If you have been reading about lyophilised powder 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 2026-02-20. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Semax is a synthetic peptide created in the Soviet Union during the early 1980s by researchers working in Moscow. It was built from the short adrenocorticotropic hormone fragment known as ACTH(4-10), and the chain was then extended with three additional amino acids. The resulting molecule was named semax and entered clinical use in Russia in 1994. It is generally described as a nootropic and neuroprotective agent rather than as a hormone analogue.
Purity assessment relies mainly on reversed-phase high-performance liquid chromatography, which separates the target heptapeptide from truncated sequences, deletion analogues, and oxidised forms. Mass spectrometry, usually coupled to liquid chromatography, confirms identity through the expected molecular ion and reveals modifications such as methionine sulfoxide formation. Amino acid analysis can verify composition, and tandem mass spectrometry supports sequence confirmation. Ultraviolet detection near 254 to 280 nanometres is convenient because the phenylalanine and histidine residues absorb in that region. Nuclear magnetic resonance is rarely used for routine release testing.
Common degradation pathways include oxidation of the methionine side chain, hydrolysis of the peptide backbone, and aggregation under unfavourable pH or concentration. Stability studies typically monitor the main peak by chromatography and report total related substances as a percentage. Because no official monograph exists, acceptance criteria vary between laboratories, and reported purity values are not directly comparable across suppliers. Analysts therefore document the method, column, and detection wavelength alongside each result, and open questions remain about how much biological activity the oxidised forms retain.
| 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 |
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.
Lyophilised powder is normally kept at -20 °C in a desiccated container, with some suppliers recommending -80 °C for long-term archival storage. Repeated freeze-thaw cycles are the most common cause of avoidable loss, so aliquoting before freezing reduces variability between working sessions. Dissolved peptide is far less stable than the dry solid and is usually prepared fresh or held briefly at 4 °C. Aqueous solutions support both hydrolysis of the backbone and oxidation of the N-terminal methionine, and these two routes dominate degradation under ordinary laboratory conditions.
Identity and purity are confirmed with reversed-phase high-performance liquid chromatography, typically monitored at 214 nanometres where the peptide bond absorbs. Mass spectrometry, either electrospray or MALDI-TOF, verifies molecular mass against the theoretical value and detects truncation or adduct formation. Amino acid analysis and peptide mapping provide additional confirmation when required. The most frequently reported impurities are deletion sequences from incomplete coupling, methionine sulfoxide from oxidation, and dimeric species formed through non-covalent aggregation. Impurity profiles depend strongly on the synthesis and purification route chosen by the producer.
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 with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its design combines the ACTH(4-7) core fragment with a C-terminal Pro-Gly-Pro extension, a modification intended to improve stability and prolong activity. The molecule is hydrophilic, carries no lipid chains or glycosylation, and has a theoretical mass just over 810 daltons in its free form. All seven residues are proteinogenic amino acids, so no non-natural building blocks appear in the backbone. A free N-terminal methionine and C-terminal proline define the unmodified parent peptide.
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 normally supplied as a lyophilized powder, and that form is the most stable. Suppliers commonly recommend storage at -20 °C in a desiccated container protected from light, with short-term handling at room temperature limited to weighing and transfer. Powder that has absorbed moisture degrades faster, so vials should be warmed to ambient temperature before opening to prevent condensation on the contents. Hygroscopic behavior is typical of short hydrophilic peptides, and humidity control matters more than temperature alone for long-term retention.
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.
Along with the international protection, Mexico has also sought similar protection for tequila in other important countries and regions through a number of bilateral and multilateral agreements. Pursuant to Annex 313 of the North American Free Trade Agreement (NAFTA), Canada and the United States recognize tequila and mezcal as products originating from Mexico and, consequently, do not permit the sale of any product as tequila and/or mezcal unless they have been lawfully prepared in Mexico. The Mexican government enforces the tequila intellectual property through the Mexican Institute of Industrial Property (IMPI). The use of the name tequila is authorized and administered only by IMPI. IMPI may prohibit any unauthorized use of the name that may create confusion for the consumers, or constitute an act of unfair competition. Despite protection under the Lisbon Agreement and NAFTA, tequila still faced competition from some pseudo tequilas. During the mid-1990s, as much as 3.5 million liters of these liquors were sold annually in Europe. The European liquors were produced from sugars of agave-like plants and were illegally labeled as tequila. Following the NAFTA precedent, Mexico entered into a bilateral agreement with the European Union concerning the mutual recognition and protection of AO in the spirits sector. Under this agreement the EU recognizes tequila and mezcal as "denominations of origin", although enforcement has still been quite lax in Europe.
