ACTH(4-10) 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 2026-08-01 and is reviewed periodically as new material appears.
Pharmacokinetic accounts emphasize rapid breakdown. After intravenous dosing the intact peptide disappears from blood within minutes, and nasal delivery produces low but measurable concentrations. Metabolites rather than the parent molecule may account for part of the observed activity, although the relative contribution is unresolved. Dosing in the literature varies widely and no optimal schedule has been agreed. These gaps are regularly cited as a reason the findings have not produced broad clinical adoption beyond the original research setting.
Proposed mechanisms center on neurotrophic signaling rather than on classical melanocortin receptor activation. Rodent experiments have reported shifts in the expression of brain-derived neurotrophic factor and nerve growth factor after administration, together with changes in the associated receptor systems. Several authors argue that the peptide acts largely through its degradation products and their interaction with peptidergic pathways, but this remains a hypothesis rather than a settled finding. No single molecular target has been identified in a way that the field broadly accepts.
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.
| Property | Value | Notes |
|---|---|---|
| Primary research models | Rodent studies | Largest share of published data |
| Reported markers | BDNF and NGF expression | Measured mainly in animal tissue |
| Common administration | Intranasal | Matches the registered formulation |
| Blood residence time | Minutes | Rapid enzymatic degradation |
| Evidence quality | Small trials, limited replication | Noted repeatedly in reviews |
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.
Semax is supplied as a lyophilized powder that appears white to off-white. It dissolves readily in water, phosphate-buffered saline, and other aqueous media, which simplifies preparation of working solutions for laboratory use. The nasal products registered in Russia are dilute aqueous solutions, typically around 0.1 percent peptide by weight. Organic solvents are rarely necessary and can complicate handling. Because the peptide is hygroscopic, weighing should be performed quickly and with minimal exposure to ambient humidity.
Solid material is normally kept at minus 20 degrees Celsius in a sealed, desiccated container. Reconstituted solutions are less stable and are usually divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are avoided because they promote aggregation and loss of activity. Light exposure is minimized by using amber glassware or foil wrapping. Published stability data for this peptide are sparse, so recommended storage conditions rest mainly on general practice for short synthetic peptides rather than on dedicated study.
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.
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.
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.
Scientific literature on semax is unevenly distributed. A substantial share of published work originates from a small number of laboratories in Russia, while independent replication elsewhere is limited. Human data consist mostly of small trials with short follow-up, and several reported outcomes rely on subjective rating scales. Questions about how much intact peptide reaches the central nervous system after nasal administration, and how long it persists there, are still unresolved. The compound is best described as an active research subject rather than a settled pharmacological agent.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It was derived from the ACTH(4-10) fragment, a short segment of adrenocorticotropic hormone that lacks the hormonal activity associated with the full-length peptide. Researchers at the Institute of Molecular Genetics in Moscow developed the compound during the 1980s. It has been registered as a pharmaceutical product in Russia and several neighbouring countries, where it is supplied as a nasal solution, and it is also sold internationally as a research chemical.
The proposed mechanism centres on neurotrophic signalling rather than direct receptor activation. Semax is reported to increase expression of brain-derived neurotrophic factor and nerve growth factor in several brain regions, and to shift the balance between excitatory and inhibitory neurotransmitter systems. Interaction with melanocortin receptors has been suggested because of the parent ACTH fragment. Many of these findings come from rodent studies, and the extent to which they translate to human physiology remains an open question.
==== Acquisitions and mergers ==== In June 2000, Pfizer acquired Warner-Lambert outright for $116 billion. To satisfy conditions imposed by antitrust regulators at the Federal Trade Commission, Pfizer sold off or transferred stakes in several minor products, including RID (a shampoo for treatment of head lice, sold to Bayer) and Warner-Lambert's antidepressant Celexa (which competes with Zoloft). The acquisition created what was, at the time, the second-largest pharmaceutical company worldwide. In 2003, Pfizer merged with Pharmacia, and in the process acquired Searle and SUGEN. Searle had developed Flagyl (metronidazole), a nitroimidazole antibiotic medication used particularly for anaerobic bacteria and protozoa. Searle also developed celecoxib (Celebrex) a COX-2 inhibitor and nonsteroidal anti-inflammatory drug (NSAID) used to treat the pain and inflammation in osteoarthritis, acute pain in adults, rheumatoid arthritis, ankylosing spondylitis, painful menstruation, and juvenile rheumatoid arthritis. SUGEN, a company focused on protein kinase inhibitors, had pioneered the use of ATP-mimetic small molecules to block signal transduction. The SUGEN facility was shut down in 2003 by Pfizer, with the loss of more than 300 jobs, and several programs were transferred to Pfizer. These included sunitinib (Sutent), a cancer medication which was approved for human use by the FDA in January 2006. A related compound, SU11654 (Toceranib), was also approved for cancer in dogs, and the ALK inhibitor Crizotinib also grew out of a SUGEN program.
