heptapeptide raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-03-20 and is reviewed periodically as new material appears.
The parent fragment ACTH(4-10) carries the sequence Met-Glu-His-Phe-Arg-Trp-Gly. Semax replaces the arginine and tryptophan positions with a proline-glycine-proline tail, giving Met-Glu-His-Phe-Pro-Gly-Pro. That change removes residues associated with adrenal stimulation, so the peptide does not drive cortisol release the way full ACTH does. This distinction shapes how the compound is grouped in the literature, where it sits with neuropeptides and peptide neuromodulators rather than with corticosteroids.
Regulatory status varies sharply by country. Semax is registered for medical use in Russia, where it appears in formularies as a nasal solution, and it also holds registration in a small number of neighbouring states. It has no approval from the United States Food and Drug Administration or the European Medicines Agency, and it is not a scheduled controlled substance in most jurisdictions. Elsewhere it circulates mainly as laboratory material, so purity documentation comes from suppliers rather than from a national pharmacopoeia.
Pharmacological accounts link semax to melanocortin signalling and to modulation of neurotrophic factor expression, particularly brain-derived neurotrophic factor and nerve growth factor. Much of this evidence comes from rodent studies using intranasal delivery, a route chosen because it allows peptides to reach the central nervous system with limited systemic exposure. Whether the same mechanisms operate in humans at comparable magnitude remains an open question. The precise receptor or receptors responsible for the reported behavioural and neuroprotective effects have not been conclusively identified.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Analogue of the ACTH(4-10) fragment |
| Amino acid sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Single-letter form MEHFPGP |
| Molecular formula | C37H51N9O10S | Free peptide, nominal mass near 814 Da |
| First registration | 1994, Russia | Nasal formulation for neurological indications |
| Typical purity grade | 95% or higher by HPLC | Research material; higher grades used as reference standards |
The compound was developed during the 1980s at the Institute of Molecular Genetics in Moscow as part of research on fragments of adrenocorticotropic hormone. Early work examined short ACTH-derived sequences that retained neurotrophic effects while lacking the endocrine activity of the full hormone. Semax entered clinical use in Russia during the 1990s, where it received registration for several neurological indications. Outside that region it remained primarily a laboratory research material rather than an approved therapeutic. English-language literature on it grew more slowly and frequently cited the original Russian studies.
Terminology around the compound varies by source. It appears in catalogues and papers as Semax, as the heptapeptide ACTH(4-7)-Pro-Gly-Pro, and under various alphanumeric laboratory codes used by individual suppliers. These names refer to the same sequence but may imply different salt forms, purity grades, or counter-ions. Peptide databases usually list the free base mass, while product descriptions sometimes report acetate or trifluoroacetate salts with a different formula weight. Because naming conventions for research peptides are not standardised across vendors, checking the declared sequence and measured mass is more reliable than relying on a trade name alone.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. It was developed as a fragment analog of adrenocorticotropic hormone, modeled specifically on the ACTH(4-10) region. The first four residues reproduce that fragment, while a Pro-Gly-Pro tripeptide is appended at the C-terminus. Work on the compound originated in Russia, where it entered clinical use as an intranasal preparation. Its sequence places it among short regulatory peptides studied for effects on the central nervous system rather than on the adrenal axis.
The C-terminal Pro-Gly-Pro extension is not incidental. Proline-rich tails are known to resist several common peptidases, and the published literature attributes the longer half-life of Semax, relative to unmodified ACTH fragments, to this feature. The modification also removes the melanocyte-stimulating and corticosteroidogenic activity that characterizes longer ACTH-derived sequences. Because the molecule is small and hydrophilic, it is typically formulated as an aqueous solution for intranasal or parenteral delivery. Acetylation or amidation at the termini appears in closely related research peptides and shifts the mass by a fixed increment.
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.
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.
== Use == Once extracted, oil is refined and separated, most easily by distillation, into numerous products for direct use or use in manufacturing, such as gasoline (petrol), diesel and kerosene to asphalt and chemical reagents (ethylene, propylene, butene, acrylic acid, para-xylene) used to make plastics, pesticides and pharmaceuticals. In terms of volume, most petroleum is converted into fuels for combustion engines. In terms of value, petroleum underpins the petrochemical industry, which includes many high value products such as pharmaceuticals and plastics. By volume, 84% of hydrocarbons present in petroleum are converted into fuels.
Dezocine, sold under the brand name Dalgan, is an atypical opioid analgesic which is used in the treatment of pain. It is used by intravenous infusion and intramuscular injection. Dezocine is an opioid receptor modulator, acting as a partial agonist of the μ- and κ-opioid receptors. It is a biased agonist of the μ-opioid receptor. The drug has a similar profile of effects to related opioids acting at the μ-opioid receptor, including analgesia and euphoria. Unlike other opioids acting at the κ-opioid receptor however, dezocine does not produce side effects such as dysphoria or hallucinations at any therapeutically used dose. Dezocine was first synthesized in 1970. It was introduced for medical use in the United States in 1986 but was not marketed in other countries. Dezocine was discontinued in the United States in 2011 with no official reason given. However, it has become one of the most widely used analgesics in China. In light of the opioid epidemic, dezocine has seen a resurgence in use and interest.
AlphaFold 1 (2018) was built on work developed by various teams in the 2010s, work that looked at the large databases of related protein sequences now available from many different organisms (most without known 3D structures), to try to find changes at different residues (peptides) that appeared to be correlated, even though the residues were not consecutive in the main chain. Such correlations suggest that the residues may be close to each other physically, even though not close in the sequence, allowing a contact map to be estimated. Building on recent work prior to 2018, AlphaFold 1 extended this by estimating a probability distribution for the distances between residues, effectively transforming the contact map into a distance map. It also used more advanced learning methods than previously to develop the inference. The code was not made publicly available, except to run on sequences of proteins in the 2018 CASP competition.
