuronal activation, have also been reported. Because the peptide is rapidly degraded by peptidases, its effects are generally attributed to downstream signaling cascades rather than to sustained receptor occupancy.
研究兴趣主要集中在神经营养因子相关的路径上，包括脑源性神经营养因子与神经生长因子的表达变化。部分实验报告称在特定条件下观察到这些因子的水平上升，但具体信号通路和剂量依赖关系仍未完全厘清。多数公开数据来自细胞模型和动物实验，人体对照研究数量有限。因此，该化合物的作用机制在文献中属于活跃讨论，而非已经确立的定论。
Semax 是一种人工合成的七肽，氨基酸序列为 Met-Glu-His-Phe-Pro-Gly-Pro，单字母缩写记作 MEHFPGP。它被归类为促肾上腺皮质激素片段 ACTH(4-10) 的结构类似物，但并不天然存在于生物体内。母体片段 ACTH(4-10) 的序列为 Met-Glu-His-Phe-Arg-Trp-Gly，Semax 替换了中间两个残基，并在羧基端延长了 Pro-Gly-Pro 三肽。这种延长被普遍认为能提升分子对肽酶的耐受性。
该化合物于二十世纪八十年代在俄罗斯被开发，相关工作由俄罗斯科学院分子遗传学研究所的研究团队主导。开发目标并非复制 ACTH 的完整激素活性，而是寻找保留其神经作用方向、同时去除促肾上腺皮质激素释放效应的短肽片段。研究记录显示，这一方向促成了多个相关短肽的合成与筛选，而 Semax 是其中被研究最广泛的一个。当地文献常以 Семакс 这一名称指代它。
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.
Verification of a supplied batch generally combines a certificate of analysis with independent testing, because certificates are self-reported documents. A typical package includes a chromatographic trace, a mass spectrum, and a stated water or counter-ion content. Batch-to-batch consistency matters more than a single purity figure when results are compared across experiments. No single mandatory standard governs research-grade peptide release, so laboratories are expected to define their own acceptance criteria. Residual trifluoroacetate from purification is a frequently overlooked counter-ion.
where Ntotal is the constant number of particles throughout the decay process, which is equal to the initial number of A nuclides since this is the initial substance. If the number of non-decayed A nuclei is:
==== Usage in global industry ==== Direct oxidation of ethylene was patented by Lefort in 1931. This method was repeatedly modified for industrial use, and at least four major variations are known. They all use oxidation by oxygen or air and a silver-based catalyst, but differ in the technological details and hardware implementations. Union Carbide (currently a division of Dow Chemical Company) was the first company to develop the direct oxidation process. A similar production method was developed by Scientific Design Co., but it received wider use because of the licensing system – it accounts for 25% of the world's production and for 75% of world's licensed production of ethylene oxide. A proprietary variation of this method is used by Japan Catalytic Chemical Co., which adapted synthesis of both ethylene oxide and ethylene glycol in a single industrial complex. A different modification was developed Shell International Chemicals BV. Their method is rather flexible with regard to the specific requirements of specific industries; it is characterized by high selectivity with respect to the ethylene oxide product and long lifetime of the catalyst (3 years). It accounts for about 40% of global production. Older factories typically use air for oxidation whereas newer plants and processes, such as METEOR and Japan Catalytic, favor oxygen.
The geographical boundary of this unusual marriage pattern is now known as the Hajnal line; also worked on demography for United Nations, and for the Office of Population Research, Princeton University; was member of the International Statistical Institute and was elected FBA. Charlotte Haldane (27 April 1894 – 16 March 1969) was a British writer known as a feminist but also for anti-feminism in her 1927 book, Motherhood and its Enemies. In 1937 she worked as editor of the anti-fascist magazine Woman Today. and during the Spanish Civil War she took part in fund-raising activities on behalf of the International Brigades.In 1941 she went to Moscow to report on Soviet defense against the Nazis. Keith Kahn-Harris author, sociologist and music critic; honorary research fellow and senior lecturer at Birkbeck College and an associate fellow of the Institute for Jewish Policy Research and a lecturer at Leo Baeck College; has published academic and non-academic articles on Judaism, music scenes, heavy metal music, transgression, Israel, communities, dialogue, religion, ethnicity, political discourse, and denial; also writes for Medium, The Guardian, The Independent, Times of Israel, Haaretz, The Herald (Scotland), New Statesman, Times Higher Education (THE), The i Paper, openDemocracy; from 2001 to 2002 was "Jerusalem Fellow" at the Mandel School for Advanced Educational Leadership in Jerusalem.
Sources: en.wikipedia.org
Despite controls in place, the species comprising the mixed cultures can still initiate metabolic change preparation to preparation with the slightest change in co-culture conditions and alter product qualities such as sugar concentration, so adequate monitoring is necessary when running in a continuous mode or reusing a starter culture.
The Springboks had fulfilled all of their touring commitments through the Fifties and Sixties but the oppressive, claustrophobic political pressures overwhelmed them during the Seventies. They have not been able to play in Britain, Ireland, France or Australia since 1974, and their only major tour abroad in the last ten years to New Zealand in 1981, was full of controversy, and mass demonstrations. There is no doubt that giant steps have been taken to make Rugby totally integrated in South Africa in recent years, and their supporters feel that no sooner have they fulfilled the conditions required of them by world opinion than the goalposts are moved. Their opponents, who are against having any sporting links with a country which practises apartheid, accept that sport in South Africa has become increasingly integrated but claim it is impossible to have normal sport in an abnormal society.
small ubiquitin-like modifier (SUMO) Any of a family of small proteins, each approximately 100 amino acids, which are covalently conjugated to and removed from charged residues of other proteins in a form of post-translational modification known as SUMOylation, thereby functioning as a protein tag in a manner resembling ubiquitin.
