A practical reference on Semax: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-12-29. Anything still debated is marked as such rather than presented as settled.
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.
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.
Published research has focused mainly on neurological and cognitive endpoints in animal models, with proposed mechanisms involving brain-derived neurotrophic factor and related signalling pathways. A substantial share of the human data originates from a limited number of research groups, and independent replication in other countries remains sparse. Regulatory status reflects that distribution: the peptide is registered as a medicine in Russia and appears in some neighbouring markets, while elsewhere it is handled as a research chemical without approved therapeutic labelling. Questions about dose-response relationships, long-term effects, and comparability across studies are still open.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic heptapeptide | Analog of an ACTH fragment |
| Amino acid length | Seven residues | Met-Glu-His-Phe-Pro-Gly-Pro |
| Origin | Moscow, 1980s | Institute of Molecular Genetics |
| Approved regions | Russia and some neighboring states | Not cleared in Western markets |
| Common trade names | Multiple national brands | Sold as a nasal formulation |
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.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its chain combines the first seven residues of corticotropin with a C-terminal proline-glycine-proline extension, a modification intended to slow enzymatic breakdown. The free peptide has a molecular mass near 813.9 daltons. It belongs to the class of ACTH-derived fragments studied for central nervous system activity rather than for adrenal steroid stimulation. This structural relationship to a natural hormone fragment is the usual starting point for describing the compound in the literature.
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.
The peptide is prone to several degradation pathways. Oxidation of the methionine residue produces a sulfoxide that elutes close to the parent peak in many chromatographic systems. Hydrolysis of peptide bonds and deamidation of susceptible residues in related sequences also reduce purity over time. Lyophilised material kept dry at minus twenty degrees Celsius and shielded from light is the most stable form commonly described in laboratory practice.
Material sold for laboratory use varies widely in stated purity and documentation. A certificate of analysis should list the analytical method, the column and detector used, and the observed purity value. Independent verification by an outside laboratory is the practical way to confirm identity when documentation is absent or internally inconsistent. Regulatory status differs by country, and a product legal in one jurisdiction may be unapproved or controlled in another.
== Analysis of cellular organization == Several approaches have been developed to analyze the location of organelles, genes, proteins, and other components within cells. A gene ontology category, cellular component, has been devised to capture subcellular localization in many biological databases.
A familiar example of the opposite, a shear thinning fluid, or pseudoplastic fluid, is wall paint: The paint should flow readily off the brush when it is being applied to a surface but not drip excessively. Note that all thixotropic fluids are extremely shear thinning, but they are significantly time dependent, whereas the colloidal "shear thinning" fluids respond instantaneously to changes in shear rate. Thus, to avoid confusion, the latter classification is more clearly termed pseudoplastic. Another example of a shear thinning fluid is blood. This application is highly favoured within the body, as it allows the viscosity of blood to decrease with increased shear strain rate.
=== Mark McVeigh Era (2026–present) === On Monday 24th of August 2026, Mark McVeigh was appointed Senior Coach of Essendon, a three year contract running through to the end of the 2029 AFL season. Club President Andrew Welsh said the decision was unanimously supported by the club board, and stating in a press release that "we have been extremely clear on the strategy and direction of this football club. We are building the next successful era for Essendon, with a view to playing finals, winning finals and competing for premierships. Mark is the best coach to take us forward to achieve that."
Sources: en.wikipedia.org
Research has focused on changing the mixture of keratins produced in the skin. There are 54 known keratin genes—of which 28 belong to the type I intermediate filament genes and 26 to type II—which work as heterodimers. Many of these genes share substantial structural and functional similarity, but they are specialized to cell type and/or conditions under which they are normally produced. If the balance of production could be shifted away from the mutated, dysfunctional keratin gene toward an intact keratin gene, symptoms could be reduced. For example, sulforaphane, a compound found in broccoli sprouts and few other vegetables, was found to reduce blistering in a mouse model to the point where affected pups could not be identified visually, when injected into pregnant mice (5 μmol/day = 0.9 mg) and applied topically to newborns (1 μmol/day = 0.2 mg in jojoba oil). As of 2008, clinical research at the University of Minnesota has explored allogeneic bone marrow transplantation for RD and junctional EB, treating a two-year-old child who is one of two brothers with EB. A second transplant has also been performed on the child's older brother. A Missouri boy has also successfully undergone the transplant, as well as a 5 year old boy from Alabama. So far there have been 12 successful transplants. Another transplant is scheduled for a California baby. A clinical trial is planned for 30 subjects. However, the immune suppression that bone marrow transplantation requires causes a risk of serious infections with large scale blisters and skin erosion.
He is currently a professor of ophthalmology at the University of Geneva, an adjunct clinical professor of ophthalmology at the Keck School of Medicine, University of Southern California, a research group leader of the Ocular Cell Biology Group at the Center for Applied Biotechnology and Molecular Medicine at the University of Zurich, a visiting professor at the University of Wenzhou, China, a research professor of ophthalmology at the NYU Grossman School of Medicine, and medical director of the ELZA Institute.
