A practical reference on Semax: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-02-23 and is reviewed periodically as new material appears.
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.
Laboratory work points toward modulation of neurotrophic signaling, particularly expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal tissue. Studies also describe effects on monoamine turnover, inflammatory mediators, and oxidative markers. These observations come mainly from animal models and cultured cells, so the causal chain in humans is not firmly established. Whether the reported molecular changes translate into measurable clinical benefit is an open question. Reviews generally present the mechanism as plausible rather than demonstrated.
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.
| Property | Value | Notes |
|---|---|---|
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Heptapeptide; ACTH(4-10) analog extended at C-terminus |
| Molecular mass | ~813.9 Da | Free peptide, unmodified |
| Appearance | White to off-white powder | Typical lyophilized solid |
| Solubility | Soluble in water and saline | Also soluble in common aqueous buffers |
| Storage (solid) | -20 °C, desiccated | Protect from moisture and repeated thawing |
Reported pharmacological work centers on neurotrophic signaling, including changes in BDNF and NGF expression in hippocampal tissue in animal models. Human data come largely from studies conducted in Russia, and how well those results generalize to other populations remains an open question. Regulatory status differs sharply by jurisdiction: Semax is a registered prescription medicine in Russia, while it holds no approved marketing status in the United States or the European Union. Outside such jurisdictions it is generally handled as a research chemical, which affects both documentation and quality expectations.
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.
Development of the compound took place in the Soviet Union during the 1980s, largely through peptide research groups affiliated with the Shemyakin-Ovchinnikov Institute and Moscow State University. Investigators screened fragments of adrenocorticotropic hormone for activity on the central nervous system while attempting to separate cognitive effects from hormonal ones. The shortened sequence was selected because it retained behavioral activity in animal models without stimulating corticosteroid release. Early publications described the molecule as an ACTH(4-10) analog.
Published research on this peptide originates mainly from Russian laboratories, and the wider international literature is comparatively thin. Studies have used rodent models of stroke, hypoxia, and memory tasks, with a smaller number of human trials reported. Reported outcomes include changes in attention and memory measures, along with effects on neurotrophic factor expression in some experiments. Small sample sizes, inconsistent dosing protocols, and limited independent replication are widely noted limitations, so the strength of the clinical evidence remains an open question.
== Taxonomy == HHV-6A and HHV-6B were recognized by the International Committee on Taxonomy of Viruses (ICTV) as distinct species in 2012. Human roseoloviruses include HHV-6A, HHV-6B and HHV-7. Herpesvirus was established as a genus in 1971 in the first report of the ICTV. This genus consisted of 23 viruses among 4 groups. In 1976, a second ICTV report was released in which this genus was elevated to the family level — the herpetoviridae. Because of possible confusion with viruses derived from reptiles, the family name was changed in the third report (1979) to herpesviridae. In this report, the family Herpesviridae was divided into 3 subfamilies (alphaherpesvirinae, betaherpesvirinae and gammaherpesvirinae) and 5 unnamed genera; 21 viruses were recognized as members of the family. In 2009, the order Herpesvirales was created. This was necessitated by the discovery that the herpes viruses of fish and molluscs are only distantly related to those of birds and mammals. Order Herpesvirales contains three families, the Herpesviridae, which contains the long-recognized herpesviruses of mammals, birds, and reptiles, plus two new families — the family Alloherpesviridae which incorporates herpes viruses of bony fish and frogs, and the family Malacoherpesviridae which contains viruses of molluscs. As of 2012, this order currently has 3 families, 4 subfamilies (1 unassigned), 18 genera (4 unassigned) and 97 species.