Maurer, Maurer, ed. (1983) [1961]. Air Force Combat Units of World War II (PDF) (reprint ed.). Washington, DC: Office of Air Force History. ISBN 0-912799-02-1. LCCN 61060979. Archived from the original (PDF) on 20 December 2016. Retrieved 17 December 2016. Maurer, Maurer, ed. (1982) [1969]. Combat Squadrons of the Air Force, World War II (PDF) (reprint ed.). Washington, DC: Office of Air Force History. ISBN 0-405-12194-6. LCCN 70605402. OCLC 72556. Archived from the original (PDF) on 20 December 2016. Retrieved 17 December 2016.
The basement membrane is visible under light microscopy. Electron microscopy shows that the basement membrane consists of three layers: the lamina lucida (electron-lucent), lamina densa (electron-dense), and lamina fibro-reticularis (electron-lucent). The lamina densa was formerly called the “basal lamina”. The terms “basal lamina” and “basement membrane” were often used interchangeably, until it was realised that all three layers seen with the electron microscope constituted the single layer seen with the light microscope. This has led to considerable terminological confusion; if used, the term “basal lamina” should be confined to its meaning as lamina densa. Some theorize that the lamina lucida is an artifact created when preparing the tissue, and that the lamina lucida is therefore equal to the lamina densa in vivo. The term "basal lamina" is usually used with electron microscopy, while the term "basement membrane" is usually used with light microscopy. Examples of basement membranes include:
==== Tumoral calcinosis ==== Tumoral calcinosis is distinguished by the accumulation of calcific masses surrounding the main joints. It mainly affects teens who are otherwise in good health. Joint function may be hampered by the subcutaneous or intramuscular calcified deposits.
==== Aplastic crisis ==== Aplastic crises are instances of an acute worsening of the patient's baseline anaemia, producing pale appearance, fast heart rate, and fatigue. This crisis is normally triggered by parvovirus B19, which directly affects production of red blood cells by invading the red cell precursors and multiplying in and destroying them. Parvovirus infection almost completely prevents red blood cell production for two to three days (red cell aplasia). In normal individuals, this is of little consequence, but the shortened red cell life of people with sickle cell disease results in an abrupt, life-threatening situation. Reticulocyte count drops dramatically during the disease (causing reticulocytopenia), red cell production lapses, and the rapid destruction of existing red cells leads to acute and severe anaemia. This crisis takes four to seven days to resolve. Most patients can be managed supportively; some need a blood transfusion.
Sources: en.wikipedia.org
=== Abduction and disappearances === The Syrian Observatory for Human Rights reported that 560 people, including women and children, went missing during clashes in Suwayda. The UN reported that 105 Druze women and girls were abducted by groups affiliated with the Syrian government, with 80 of them still missing as of 21 August; in at least three cases, Druze women were raped before being murdered.
therapeutic area) might be tempted or encouraged to expand their engagement with that CRO into other, unrelated areas; however, caution is required as CROs are always seeking to expand their experience and success in one area cannot reliably predict success in unrelated areas that might be new to the organization.
TCFH (N,N,N’,N’-tetramethylchloroformamidinium hexafluorophosphate) is an electrophilic amidine reagent used to activate a number of functional groups (such as carboxylic acids) for reaction with nucleophilies. TCFH is most commonly used to activate carboxylic acids for reaction with amines in the context of amide bond formation and peptide synthesis.
Diazepam undergoes oxidative metabolism by demethylation (CYP2C9, 2C19, 2B6, 3A4, and 3A5), hydroxylation (CYP3A4 and 2C19) and glucuronidation in the liver as part of the cytochrome P450 enzyme system. It has several pharmacologically active metabolites. The main active metabolite of diazepam is desmethyldiazepam (also known as nordazepam or nordiazepam). Its other active metabolites include the minor active metabolites temazepam and oxazepam. These metabolites are conjugated with glucuronide and are excreted primarily in the urine. Because of these active metabolites, the serum values of diazepam alone are not useful in predicting the effects of the drug. Diazepam has a biphasic half-life of about one to three days and two to seven days for the active metabolite desmethyldiazepam. Most of the drug is metabolized; little diazepam is excreted unchanged. The elimination half-life of diazepam and also the active metabolite desmethyldiazepam increases significantly in the elderly, which may result in prolonged action, as well as accumulation of the drug during repeated administration.
They noted a glycerin-bile-potato mixture grew bacilli that seemed less virulent and changed the course of their research to see if repeated subculturing would produce a strain that was attenuated enough to be considered for use as a vaccine. The BCG strain was isolated after subculturing 239 times during 13 years from a virulent strain on glycerine potato medium. The research continued throughout World War I until 1919 when the now avirulent bacilli were unable to cause tuberculosis disease in research animals. Calmette and Guerin transferred to the Paris Pasteur Institute in 1919. The BCG vaccine was first used in humans in 1921. Public acceptance was slow, and the Lübeck disaster, in particular, did much to harm it. Between 1929 and 1933 in Lübeck, 251 infants were vaccinated in the first 10 days of life; 173 developed tuberculosis and 72 died. It was subsequently discovered that the BCG administered there had been contaminated with a virulent strain that was being stored in the same incubator, which led to legal action against the vaccine's manufacturers. Dr. R. G. Ferguson, working at the Fort Qu'Appelle Sanatorium in Saskatchewan, was among the pioneers in developing the practice of vaccination against tuberculosis. In Canada, more than 600 children from residential schools were used as involuntary participants in BCG vaccine trials between 1933 and 1945. In 1928, the BCG vaccine was adopted by the Health Committee of the League of Nations (predecessor to the World Health Organization (WHO)).