==== 2001–2006: Second double, Invincibles, and leaving Highbury ==== The cup defeat prompted Wenger to make changes to his squad. He signed young England internationals Richard Wright and Francis Jeffers, midfielder Giovanni van Bronckhorst from Rangers as a partner for Vieira, and convinced defender Sol Campbell to join from local rivals Tottenham Hotspur on a free transfer. Campbell's arrival strengthened a defence which was going through a transition phase from 1999 and 2001; Steve Bould and Nigel Winterburn moved on in this period, club graduate Ashley Cole displaced Sylvinho as Wenger's first choice left back, while Lauren acted as Lee Dixon's understudy. Midfielders Freddie Ljungberg and Robert Pires – brought in during preceding transfer windows, had now established themselves into the first team. The 2001–02 season brought much success as Wenger led Arsenal to the double once more. The crowning moment was the win against Manchester United at Old Trafford in the penultimate game of the season. Sylvain Wiltord scored the winning goal to secure the club's 12th league championship and third double; four days earlier, Arsenal beat Chelsea 2–0 in the 2002 FA Cup Final. The team scored in every single league fixture and were unbeaten away from home that season.
Kingdom of Serbs, Croats and Slovenes (1918–1929) Kingdom of Yugoslavia (1929–1945) Democratic Federal Yugoslavia (1945) Federal People's Republic of Yugoslavia (1945–1963) Socialist Federal Republic of Yugoslavia (1963–1992) It enjoyed success in international competition, reaching the semi-finals at the 1930 and 1962 FIFA World Cups. In 1992, during the Yugoslav wars, the team was suspended from international competition as part of the United Nations sanctions on Yugoslavia.
Geological Survey, and Kathleen Crane of Scripps Institution of Oceanography. This team published their observations of the vents, organisms, and the composition of the vent fluids in the journal Science. In 1979, a team of biologists led by J. Frederick Grassle, at the time at WHOI, returned to the same location to investigate the biological communities discovered two year earlier. High temperature hydrothermal vents, the "black smokers", were discovered in spring 1979 by a team from the Scripps Institution of Oceanography using the submersible Alvin. The RISE expedition explored the East Pacific Rise at 21° N with the goals of testing geophysical mapping of the sea floor with the Alvin and finding another hydrothermal field beyond the Galápagos Rift vents. The expedition was led by Fred Spiess and Ken Macdonald and included participants from the U.S., Mexico and France. The dive region was selected based on the discovery of sea floor mounds of sulfide minerals by the French CYAMEX expedition in 1978. Prior to dive operations, expedition member Robert Ballard located near-bottom water temperature anomalies using a deeply towed instrument package. The first dive was targeted at one of those anomalies. On Easter Sunday April 15, 1979 during a dive of Alvin to 2,600 meters, Roger Larson and Bruce Luyendyk found a hydrothermal vent field with a biological community similar to the Galápagos vents. On a subsequent dive on April 21, William Normark and Thierry Juteau discovered the high temperature vents emitting black mineral particle jets from chimneys; the black smokers.
=== Activation by protease and metalloprotease === Plasmin and a member of matrix metalloproteinases (MMP) play a key role in promoting tumor invasion and tissue remodeling by inducing proteolysis of several ECM components. The TGF-β activation process involves the release of the LLC from the matrix, followed by further proteolysis of the LAP to release TGF-β to its receptors. MMP-9 and MMP-2 are known to cleave latent TGF-β. The LAP complex contains a protease-sensitive hinge region which can be the potential target for this liberation of TGF-β. Despite the fact that MMPs have been proven to play a key role in activating TGF-β, mice with mutations in MMP-9 and MMP-2 genes can still activate TGF-β and do not show any TGF-β deficiency phenotypes, this may reflect redundancy among the activating enzymes suggesting that other unknown proteases might be involved.