== Mutations == Mitochondrial acetoacetyl-CoA thiolase, also known as thiolase II, the enzyme responsible for catalyzing the synthesis of acetoacetyl-CoA within ketogenesis as mentioned, is also involved within acetoacetyl-CoA cleavage in ketolysis. It is observed to play a role within cleavage of acetyl-CoA from acetoacetyl-CoA and 2-methylacetoacetyl-CoA. The enzyme is involved in an autosomal recessive disorders that impacts the catabolism of ketone bodies and isoleucine: beta-ketothiolase deficiency, leading to their deficiency within mitochondria. The mutation takes place within the acetoacetyl-CoA thiolase (ACAT) gene mapped on chromosome 11q22.3-23.1. Mutations in mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase (HMG-CoA synthase) is another inherited autosomal recessive disorder affecting the catabolism of ketone bodies and can lead to the build-up of acetoacetyl-CoA.
1993/1661) Immigration Appeals (Procedure) (Amendment) Rules 1993 (S.I. 1993/1662) Offshore Installations (Safety Zones) (No. 2) Order 1993 (S.I. 1993/1664) Recreation Grounds (Revocation of Parish Council Byelaws) Order 1993 (S.I. 1993/1665) Merchant Shipping (Fees) (Amendment) (No. 2) Regulations 1993 (S.I. 1993/1676) Export of Goods (Control) (Haiti) Order 1993 (S.I. 1993/1677) Immigration (Transit Visa) Order 1993 (S.I. 1993/1678) Income Support (General) Amendment No. 3 Regulations 1993 (S.I. 1993/1679) Merchant Shipping (Prevention of Oil Pollution) (Amendment) Regulations 1993 (S.I. 1993/1680) Merchant Shipping (Prevention of Pollution by Garbage) (Amendment) Regulations 1993 (S.I. 1993/1681) Diseases of Animals (Seizure) Order 1993 (S.I. 1993/1685) Road Traffic Act 1991 (Commencement No. 6 and Transitional Provisions) (Amendment) Order 1993 (S.I. 1993/1686) Football Spectators Act 1989 (Commencement No. 4) Order 1993 (S.I. 1993/1690) Football Spectators (Designation of Football Matches in England and Wales) Order 1993 (S.I. 1993/1691) Export of Goods (Control) (Amendment No. 2) Order 1993 (S.I. 1993/1692) Road Traffic Offenders (Prescribed Devices) Order 1993 (S.I. 1993/1698)
== Prevention == Researchers found environmental reservoirs of CRE bacteria in ICU sinks and drains. Despite multiple attempts to sterilize these sinks and drains, using detergents and steam, the hospital staff was unsuccessful in getting rid of the CRE. Due to the bacterial resistance to cleaning measures, staff should take extreme precaution in maintaining sterile environments in hospitals not yet infected with the CRE-resistant bacteria. A major means of transmission is through sinks, so staff should take extra precaution in maintaining sterile conditions. Hospitals could reduce transmission by creating sinks with designs that could reduce backsplash. Another method to reduce transmission from sink to sink is to have sink brushes in each room that would be for cleaning that individual sink alone. Hospital staff should be trained to never dispose of clinical waste down the sinks in patient rooms. A hospital in Melbourne, Australia, implemented similar strategies as these to reduce transmission and prevent further infection of more ICU patients. Armed with the knowledge of their status as CRE transmission sites, hospitals must take special care to monitor CRE outbreaks within their wards. Efficient and accurate detection of CRE is the first step. Enterobacteriaceae are most commonly found in the intestinal flora. Using stool and rectal swabs are, thus, the most reliable methods for testing resistance. No billing code exists for CRE under Medicare or Medicaid, making it difficult to track on a national level in the U.S.
