The short version of N-acetyl Semax fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-03-30 and is reviewed periodically as new material appears.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It corresponds to the ACTH(4-7) fragment extended at the C-terminus by a Pro-Gly-Pro tripeptide, an addition intended to slow enzymatic breakdown. The molecular formula is C37H51N9O10S and the molecular mass is approximately 814 daltons. In the literature it is often described as an ACTH(4-10) analog, although that label reflects a naming convention as much as a precise structural relationship. The compound was developed in Russia and remains most closely associated with that research tradition.
Laboratory descriptions of the material are consistent across suppliers. It appears as a white to off-white lyophilized powder that dissolves readily in water and in polar organic solvents such as dimethyl sulfoxide. Aqueous solutions are clear and colorless at low concentrations. Because the peptide contains methionine, oxidation at the sulfur atom is a recognized degradation pathway, and handling notes usually call for protected, desiccated storage. Reported purity for research-grade lots is generally above 95 percent as measured by reversed-phase high-performance liquid chromatography.
The compound is registered in Russia as a pharmaceutical product, most commonly formulated as a nasal solution, and has been used in that setting since the 1990s. Outside that jurisdiction it is generally handled as a research chemical rather than an approved medicine. Regulatory status therefore differs sharply between countries, and material sold internationally may not correspond to the Russian pharmaceutical formulation. Documentation with commercial samples is typically limited to a certificate of analysis covering purity and identity, not clinical status or local legal classification.
Identity and purity are commonly assessed by reversed-phase high-performance liquid chromatography, with ultraviolet detection near 214 nanometers for the peptide backbone. Mass spectrometry, either electrospray or matrix-assisted laser desorption, confirms molecular mass and detects truncation or modification products. Amino acid analysis can verify composition. Because the sequence contains no strongly absorbing aromatic residue apart from phenylalanine, detection wavelengths are chosen carefully. Purity values above 95 percent are typical for research-grade material.
Quality documentation for research-grade peptide usually includes a certificate of analysis stating purity, identity, and residual counterion content. Batch-to-batch variation in purity and salt form is a recognized issue, and comparisons across suppliers require attention to the exact counterion, for example acetate versus trifluoroacetate. Sequence verification by tandem mass spectrometry provides stronger evidence than a single mass measurement. For any study reporting biological results, the analytical method and the measured purity should be stated explicitly. Independent verification of supplier claims is considered good practice.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Contains one methionine sulfur atom |
| Molecular mass | Approximately 814 Da | Consistent with a seven-residue peptide |
| Appearance | White to off-white powder | Typical lyophilized form |
| Solubility | Freely soluble in water | Also soluble in dimethyl sulfoxide |
| Typical storage | -20 °C, desiccated | Limits methionine oxidation |
Clinical reports describe use in ischaemic stroke, transient ischaemic attack, optic nerve conditions, and cognitive complaints, but most of these studies are small and were conducted in a single region. Systematic reviews have generally described the evidence base as limited in size and variable in methodological quality. Randomised controlled data suitable for international regulatory assessment are scarce. As a result, major treatment guidelines outside Russia do not include the peptide, and interest in it remains largely research-driven rather than routine clinical.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It is described in the literature as an analogue of the ACTH(4–10) fragment, a short N-terminal portion of adrenocorticotropic hormone that retains some neurotropic activity without the full hormonal effects of the parent peptide. The molecule carries a methionine residue at the N-terminus and two proline residues near the C-terminus, features that shape both its interactions with receptor systems and its chemical stability. The free peptide corresponds to the formula C37H51N9O10S and a molecular mass near 813.9 Da.
The compound was developed in the 1980s at the Institute of Molecular Genetics in Moscow, where it emerged from research on short ACTH fragments and their effects on the central nervous system. Russian pharmaceutical listings describe it as a nootropic and neuroprotective agent, most often formulated as nasal drops. It is not a marketed medicine in the United States or the European Union, and no pharmacopoeial monograph covers it. Consequently, most published clinical experience with the substance originates from a small number of research centres, mainly in Russia and neighbouring countries.
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.
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.
AntWiki – Bringing Ants to the World Wilson, Andrew (1878). "Ant" . Encyclopædia Britannica. Vol. II (9th ed.). pp. 94–100. AntWeb from The California Academy of Sciences Ant Species Fact Sheets from the National Pest Management Association on Argentine, Carpenter, Pharaoh, Odorous, and other ant species Ant Genera of the World – distribution maps The super-nettles. A dermatologist's guide to ants-in-the-plants
However, the military tide began to turn swiftly in favor of Franz Joseph and the Austrian whitecoats. Almost immediately, Charles Albert was decisively beaten by Radetzky at Novara and forced to sue for peace, as well as to renounce his throne.