=== Entry into bacteria === Penicillin can easily enter bacterial cells in the case of gram-positive species. This is because Gram-positive bacteria do not have an outer cell membrane and are simply enclosed in a thick cell wall. Penicillin molecules are small enough to pass through the spaces of glycoproteins in the cell wall. For this reason Gram-positive bacteria are very susceptible to penicillin (as first evidenced by the discovery of penicillin in 1928). Penicillin, or any other molecule, enters gram-negative bacteria in a different manner. The bacteria have thinner cell walls but the external surface is coated with an additional cell membrane, called the outer membrane. The outer membrane is a lipid layer (lipopolysaccharide chain) that blocks passage of water-soluble (hydrophilic) molecules like penicillin. It thus acts as the first line of defence against any toxic substance, which is the reason for relative resistance to antibiotics compared to gram-positive species. But penicillin can still enter gram-negative species by diffusing through aqueous channels called porins (outer membrane proteins), which are dispersed among the fatty molecules and can transport nutrients and antibiotics into the bacteria. Porins are large enough to allow diffusion of most penicillins, but the rate of diffusion through them is determined by the specific size of the drug molecules. For instance, penicillin G is large and enters through porins slowly; while smaller ampicillin and amoxicillin diffuse much faster.
Sources: en.wikipedia.org
After being absorbed in the small intestine, iron travels through blood, bound to transferrin, and eventually ends up in the bone marrow, where it is involved in red blood cell formation. When red blood cells are degraded, the iron is recycled by the body and stored. When the amount of iron needed by the body exceeds the amount of iron that is readily available, the body can use iron stores (ferritin) for a period of time, and red blood cell formation continues normally. However, as these stores continue to be used, iron is eventually depleted to the point that red blood cell formation is abnormal. Ultimately, anemia ensues, which by definition is a hemoglobin lab value below normal limits.
Haemophilus influenzae (formerly called Pfeiffer's bacillus or Bacillus influenzae) is a Gram-negative, non-motile, coccobacillary, facultatively anaerobic, capnophilic pathogenic bacterium of the family Pasteurellaceae. The bacteria are mesophilic and grow best at temperatures between 35 and 37 °C. H. influenzae was first described in 1893 by Richard Pfeiffer during an influenza pandemic when he incorrectly identified it as the causative microbe, which is why the bacterium was given the name "influenzae". H. influenzae is responsible for a wide range of localized and invasive infections, typically in infants and children, including pneumonia, meningitis, or bloodstream infections. Treatment consists of antibiotics; however, H. influenzae is often resistant to the penicillin family, but amoxicillin/clavulanic acid can be used in mild cases. Serotype B H. influenzae (hib) can cause illness, called Hib infections, among other names. It has been a major cause of meningitis in infants and small children, frequently causing deafness and mental degradation. However, the development in the 1980s of a vaccine effective in this age group (the Hib vaccine) has almost eliminated this in developed countries. This species was the first organism to have its entire genome sequenced.
== External links == "P2Y Receptors: P2Y11". IUPHAR Database of Receptors and Ion Channels. International Union of Basic and Clinical Pharmacology. Archived from the original on 2016-03-03. Retrieved 2008-12-09. This article incorporates text from the United States National Library of Medicine, which is in the public domain.
=== Aviptadil === In the wake of the COVID-19 pandemic, scientists at Relief conducted initial studies into the efficacy of RLF-100 in treating severe COVID-19 patients. In June 2020, the U.S. Food and Drug Administration granted fast-track designation to RLF-100 for treatment of respiratory distress in COVID-19. In September 2020, Relief partnered with US-Israeli firm NRX Pharmaceuticals (formerly NeuroRx Inc) for the co-development of the drug and the co-ordination of US trials. In April 2021, a reformulated version of aviptadil, known as Zyesami, was included in a National Institutes of Health (NIH) sponsored Phase 3 trial with the aim of testing aviptadil against remdesivir. In May 2021, NRX submitted a request for an Emergency Use Authorization (EUA) to the US FDA for aviptadil's use in patients in intensive care. On 7 October 2021 Relief Therapeutics filed a lawsuit against NRX Pharmaceuticals and its CEO Dr. Jonathan Javitt in the Supreme Court of the State of New York, citing multiple alleged breaches of the collaboration agreement signed by the two companies for the co-development of aviptadil. On 4 November 2021 the FDA declined EUA for the drug, but committed to working with NRX to further develop it. On 29 November 2021, NRX announced that data analysis from the NIH-sponsored Phase 3 trial showed a fourfold increase in survival at 60 days for patients administered with Zyesami (Aviptadil) vs those who received placebo.
Sources: en.wikipedia.org
It originated at the Institute of Molecular Genetics in Moscow during the 1980s. The work was carried out by a Russian research group that specialized in peptide neuropharmacology.
It is registered as a medicine in Russia and has been used clinically there for decades. No regulatory agency in Western Europe or North America has approved it for any indication.
Semax corresponds to the four-to-ten fragment of adrenocorticotropic hormone. Because it omits the first three residues, it lacks the adrenal-stimulating action of the full hormone.
Reversed-phase HPLC gives the main purity figure, most often with UV detection near 214 nanometres. Mass spectrometry then confirms the molecular mass. Together the two methods distinguish a correct sequence from a closely related impurity.