Sources: en.wikipedia.org
==== Children and pregnancy ==== Although acupuncture has been practiced for thousands of years in China, its use in pediatrics in the United States did not become common until the early 2000s. In 2007, the National Health Interview Survey (NHIS) conducted by the National Center For Health Statistics (NCHS) estimated that approximately 150,000 children had received acupuncture treatment for a variety of conditions. In 2008, a study determined that the use of acupuncture-needle treatment on children was "questionable" due to the possibility of adverse side-effects and the pain manifestation differences in children versus adults. The study also includes warnings against practicing acupuncture on infants, as well as on children who are over-fatigued, very weak, or have over-eaten. When used on children, acupuncture is considered safe when administered by well-trained, licensed practitioners using sterile needles; however, a 2011 review found there was limited research to draw definite conclusions about the overall safety of pediatric acupuncture. The same review found 279 adverse events, 25 of them serious. The adverse events were mostly mild in nature (e.g., bruising or bleeding). The prevalence of mild adverse events ranged from 10.1% to 13.5%, an estimated 168 incidences among 1,422 patients. On rare occasions adverse events were serious (e.g. cardiac rupture or hemoptysis); many might have been a result of substandard practice. The incidence of serious adverse events was 5 per one million, which included children and adults.
== History == Before the causes of PKU were understood, PKU caused severe disability in most people who inherited the relevant mutations. Nobel and Pulitzer Prize-winning author Pearl S. Buck had a daughter named Carol who lived with PKU before treatment was available, and wrote an account of its effects in a book called The Child Who Never Grew. Many untreated PKU patients born before widespread newborn screening are still alive, largely in dependent living homes/institutions. Phenylketonuria was discovered by the Norwegian physician Ivar Asbjørn Følling in 1934 when he noticed hyperphenylalaninemia (HPA) was associated with intellectual disability. In Norway, this disorder is known as Følling's disease, named after its discoverer. Følling was one of the first physicians to apply detailed chemical analysis to the study of disease. In 1934 at Rikshospitalet, Følling saw a young woman named Borgny Egeland. She had two children, Liv and Dag, who had been normal at birth but subsequently developed intellectual disability. When Dag was about a year old, the mother noticed a strong smell in his urine. Følling obtained urine samples from the children and, after many tests, he found that the substance causing the odor in the urine was phenylpyruvic acid. The children, he concluded, had excess phenylpyruvic acid in the urine, the condition which came to be called phenylketonuria (PKU). His analysis of the urine of the two affected siblings led him to request many physicians near Oslo to test the urine of other affected patients.
== Fiber types == Broadly there are two types of muscle fiber: Type I, which is slow, and Type II which are fast. Type II has two divisions of type IIA (oxidative), and type IIX (glycolytic), giving three main fiber types. These fibers have relatively distinct metabolic, contractile, and motor unit properties. The table below differentiates these types of properties. These types of properties—while they are partly dependent on the properties of individual fibers—tend to be relevant and measured at the level of the motor unit, rather than at the individual fiber.
Nonetheless, there are indications that the Greeks had an open mind about large penises. A statue of the god Hermes with an exaggerated penis stood outside the main gate of Athens and in Alexandria in 275 BC, a procession in honor of Dionysus hauled a 180-foot phallus through the city and people venerated it by singing hymns and reciting poems. The Romans, in contrast to the Greeks, seem to have admired large penises and many large phalli have been recovered from the ruins of Pompeii. Depictions of Priapus were very popular in Roman erotic art and literature. Over eighty obscene poems dedicated to him have survived. Penis size is alluded to in the Bible:
=== Natural Killer T-cells === Natural killer T-cells (NKT cells) can also be visualized with tetramer technology. NKT cells bind to proteins that present lipid or glycolipid antigens. The antigen presenting complex that NKT cells bind to involves CD1 proteins, so tetramers made of CD1 can be used to stain for NKT cells.
Sources: en.wikipedia.org
In Europe the field followed its own pathway; for example in Germany the parallel interventional society began to break free of the DR society in 2008. In the UK, interventional radiology was approved as a sub-specialty of clinical radiology in 2010. While many countries have an interventional radiology society, there is also the European-wide Cardiovascular and Interventional Radiological Society of Europe, whose aim is to support teaching, science, research and clinical practice in the field by hosting meetings, educational workshops and promoting patient safety initiatives. Furthermore, the Society provides an examination, the European Board of Interventional Radiology (EBIR), which is a highly valuable qualification in interventional radiology based on the European Curriculum and Syllabus for IR.