Sources: en.wikipedia.org
Gamow was not entirely wrong. Although his concept about the direct synthesis of amino acid from the DNA double strands was proven false, his prediction on the nature of amino acids and how they were coded by the DNA sequences (triplet nucleotides) were confirmed the key components of protein synthesis. This broad concept is now known as the genetic code. It was Crick, along with J.S. Griffith and Leslie Orgel (member of the RNA Tie Club), describing the 20-amino acid prediction as the "magic number," introduced the proper concept in 1957:[The] order of the amino acids is determined by the order of the nucleotides of the nucleic acid. There are some twenty naturally occurring amino acids commonly found in proteins, but (usually) only four different nucleotides. The problem of how a sequence of four things (nucleotides) can determine a sequence of twenty things (amino acids) is known as the 'coding' problem.As Crick was lecturing on his hypothesis, such adaptors do exist in nature was already discovered by the team of Mahlon Hoagland and Paul Zamecnik, whose paper was published the following year in March 1958. These "soluble RNAs" are now called transfer RNAs and mediate the translation of messenger RNAs on ribosomes according to the rules contained in the genetic code. Crick imagined that his adaptors would be small, perhaps 5-10 nucleotides long. In fact, they are much larger, having a more complex role to play in protein synthesis, and are closer to 100 nucleotides in length.
==== Vaal Civic Association ==== The organisation which spearheaded the 3 September march was the VCA, a residents' organisation partly modelled on the successful Soweto Civic Association. Launched on 9 October 1983, VCA was an affiliate of the UDF, and two senior officials in the UDF's Transvaal branch – Curtis Nkondo and Elliot Shabangu – were guest speakers at its launch in October 1983. Its inaugural chairman was Lord McCamel, a local priest with a parish in Evaton, and his deputy was Esau Ralitsela.
microsatellite Also short tandem repeat (STR) or simple sequence repeat (SSR). A type of satellite DNA consisting of a relatively short sequence of tandem repeats, in which certain motifs (ranging in length from one to six or more bases) are repeated, typically 5–50 times. Microsatellites are widespread throughout most organisms' genomes and tend to have higher mutation rates than other regions. They are classified as variable number tandem repeat (VNTR) DNA, along with longer minisatellites.
During most of his own life, conservationism was not yet on the political agenda, and Tolkien himself did not directly express conservationist views—except in some private letters, in which he tells about his fondness for forests and sadness at tree-felling. After his death, scholars concluded that while he was writing The Lord of the Rings, Tolkien became increasingly interested in the value of wild nature, and in protecting what was left of it in the industrialized world.
The influx of refugees troubled the Cossacks, not only because of the increased demand for food but also because their large number meant the Cossacks could not absorb them into their culture by way of the traditional apprenticeship. Instead of taking these steps for proper assimilation into Cossack society, the runaway peasants spontaneously declared themselves Cossacks and lived alongside the true Cossacks, laboring or working as barge-haulers to earn food. Divisions among the Cossacks began to emerge as conditions worsened and Mikhail's son Alexis took the throne. Older Cossacks began to settle and become prosperous, enjoying privileges earned through obeying and assisting the Muscovite system. The old Cossacks started giving up the traditions and liberties that had been worth dying for, to obtain the pleasures of an elite life. The lawless and restless runaway peasants who called themselves Cossacks looked for adventure and revenge against the nobility that had caused them suffering. These Cossacks did not receive the government subsidies that the old Cossacks enjoyed, and had to work harder and longer for food and money.
Sources: en.wikipedia.org
The main proposal is modulation of neurotrophic factors such as brain-derived neurotrophic factor, supported largely by animal experiments. Receptor-level targets have not been firmly established. Most reviews describe the mechanism as only partially characterized.
The compound is registered as a medicine in Russia, so clinical work has concentrated there. Trials elsewhere are few and generally small. This geographic concentration is a recognized limitation in evidence reviews.
Some fraction may reach the central nervous system through olfactory pathways, and this is often cited as the rationale for the nasal route. The size of that fraction in humans is not well quantified. Blood concentrations after nasal dosing are low, which complicates measurement.
The sequence is Met-Glu-His-Phe-Pro-Gly-Pro, a seven-residue peptide. The first four residues correspond to the ACTH(4-10) fragment, and Pro-Gly-Pro is added at the C-terminus. N-acetylated versions also appear in the literature and differ in mass.