== Signs and symptoms == Manifestations of hyperinsulinemic hypoglycemia vary by age and severity of the hypoglycemia. In general, most signs and symptoms can be attributed to (1) the effects on the brain of insufficient glucose (neuroglycopenia) or (2) to the adrenergic response of the autonomic nervous system to hypoglycemia. A few miscellaneous symptoms are harder to attribute to either of these causes. In most cases, all effects are reversed when normal glucose levels are restored. There are uncommon cases of more persistent harm, and rarely even death due to severe hypoglycemia of this type. One reason hypoglycemia due to excessive insulin can be more dangerous is that insulin lowers the available amounts of most alternate brain fuels, such as ketones. Brain damage of various types ranging from stroke-like focal effects to impaired memory and thinking can occur. Children who have prolonged or recurrent hyperinsulinemic hypoglycemia in infancy can suffer harm to their brains and may be developmentally delayed.
Sources: en.wikipedia.org
== Treatment == Symptomatic treatment usually involves analgesics for both cranial and spinal CSF leaks. Initial measures can include rest, caffeine intake (via coffee or intravenous infusion), and hydration. Corticosteroids may provide transient relief for some patients. An abdominal binder, which increases intracranial pressure by compressing the abdomen, can temporarily relieve symptoms for some people. Sometimes a CSF leak will heal on its own. Otherwise, symptoms may last months or even years.
=== In war === Illicit use of the drug is thought to be a major factor in the success of the Boko Haram terrorist organization. When used at higher doses, the drug "can produce similar effects to heroin." One former member said, "whenever we took tramadol, nothing mattered to us anymore except what we were sent to do because it made us very high and very bold, it was impossible to go on a mission without taking it." Tramadol is also used as a coping mechanism in the Gaza Strip. In the 2020's Anti-balaka militias in the Central African Republic were reported to be in control of the Tramadol trade, providing it to fighters, workers in illegal goldmines and organising the sale on local markets. Researchers report the drug is brought by Dubai based company Shalina from India and China to the Democratic Republic of the Congo, from where it is smuggled into the Central African Republic.
Barrett in 2017 suggested a radical revision of dinosaurian systematics. Phylogenetic analysis by Baron et al. recovered the Ornithischia as being closer to the Theropoda than the Sauropodomorpha, as opposed to the traditional union of theropods with sauropodomorphs. This would cause sauropods and kin to fall outside traditional dinosaurs, so they re-defined Dinosauria as the last common ancestor of Triceratops horridus, Passer domesticus and Diplodocus carnegii, and all of its descendants, to ensure that sauropods and kin remain included as dinosaurs. They also resurrected the clade Ornithoscelida to refer to the group containing Ornithischia and Theropoda.
Since the precise structure or peptide sequence of a molecule is deciphered through the set of fragment masses, the interpretation of mass spectra requires combined use of various techniques. Usually the first strategy for identifying an unknown compound is to compare its experimental mass spectrum against a library of mass spectra. If no matches result from the search, then manual interpretation or software assisted interpretation of mass spectra must be performed. Computer simulation of ionization and fragmentation processes occurring in mass spectrometer is the primary tool for assigning structure or peptide sequence to a molecule. An a priori structural information is fragmented in silico and the resulting pattern is compared with observed spectrum. Such simulation is often supported by a fragmentation library that contains published patterns of known decomposition reactions. Software taking advantage of this idea has been developed for both small molecules and proteins. Analysis of mass spectra can also be spectra with accurate mass. A mass-to-charge ratio value (m/z) with only integer precision can represent an immense number of theoretically possible ion structures; however, more precise mass figures significantly reduce the number of candidate molecular formulas. A computer algorithm called formula generator calculates all molecular formulas that theoretically fit a given mass with specified tolerance.
The Church of Saidet et Tallé in Deir el Qamar is one of the most significant historical and religious sites in Mount Lebanon. The original church was destroyed by the Saracens and later rebuilt during the reign of Fakhreddine I Maan (1518-1544). For centuries, this church has been revered by both Druze and Christians in Mount Lebanon, reflecting the close ties between the two communities. According to Pierre-Marie Martin, writing in 1870, the Druze venerated the church even more than the Maronites, often traveling long distances to pray to the Virgin Mary in their own way and "witnessing numerous miracles". Historian Glenn Bowman further highlights that in the early nineteenth century, Druze leaders would seek the Virgin Mary's favor at Saidet et Tallé before going into battle. They would touch the image of the Virgin Mary with their flags and place dust from under the altar in their turbans. The profound veneration of this church by the Druze led local Maronites to dub it the "Church of the Virgin of the Druze". Since the sixteenth century, prominent Druze feudal families have welcomed Protestant missionaries, as well as, Catholic missionaries like Franciscans, Jesuits, Carmelites, and Lazarites to the region, all of whom contributed to the spread of education and literacy. Several feudal Druze families also funded the construction of churches in their strongholds.
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 based on the ACTH(4-10) fragment, a seven-amino-acid segment of adrenocorticotropic hormone. The synthetic peptide retains the core sequence while removing regions associated with endocrine activity. This modification is intended to isolate effects on the nervous system.