== Epidemiology == The current estimated global incidence annually is 20,000 to 50,000 people, though a large number of cases are believed to go unreported. Due to the limited habitats of ciguatoxin-producing microorganisms, ciguatera is common only in subtropical and tropical waters, particularly the Pacific and Caribbean, and usually is associated with fish caught in tropical reef waters. Exportation of reef fish, as well as tourism, often account for cases that develop in other regions. Ciguatoxin is found in over 400 species of reef fish. Avoiding consumption of all reef fish is the only sure way to avoid exposure. Imported fish served in restaurants may contain the toxin and produce illness which often goes unexplained by physicians unfamiliar with the symptoms of a tropical toxin. Ciguatoxin can also occur in farm-raised salmon. Furthermore, species substitution, labeling a reef fish as a non-reef fish at restaurants and retail, can complicate efforts by consumers to avoid ciguatera.
Genetic mutations causing EDMD affect proteins comprising the nuclear membrane.Possibly, in all EDMD subtypes, there is impaired protein importation into the nucleus. Another possibility is that in all subtypes, there is a loss of nuclear structural integrity.
Sources: en.wikipedia.org
Some 3.3 V vaping devices using low-resistance heating elements such as an ohm of 1.5, containing 36 mg/mL liquid nicotine can obtain blood nicotine levels after 10 puffs that may be higher than with traditional cigarettes. A 2015 study evaluated "a variety of factors that can influence nicotine yield and found that increasing power output from 3 to 7.5 W (an approximately 2.5-fold increase), by increasing the voltage from 3.3 to 5.2 V, led to an approximately 4- to 5-fold increase in nicotine yield." A 2015 study, using a model to approximate indoor air workplace exposure, anticipates greatly reduced exposure to nicotine from e-cigarettes than traditional cigarettes. A 2016 World Health Organization (WHO) report found "nicotine in SHA [second-hand aerosol] has been found between 10 and 115 times higher than in background air levels." A 2015 Public Health England (PHE) report concluded that e-cigarettes "release negligible levels of nicotine into ambient air". A 2016 Surgeon General of the United States report stated that the exposure to nicotine from e-cigarette vaping is not negligible and is higher than in non-smoking environments. Vaping generates more surrounding air levels of particulate matter and nicotine in indoor areas than background air levels. Extended indoor e-cigarette use in rooms that are not sufficiently ventilated could surpass occupational exposure limits to the inhaled metals. The e-cigarette vapor may also contain tiny amounts of toxicants, carcinogens, and heavy metals.
Camptocormia comes from two Greek words, meaning "to bend" (κάμπτω, kamptō) and "trunk" (κόρμος, kormos), and was coined by Alexandre-Achille Souques and B. Rosanoff-Saloff. These two men also created the definition of the disease that is widely accepted today. When the disorder was first clinically studied around the time of First World War, it was believed to be a psychogenic conversion disorder that resulted from the severe trauma of war. Souques and others treated patients with psychological therapy and early versions of electrotherapy. Samuel A. Sandler used a similar approach to treat soldiers during the Second World War. The view of BSS as a conversion disorder led to a lack of awareness about the conditions and few diagnoses by physicians. As time progressed and advances were made in knowledge of neuroscience and physiology, biological mechanisms behind the irregular bending were identified. The current medically preferred term for the condition is bent spine syndrome, because of the psychological origin associated with camptocormia.
1993/2828) Finance Act 1993, section 211, (Appointed Day) Order 1993 (S.I. 1993/2831) A61 Trunk Road (Sheffield to Westwood Roundabout) (Detrunking) Order 1993 (S.I. 1993/2832) Building Societies (Aggregation) Rules 1993 (S.I. 1993/2833) Mid Glamorgan Ambulance National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2834) Derwen National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2835) North Wales Ambulance National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2836) Rhondda Health Care National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2837) Velindre National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2838) Gwynedd Community Health National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2839) Nevill Hall and District National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2840) Gwynedd Hospitals National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2841) Finance Act 1993, Chapter II, (Appointed Day) Order 1993 (S.I. 1993/2842) Payments to Redundant Churches Fund Order 1993 (S.I. 1993/2846) Ordination of Women (Financial Provisions) (Appeals) Rules 1993 (S.I. 1993/2847) East Anglian Ambulance National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2848) Norfolk Ambulance National Health Service Trust Dissolution Order 1993 (S.I. 1993/2849) Combined Probation Areas (Cumbria) Order 1993 (S.I. 1993/2852) Combined Probation Areas (Greater Manchester) Order 1993 (S.I. 1993/2853) Employment Appeal Tribunal Rules 1993 (S.I.
Vitamin A deficiency-caused night blindness is a reversible difficulty for the eyes to adjust to dim light. It is common in young children who have a diet inadequate in retinol and β-carotene. A process called dark adaptation typically causes an increase in photopigment amounts in response to low levels of illumination. This increases light sensitivity by up to 100,000 times compared to normal daylight conditions. Significant improvement in night vision takes place within ten minutes, but the process can take up to two hours to reach maximal effect. People expecting to work in a dark environment wore red-tinted goggles or were in a red light environment to not reverse the adaptation because red light does not deplete rhodopsin versus what occurs with yellow or green light.
