Semax 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 2026-03-08 and is reviewed periodically as new material appears.
Identity and purity are commonly assessed by reversed-phase high-performance liquid chromatography, with ultraviolet detection near 214 nanometers for the peptide backbone. Mass spectrometry, either electrospray or matrix-assisted laser desorption, confirms molecular mass and detects truncation or modification products. Amino acid analysis can verify composition. Because the sequence contains no strongly absorbing aromatic residue apart from phenylalanine, detection wavelengths are chosen carefully. Purity values above 95 percent are typical for research-grade material.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Typical purity | ≥95% by HPLC | Research-grade material |
| Detection wavelength | 214 nm | Peptide bond absorbance |
| Reconstitution medium | Sterile water or saline | Prepare fresh or aliquot immediately |
| Storage (solution) | -80 °C, single-use aliquots | Avoid repeated freeze-thaw cycles |
| Common salt form | Acetate or trifluoroacetate | Affects mass and solubility |
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.
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.
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.
A variable pathlength cell is a sample holder used for ultraviolet–visible spectroscopy or infrared spectroscopy that has a path length that can be varied to change the absorbance without changing the sample concentration.
Bicalutamide: A pure antiandrogen. It is effective similarly to flutamide but is much safer as well as better-tolerated. Birth control pills that consist of an estrogen, usually ethinylestradiol, and a progestin are supported by the evidence. They are functional antiandrogens. In addition, certain birth control pills contain a progestin that also has antiandrogenic activity. Examples include birth control pills containing cyproterone acetate, chlormadinone acetate, drospirenone, and dienogest. Cyproterone acetate: A dual antiandrogen and progestogen. In addition to single form, it is also available in some formulations of combined oral contraceptives at a low dosage (see below). It has a risk of liver damage. Eflornithine: Blocks putrescine that is necessary for the growth of hair follicles. Finasteride and dutasteride: 5α-Reductase inhibitors. They inhibit the production of the potent androgen DHT. A meta-analysis showed inconsistent results of finasteride in the treatment of hirsutism. Flutamide: A pure antiandrogen. It has been found to possess equivalent or greater effectiveness than spironolactone, cyproterone acetate, and finasteride in the treatment of hirsutism. However, it has a high risk of liver damage and hence is no longer recommended as a first- or second-line treatment. Flutamide is safe and effective. GnRH analogues: Suppress androgen production by the gonads and reduce androgen concentrations to castrate levels. Metformin: Insulin sensitizer.
=== Present-day === 2025 Military and Security Developments Involving the People's Republic of China (PDF). Arlington, Virginia: United States Department of Defense. 2025. (China Military Power Report, Annual Report to Congress) Chase, Michael S.; Jeffery, Engstrom; Cheung, Tai Ming; Gunness, Kristen A.; Harold, Scott; Puska, Susan; Berkowitz, Samuel K. (2015). China's Incomplete Military Transformation: Assessing the Weaknesses of the People's Liberation Army (PLA). RAND Corporation. ISBN 9780833088307. Fisher, Richard D. (2008). China's Military Modernization: Building for Regional and Global Reach. Praeger Security International. ISBN 9780275994860. Kamphausen, Roy; Lai, David; Scobell, Andrew (2009). Beyond the Strait: PLA Missions Other Than Taiwan. Strategic Studies Institute. ISBN 9781304886385.
Corals' many colors give it appeal for necklaces and other jewelry. Intensely red coral is prized as a gemstone. Sometimes called fire coral, it is not the same as fire coral. Red coral is very rare because of overharvesting. In general, it is inadvisable to give coral as gifts since they are in decline from stressors like climate change, pollution, and unsustainable fishing. Always considered a precious mineral, "the Chinese have long associated red coral with auspiciousness and longevity because of its color and its resemblance to deer antlers (so by association, virtue, long life, and high rank". It reached its height of popularity during the Manchu or Qing Dynasty (1644–1911) when it was almost exclusively reserved for the emperor's use either in the form of coral beads (often combined with pearls) for court jewelry or as decorative Penjing (decorative miniature mineral trees). Coral was known as shanhu in Chinese. The "early-modern 'coral network' [began in] the Mediterranean Sea [and found its way] to Qing China via the English East India Company". There were strict rules regarding its use in a code established by the Qianlong Emperor in 1759. By the middle of the 19th century, "coral fisheries" existed in the Mediterranean, the Red Sea, Persian Gulf and elsewhere. An instrument used to retrieve the coral consisted of two beams of heavy wood attached to each other at right angles. Heavy stones were added to make the apparatus sink and netting was attached beneath the device.