The amplitude of SHOC2-mediated ERK1/2 signals has been proposed to be regulated by differential regulation of RAF activation at the plasma membrane and internalized endosome compartment as well an alternative model proposing post-translational modifications. SHOC2 ubiquitination mediated by HUWE1 is triggered by growth factor activation of the ERK1/2 pathway and is a prerequisite for the subsequent ubiquitination of the RAF-1 kinase associated with SHOC2. However, the current data has yet to address how these ubiquitin modifications regulate the SHOC2 holophosphatase function to reduce the amplitude of RAF-ERK1/2 signals. It has been shown that activity that results in lipidation (specifically Myristoylation) of SHOC2 can cause Noonan syndrome. SHOC2 has been shown to interact with the catalytic phosphatase subunit PP1C and MRAS as well as canonical RAS isoforms (H/K/NRAS). The ternary complex SHOC2-RAS-PP1C functions to dephosphorylate an inhibitory phosphorylation site ('S259') on RAF family proteins to enable MAPK signaling.
== Nucleosynthesis == Americium-241 has been produced in small quantities in nuclear reactors for decades, and many kilograms of 241Am have been accumulated by now. Since it was first offered for sale in 1962, after a long period of price stability due to its complex production process, its price, about US$25,000 per gram of 241Am, including packaging/dispensing fees, has risen significantly since then, especially in recent years. Americium-241 is synthesized by three neutron captures on uranium-238 present in reactors:
Sources: en.wikipedia.org
Tens of genes and CNVs have been definitively identified based on the observation of recurrent mutations in different individuals, and suggestive evidence has been found for over 100 others. The Simons Foundation Autism Research Initiative (SFARI) details the evidence for each genetic locus associated with autism. These early gene and CNV findings have shown that the cognitive and behavioral features associated with each of the underlying mutations is variable. Each mutation is itself associated with a variety of clinical diagnoses, and can also be found in a small percentage of individuals with no clinical diagnosis. Thus the genetic disorders that comprise autism are not autism-specific. The mutations themselves are characterized by considerable variability in clinical outcome and typically only a subset of mutation carriers meet criteria for autism. This variable expressivity results in different individuals with the same mutation varying considerably in the severity of their observed particular trait. The conclusion of these recent studies of de novo mutation is that the spectrum of autism is breaking up into quanta of individual disorders defined by genetics. One gene that has been linked to autism is SHANK2. Mutations in this gene act in a dominant fashion and appear to cause hyperconnectivity between the neurons. A study conducted on 42,607 autism cases has identified 60 new genes, five of which had a more moderate impact on autistic symptoms. The related gene variants were often inherited from the participant's parents.
This victory contributed to a general Allied breakthrough in the area, and by 19 April, the 6th Division's armour was moving towards Lombardy and Venetia as part of the Fifth Army's vanguard. American and Polish troops entered Bologna on 21 April. The South Africans and Rhodesians advanced north-west towards the Panaro river. The Special Service Battalion's Rhodesian squadron, moving forward alongside the Cape Town Highlanders, and the Rhodesians of Prince Alfred's Guard took part in numerous engagements with the retreating German rearguard, and suffered several fatalities. The 6th Division crossed the Po near Ostiglia on 25 April and, after resupplying for a week, began a speedy advance towards Venice, aiming to cut off the retreat of elements of the German Fourteenth Army. The South Africans and Rhodesians advanced through Nogara and Cerea, crossed the Adige early on 29 April, and then made for Treviso, 19 kilometres (12 mi) north of Venice. The retreating German forces were by this time in such disarray that, during its advance from the Po, the 11th South African Armoured Brigade took prisoners from eight German divisions. On 30 April, the 6th Division joined up with British and American forces south of Treviso, and cut off the Germans' last escape route from Italy. The German forces in Italy surrendered unconditionally on 2 May 1945, while the 6th Division was moving north-west; at the time of the announcement it was near Milan.
To diagnose LMS, a physical exam may be performed by one's physician, imaging tests such as MRI, CT, and PET scans can be performed, or tissue biopsies can also be completed where the histopathology of the removed tissue sample is examined.
Distillation of chemicals such as in petroleum refining is done in towers or columns with perforated trays. Vapor from the low boiling fractions bubbles upward through the holes in the trays in contact with the down flowing high boiling fractions. The concentration of low boiling fraction increases in each tray up the tower as it is "stripped". The low boiling fraction is drawn off the top of the tower and the high boiling fraction drawn from the bottom. The process in the trays is a combination of heat transfer and mass transfer. Heat is supplied at the bottom, known as a "reboiler" and cooling is done with a condenser at the top.
Sources: en.wikipedia.org
Registered medical products are most often 0.1% nasal drops. Research suppliers ship lyophilized powder, usually in milligram quantities, which is dissolved before use. The active peptide is the same in both cases; presentation and excipients differ.
No. The peptide is synthetic, although it is modelled on a fragment of a naturally occurring hormone. ACTH(4-10) is generated when ACTH is cleaved, but the Pro-Gly-Pro extension is not a known endogenous sequence. It is therefore a designed analogue rather than a natural metabolite.
The label reflects reported effects on attention, memory and recovery after neurological injury in regional clinical reports. Those reports are mostly small and have not been widely replicated outside the region. The classification is descriptive and does not imply a single defined mechanism.
It is described as a synthetic analogue of the ACTH(4–10) fragment, a short segment of adrenocorticotropic hormone. Its sequence differs from that fragment and includes two proline residues, which influence stability and behaviour in solution.