The sermon images were "of pure Gandhara style". Their style was very close to those of the "Cave of the Painters (Cave 207)", and, according to Grünwedel, "they seem to have been executed by the same hand". Albert Grünwedel attributed both caves to the same "Stage I" period (500–600 CE). Several fine fragments of very fine painting have reached us, which are attributed to the Cave of the Statues. Grünwedel explained that only three paintings remained in the cella, all scenes of the sermon of the Buddha: 1) On the right wall of the cella, Grünwedel described the picture of a sermon, with "a youth in light undergarment praying in front of Buddha", corresponding to the picture now described as the "cowherd Nanda", known to have come from the Cave of the Statues. 2) In the opposite location, on the left wall, Grünwedel described a sermon scene in which the Buddha "only had his feet remaining", corresponding to the panel photographed by Charles Nouette in-situ in 1907. 3) Finally Grünwedel described a sermon scene with only a "kneeling adorant" remaining, corresponding to the kneeling Vajrapani, known to have come from the Cave of the Statues. The style of these panels from the main cella is markedly different from the refined, "classical" style of the side corridor vaults and the back corridor. They suggests different painters and different schools of art. In the cella, the paintings are much bolder, using intense colors, thicker lines and simpler patterns, as in the "Cowherd Nanda".
Intussusceptive angiogenesis, also known as splitting angiogenesis, is the formation of a new blood vessel by splitting an existing blood vessel into two. Intussusception was first observed in neonatal rats. In this type of vessel formation, the capillary wall extends into the lumen to split a single vessel in two. There are four phases of intussusceptive angiogenesis. First, the two opposing capillary walls establish a zone of contact. Second, the endothelial cell junctions are reorganized and the vessel bilayer is perforated to allow growth factors and cells to penetrate into the lumen. Third, a core is formed between the 2 new vessels at the zone of contact that is filled with pericytes and myofibroblasts. These cells begin laying collagen fibers into the core to provide an extracellular matrix for growth of the vessel lumen. Finally, the core is fleshed out with no alterations to the basic structure. Intussusception is important because it is a reorganization of existing cells. It allows a vast increase in the number of capillaries without a corresponding increase in the number of endothelial cells. This is especially important in embryonic development as there are not enough resources to create a rich microvasculature with new cells every time a new vessel develops.
Californium exhibits oxidation states of 4, 3, or 2. It typically forms eight or nine bonds to surrounding atoms or ions. Its chemical properties are predicted to be similar to other primarily 3+ valence actinide elements and the element dysprosium, which is the lanthanide above californium in the periodic table. Compounds in the +4 oxidation state are strong oxidizing agents and those in the +2 state are strong reducing agents. The element slowly tarnishes in air at room temperature, with the rate increasing when moisture is added. Californium reacts when heated with hydrogen, nitrogen, or a chalcogen (oxygen family element); reactions with dry hydrogen and aqueous mineral acids are rapid. Californium is only water-soluble as the californium(III) cation. Attempts to reduce or oxidize the +3 ion in solution have failed. The element forms a water-soluble chloride, nitrate, perchlorate, and sulfate and is precipitated as a fluoride, oxalate, or hydroxide. Californium is the heaviest actinide to exhibit covalent properties, as is observed in californium borate.
Sources: en.wikipedia.org
Semax is a synthetic seven-amino-acid peptide derived from a fragment of corticotropin. It is used in Russia as a nasal preparation, while elsewhere it is studied as a research compound. It is not approved as a medicine in most countries.
Its sequence corresponds to the 4-10 region of corticotropin extended by three residues. This fragment lacks the region responsible for adrenal steroid release, so it is explored for neural rather than hormonal effects. The relationship explains the compound's classification among ACTH-derived peptides.
It holds approval in Russia for several neurological indications as a nasal spray or drop formulation. Regulatory agencies in the United States and the European Union have not approved it. Products sold elsewhere are generally labeled for research use only.
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.