Deamidation is the reaction by which a glutamate residue is formed by cleavage of the epsilon-amino group of a glutamine side chain. Transamidation is the cross-linking of a glutamine residue from the gliadin peptide to a lysine residue of tTg in a reaction that is catalysed by the transglutaminase. Cross-linking may occur either within or outside the active site of the enzyme. The latter case yields a permanently covalently linked complex between the gliadin and the tTg. This results in the formation of new epitopes believed to trigger the primary immune response of the autoantibodies against tTg. Stored biopsies from people with suspected coeliac disease have revealed that autoantibody deposits in the subclinical coeliacs are detected before clinical disease.
Sources: en.wikipedia.org
The sound can be heard by pressing a highly tensed muscle against the ear, again a firm fist is a good example. The sound is usually described as a rumbling sound. Some individuals can voluntarily produce this rumbling sound by contracting the tensor tympani muscle of the middle ear. The rumbling sound can also be heard when the neck or jaw muscles are highly tensed.
== Structural diversity of lipids == Lipids are a diverse and ubiquitous group of compounds which have many key biological functions, such as acting as structural components of cell membranes, serving as energy storage sources and participating in signaling pathways. Lipids may be broadly defined as hydrophobic or amphipathic small molecules that originate entirely or in part from two distinct types of biochemical subunits or "building blocks": ketoacyl and isoprene groups. The huge structural diversity found in lipids arises from the biosynthesis of various combinations of these building blocks. For example, glycerophospholipids are composed of a glycerol backbone linked to one of approximately 10 possible headgroups and also to 2 fatty acyl/alkyl chains, which in turn may have 30 or more different molecular structures. In practice, not all possible permutations are detected experimentally, due to chain preferences depending on the cell type and also to detection limits - nevertheless several hundred distinct glycerophospholipid molecular species have been detected in mammalian cells. Plant chloroplast thylakoid membranes however, have unique lipid composition as they are deficient in phospholipids. Also, their largest constituent, monogalactosyl diglyceride or MGDG, does not form aqueous bilayers. Nevertheless, dynamic studies reveal a normal lipid bilayer organisation in thylakoid membranes.
== Construction of the Cologne mosque (2007) == On June 4, 2007, Kermani published a report in the Süddeutsche Zeitung about a public hearing on the construction of a mosque in the district of Cologne-Ehrenfeld. In the report, Kermani expressed enthusiasm for the open atmosphere of discussion. Attesting that the citizens present embodied "democracy in its purest form", Kermani noted that there is a "broad, cosmopolitan middle" in Cologne whose members are far more tolerant than many intellectuals.
=== Chemical synthesis === Digital Microfluidics (DMF) allows for precise manipulation and coordination in small-scale chemical synthesis reactions due to its ability to control micro scale volumes of liquid reagents, allowing for overall less reagent use and waste. This technology can be used in the synthesis compounds such as peptidomimetics and PET tracers. PET tracers require nanogram quantities and as such, DMF allows for automated and rapid synthesis of tracers with 90-95% efficiency compared to conventional macro-scale techniques. Organic reagents are not commonly used in DMF because they tend to wet the DMF device and cause flooding; however synthesis of organic reagents can be achieved through DMF techniques by carrying the organic reagents through an ionic liquid droplet, thus preventing the organic reagent from flooding the DMF device. Droplets are combined together by inducing opposite charges thus attracting them to each other. This allows for automated mixing of droplets. Mixing of droplets are also used to deposit MOF crystals for printing by delivering reagents into wells and evaporating the solutions for crystal deposition. This method of MOF crystal deposition is relatively cheap and does not require extensive robotic equipment. Chemical synthesis using digital microfluidics (DMF) has been applied to many noteworthy biological reactions. These include polymerase chain reaction (PCR), as well as the formation of DNA and peptides.
==== United States ==== 4-HO-DPT is not an explicitly controlled substance in the United States. However, the drug is a close analogue of psilocin (4-HO-DMT), which is a Schedule I controlled substance in this country, and hence sale for intended human consumption could be illegal under the Federal Analogue Act.