Sources: en.wikipedia.org
These antibodies circulate in blood plasma and lymph, bind to pathogens expressing the antigen and mark them for destruction by complement activation or for uptake and destruction by phagocytes. Antibodies can also neutralize challenges directly, by binding to bacterial toxins or by interfering with the receptors that viruses and bacteria use to infect cells.
Ultrapure water (UPW), high-purity water or highly purified water (HPW) is water that has been purified to stringent specifications. Ultrapure water is a term commonly used in manufacturing to emphasize the fact that the water is treated to the highest levels of purity for all contaminant types, including organic and inorganic compounds, dissolved and particulate matter, and dissolved gases, as well as volatile and non-volatile compounds, reactive and inert compounds, and hydrophilic and hydrophobic compounds. In contrast to deionized (DI) water, UPW has organic particles and dissolved gases removed in addition to ions. Ultrapure water is typically prepared in three broadly-defined stages: pretreatment, primary treatment, and polishing/transport. While various industries use the term "ultrapure water", the exact definitions differ among industries. Standards for ultrapure water are defined by various groups for the power industry, semiconductor industry, and pharmaceutical industry. Water purity requirements of the semiconductor industry are generally the most stringent to prevent circuit faults at the nanometer scale.
=== Signalling of fetal maturation and parturition === As pregnancy advances to term, the fetal membranes undergo weakening. The amnion is vital in the synthesis of prostaglandins which reach the myometrium and create and initiate parturition. The chorion expresses chemicals that balance synthesis and metabolism of these prostaglandins to ensure that the myometrium is not activated pre-term. Prostaglandin E2 is thought to be synthesized by cells in the amnion and is essential in dilation of the cervix at the initiation of parturition. Glucocorticoids have been implicated in fetal maturation, regulation of immune response and many other pregnancy associated changes. As well as its function in parturition, Prostaglandin E2 is vital for fetal lung maturation. Additionally, there is an abundance of 11β-hydroxysteroid dehydrogenase 1 expressed in the foetal membranes. This enzyme converts biologically inactive cortisone into active cortisol, another chemical vital for fetal maturation and labour initiation.
=== Gas chromatography-mass spectrometry === Gas chromatography-mass spectrometry (GC-MS) is a widely used analytical technique for the detection of volatile compounds. Ionization techniques most frequently used in forensic toxicology include electron ionization (EI) or chemical ionization (CI), with EI being preferred in forensic analysis due to its detailed mass spectra and its large library of spectra. However, chemical ionization can provide greater sensitivity for certain compounds that have high electron affinity functional groups.
Sources: en.wikipedia.org
== Interactions == GLUT4 has been shown to interact with death-associated protein 6, also known as Daxx. Daxx, which is used to regulate apoptosis, has been shown to associate with GLUT4 in the cytoplasm. UBX-domains, such as the one found in GLUT4, have been shown to associate with apoptotic signaling. So this interaction aids in the translocation of Daxx within the cell. In addition, recent reports demonstrated the presence of GLUT4 gene in central nervous system such as the hippocampus. Moreover, impairment in insulin-stimulated trafficking of GLUT4 in the hippocampus result in decreased metabolic activities and plasticity of hippocampal neurons, which leads to depressive like behaviour and cognitive dysfunction.
==== Intracellular trafficking ==== Actin-myosin pairs can also participate in the trafficking of various membrane vesicles and organelles within the cell. Myosin V is activated by binding to various cargo receptors on organelles, and then moves along an actin filament towards the (+) end, pulling its cargo along with it. These nonconventional myosins use ATP hydrolysis to transport cargo, such as vesicles and organelles, in a directed fashion much faster than diffusion. Myosin V walks towards the barbed end of actin filaments, while myosin VI walks toward the pointed end. Most actin filaments are arranged with the barbed end toward the cellular membrane and the pointed end toward the cellular interior. This arrangement allows myosin V to be an effective motor for the export of cargos, and myosin VI to be an effective motor for import.
One possible advantage of the therapeutic approach of blocking viral entry (as opposed to the currently dominant approach of viral enzyme inhibition) is that it may prove more difficult for the virus to develop resistance to this therapy than for the virus to mutate or evolve its enzymatic protocols.
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.
Dry powder is usually kept at about -20 degrees Celsius for long-term storage and at 2 to 8 degrees Celsius for short working periods. Containers should stay sealed and protected from light and moisture to limit degradation.