In contrast, the French financial system was inadequate and Napoleon's forces had to rely in part on requisitions from conquered lands. From London in 1813 to 1815, Nathan Mayer Rothschild was crucial in almost single-handedly financing the British war effort, organising the shipment of bullion to the Duke of Wellington's armies across Europe, as well as arranging the payment of British financial subsidies to their continental allies.
Sources: en.wikipedia.org
In humans, evidence of a frameshift mutation in the bHLH domain of HAND1 has been correlated with hypoplastic left heart syndrome (a serious form of congenital heart disease where the left side of the heart is severely underdeveloped), aiding in the implication that HAND1 expression is a factor to patients with the disease. However, a lack of HAND1 in the distal regions of the Neural Crest has no effect on cranial feature formation. Mutation of HAND1 has been shown to hinder the effect of GATA4, another vital cardiac transcription factor, and is associated with congenital heart disease. The lack of HAND1 detection in the developing embryo leads to many of the structural defects that causes heart disease and facial deformities while the dosage of HAND1 relates to the severity of these maladies.
In the fields of medicine, biotechnology, and pharmacology, drug discovery is the process by which new candidate medications are discovered. Historically, drugs were discovered by identifying the active ingredient from traditional remedies or by serendipitous discovery, as with penicillin. More recently, chemical libraries of synthetic small molecules, natural products, or extracts were screened in intact cells or whole organisms to identify substances that had a desirable therapeutic effect in a process known as classical pharmacology. After sequencing of the human genome allowed rapid cloning and synthesis of large quantities of purified proteins, it has become common practice to use high-throughput screening of large compound libraries against isolated biological targets which are hypothesized to be disease-modifying in a process known as reverse pharmacology. Hits from these screens are then tested in cells and then in animals for efficacy. Modern drug discovery involves the identification of screening hits, medicinal chemistry, and optimization of those hits to increase the affinity, selectivity (to reduce the potential of side effects), efficacy and potency, metabolic stability (to increase the half-life), and oral bioavailability. Once a compound that fulfills all of these requirements has been identified, the process of drug development can continue. If successful, clinical trials are developed.
into the general solution produces orbits that escape to infinity (while still satisfying the equation of motion). Substituting the definitions for the axial and cyclotron frequencies, one might also write this condition as
=== Pharmacodynamics === Dihydroergotamine's antimigraine activity is due to its action as an agonist at the serotonin 5-HT1B, 5-HT1D, and 5-HT1F receptors. It also interacts with other serotonin, adrenergic, and dopamine receptors. Dihydroergotamine is an agonist of the serotonin 5-HT2B receptor and has been associated with cardiac valvulopathy. In spite of acting as an agonist of the serotonin 5-HT2A receptor, dihydroergotamine has been described as non-hallucinogenic. This is also the case with certain other ergoline derivatives, such as bromocriptine and pergolide.
27 October – Former Health Secretary Alex Neil calls for an urgent review of the use of WhatsApp by government following revelations that National Clinical Director Jason Leitch deleted messages on a daily basis during the pandemic; he also says that many government ministers did not understand the rules for using the app. 28 October – Ash Regan, who stood as a candidate in the 2023 SNP leadership election, defects to the Alba Party after becoming disillusioned with what she describes as the SNP's "wavering commitment" to Scottish independence. 29 October – First Minister Humza Yousaf says he has made contact with his in-laws trapped in Gaza for the first time since a communications blackout two days earlier. The Sunday Mail reports that WhatsApp messages relating to the COVID-19 pandemic sent by First Minister of Scotland, Nicola Sturgeon, were manually deleted from her phone. 30 October – First Minister Humza Yousaf says that allegations he deleted WhatsApp messages relating to the COVID-19 pandemic are "certainly not true". 31 October – Scotland's Deputy First Minister, Shona Robison, confirms that Scottish Government will hand 14,000 electronic messages relating to the pandemic to the UK COVID-19 Inquiry.
Sources: en.wikipedia.org
It is registered as a pharmaceutical product in Russia, where it is typically supplied as a nasal solution. In most other countries it is not an approved drug and is traded as a research chemical instead. Approval status depends entirely on the jurisdiction involved.
Most published work uses intranasal administration, matching the route of the registered Russian formulation. Some animal experiments use intravenous or intraperitoneal injection. The route matters because the intact peptide is cleared rapidly from blood, so exposure differs between methods.
A purity value describes the share of the powder accounted for by the target peptide, usually by high-performance liquid chromatography. It does not confirm that the sequence is correct, which requires mass spectrometry or amino acid analysis. Purity and identity are separate checks.
Solid peptide is best kept frozen at about minus 20 degrees Celsius in a sealed container with desiccant. It should be allowed to reach room temperature before opening to prevent condensation. Repeated warming and cooling of the same vial is discouraged.