Sources: en.wikipedia.org
=== Rowing === New Zealand Secondary School Championships (Maadi Cup) Maadi Cup (boys' U18 eight) – Westlake Boys High School Levin Jubilee Cup (girls' U18 eight) – St Margaret's College Star Trophy (overall points) – King's College
In April 1921, using the "well-equipped, funded laboratory" of John Macleod at the Physiology Department of the University of Toronto, Frederick Banting and Charles Best began investigating processes through which "the active principle of the extracts of degenerated [bovine] pancreas" could potentially be preserved without being destroyed (as was the case with the (then) current extraction processes).
Unable to afford the TCB Band, the group featured guitarists Jock Bartley and Larry Coryell, Neil Flanz on pedal steel, bassist Kyle Tullis, and drummer N. D. Smart. The touring party also included Parsons' new wife, Gretchen Parsons, who was envious of Harris and her young daughter. Coordinating the spectacle as road manager was Phil Kaufman, who had served time with Charles Manson on Terminal Island but who ensured that the performer stayed clear of drugs and limited his alcohol intake during shows. At first, the band was under-rehearsed and played poorly; however, they improved with steady gigging and received rapturous responses at several counter-cultural venues, including Armadillo World Headquarters in Austin, Max's Kansas City in New York City, and Liberty Hall in Houston, where Neil Young and Linda Ronstadt sat in for a filmed performance. Nevertheless, the tour failed to galvanize sales of GP, which never charted in the Billboard 200. For his next and final album, 1974's posthumously released Grievous Angel, Parsons used Harris and members of the TCB Band. The record received more enthusiastic reviews than GP. Although Parsons only contributed two new songs to the album ("In My Hour of Darkness" and "Return of the Grievous Angel"), he was reportedly enthusiastic with his new sound and seemed to have finally adopted a diligent mindset to his musical career, limiting his intake of alcohol and opiates during most of the sessions. Grievous Angel peaked at number 195 on the Billboard chart.
This process is referred to as acclimatization: the maximum rate of sweating increases and its solute composition decreases. The volume of water lost in sweat daily is highly variable, ranging from 100 to 8,000 millilitres per day (0.041 to 3.259 imp fl oz/ks). The solute loss can be as much as 350 mmol/d (or 90 mmol/d acclimatised) of sodium under the most extreme conditions. During average intensity exercise, sweat losses can average up to 2 litres (0.44 imp gal; 0.53 US gal) of water/hour. In a cool climate and in the absence of exercise, sodium loss can be very low (less than 5 mmol/d). Sodium concentration in sweat is 30–65 mmol/L, depending on the degree of acclimatisation. Horses have a thick, waterproofed, hairy coat that would normally block the rapid translocation of sweat water from the skin to the surface of the hair required for evaporative cooling. To solve this, horses have evolved a detergent-like protein, latherin, that they release at high concentrations in their sweat. Their perspiration unlike humans is created by apocrine glands. This protein, by wetting the horses' coat hairs facilitate water flow for cooling evaporation. The presence of this protein can be seen in the lathering that often occurs on the coats of sweating horses, especially when rubbed. In hot conditions, horses during three hours of moderate-intensity exercise can lose 30 to 35 litres (6.6 to 7.7 imp gal; 7.9 to 9.2 US gal) of water and 100 grams (3.5 oz) of sodium, 198 grams (7.0 oz) of chloride and 45 grams (1.6 oz) of potassium.
Sources: en.wikipedia.org
Solid peptide is best kept frozen at about minus 20 degrees Celsius in a sealed container with desiccant. It should be allowed to reach room temperature before opening to prevent condensation. Repeated warming and cooling of the same vial is discouraged.
Reversed-phase liquid chromatography establishes purity, while mass spectrometry confirms molecular mass. The two techniques are normally used together. Retention time alone is not sufficient evidence of identity.
Different counterions change the mass per unit of peptide and can shift chromatographic behavior. Two samples of equal stated purity may therefore not be directly comparable. Reports should specify the counterion whenever quantitative comparisons are made.
Semax is based on the ACTH(4-10) fragment, a seven-amino-acid segment of adrenocorticotropic hormone. The synthetic peptide retains the core sequence while removing regions associated with endocrine activity. This modification is intended to isolate effects on the nervous system.