Semax comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2025-11-26. Numbers and descriptions here follow the published literature rather than marketing material.
The C-terminal Pro-Gly-Pro extension is not incidental. Proline-rich tails are known to resist several common peptidases, and the published literature attributes the longer half-life of Semax, relative to unmodified ACTH fragments, to this feature. The modification also removes the melanocyte-stimulating and corticosteroidogenic activity that characterizes longer ACTH-derived sequences. Because the molecule is small and hydrophilic, it is typically formulated as an aqueous solution for intranasal or parenteral delivery. Acetylation or amidation at the termini appears in closely related research peptides and shifts the mass by a fixed increment.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular weight | ~813.9 Da (free heptapeptide) | N-acetylated form is about 42 Da heavier |
| Residue count | 7 (heptapeptide) | Four residues from ACTH(4-10), three added |
| Appearance | White to off-white powder | Usually supplied lyophilized |
| Solubility class | Freely soluble in water | Also dissolves in DMSO and polar organic solvents |
| Related parent fragment | ACTH(4-10) | Parent motif is Met-Glu-His-Phe |
The parent fragment ACTH(4-10) carries the sequence Met-Glu-His-Phe-Arg-Trp-Gly. Semax replaces the arginine and tryptophan positions with a proline-glycine-proline tail, giving Met-Glu-His-Phe-Pro-Gly-Pro. That change removes residues associated with adrenal stimulation, so the peptide does not drive cortisol release the way full ACTH does. This distinction shapes how the compound is grouped in the literature, where it sits with neuropeptides and peptide neuromodulators rather than with corticosteroids.
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 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.
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.
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.
== In-gel digestion == Afterwards the eponymous step of the method is performed, the in-gel digestion of the proteins. By this procedure, the protein is cut enzymatically into a limited number of shorter fragments. These fragments are called peptides and allow for the identification of the protein with their characteristic mass and pattern. The serine protease trypsin is the most common enzyme used in protein analytics. Trypsin cuts the peptide bond specifically at the carboxyl end of the basic aminoacids arginine and lysine. If there is an acidic amino acid like aspartic acid or glutamic acid in direct neighborhood to the cutting site, the rate of hydrolysis is diminished, a proline C-terminal to the cutting site inhibits the hydrolysis completely. An undesirable side effect of the use of proteolytic enzymes is the self digestion of the protease. To avoid this, in the past Ca2+-ions were added to the digestion buffer. Nowadays most suppliers offer modified trypsin where selective methylation of the lysines limits the autolytic activity to the arginine cutting sites. Unmodified trypsin has its highest activity between 35 °C and 45 °C. After the modification, the optimal temperature is changed to the range of 50 °C to 55 °C. Other enzymes used for in-gel digestion are the endoproteases Lys-C, Glu-C, Asp-N and Lys-N. These proteases cut specifically at only one amino acid e.g. Asp-N cuts n-terminal of aspartic acid. Therefore, a lower number of longer peptides is obtained.
An international zone is any area not fully subject to the border control policies of the state in which it is located. There are several types of international zones, ranging from special economic zones and sterile zones at ports of entry exempt from customs rules to concessions over which administration is ceded to one or more foreign states. International zones may also maintain distinct visa policies from the rest of the surrounding state.
== Relation to humans == Arapaima is exploited in many ways by local human populations. Its tongue is thought to have medicinal qualities in South America. It is dried and combined with guarana bark, which is grated and mixed into water. Doses are given to kill intestinal worms. The bony tongue is used to scrape cylinders of dried guarana, an ingredient in some beverages, and the bony scales are used as nail files. Arapaima produce boneless steaks and are considered a delicacy. In the Amazon region, locals often salt and dry the meat, rolling it into a cigar-style package that is then tied and can be stored without rotting, which is important in a region with little refrigeration. Arapaima are referred to as the "cod of the Amazon", and can be prepared in the same way as traditional salted cod. Designers have begun using the skin of the arapaima as leather to make jackets, shoes, and handbags, and to cover furniture. In July 2009, villagers around Kenyir Lake in Terengganu, Malaysia, reported sighting A. gigas. The "Kenyir monster", or "dragon fish" as the locals call it, was claimed to be responsible for the mysterious drowning of two men on 17 June. In August 2018, India Times reported that arapaima has been spotted in the Chalakudy River, following floods in Kerala; their presence in India is attributed to illegal importation for fish farming. The arapaima is depicted on both the flag and the seal of the Department of Ucayali, Peru.
== Clinical trials == Sulanemadlin is notable as the first stapled peptide, a novel pharmaceutical strategy, to enter clinical trials. Despite its preclinical promise, concerns about side effects, including severe neutropenia, have terminated Phase 1B clinical trials early in at least one trial.
glycogen A branched polysaccharide composed of as many as 30,000 covalently bonded units of the monosaccharide glucose which functions as the primary form of short-term energy storage in most animal cells. Glycogen reserves are especially abundant in muscle and liver cells, where they can be metabolized at-need into their component glucoses as a means of buffering blood sugar levels, a process known as glycogenolysis.
Sources: en.wikipedia.org
In the opium poppy, the alkaloids are bound to meconic acid. The method is to extract from the crushed plant with diluted sulfuric acid, which is a stronger acid than meconic acid, but not so strong to react with alkaloid molecules. The extraction is performed in multiple steps (one amount of crushed plant is extracted at least six to ten times, so practically every alkaloid goes into the solution). From the solution obtained at the last extraction step, the alkaloids are precipitated by either ammonium hydroxide or sodium carbonate. The last step is purifying and separating morphine from other opium alkaloids. The somewhat similar Gregory process was developed in the United Kingdom during the Second World War, which begins with stewing the entire plant, in most cases save the roots and leaves, in plain or mildly acidified water, then proceeding through steps of concentration, extraction, and purification of alkaloids. Other methods of processing "poppy straw" (i.e., dried pods and stalks) use steam, one or more of several types of alcohol, or other organic solvents. The poppy straw methods predominate in Continental Europe and the British Commonwealth, with the latex method in most common use in India. The latex method can involve either vertical or horizontal slicing of the unripe pods with a two-to five-bladed knife with a guard developed specifically for this purpose to the depth of a fraction of a millimetre and scoring of the pods can be done up to five times.
=== Role in the dental team === Denturists are an important part of the dental team. They often work alongside general dentists, dental specialists and other members of a dental team in both private and public sectors of the oral health workforce. They can also work independently in their own clinic with patients providing appropriate management and treatment of dentures and other oral appliances. Denturists are well educated in clinical and technical knowledge of denture care, as well as completing many hours of practical skills in producing dentures. They ultimately receive more comprehensive study in oral prosthetics than any other health professional including the general dentist since dental schools less emphasis in their curriculum about removable prosthetics and focus on implantology in contrast denturist schools teaches mainstream of removable prosthetics and dentures and spend several years for training. Therefore, the collaborative role of denturists provides an important model of re-allocating dental services to alleviate stresses from the general dentists, reserving time for restorative, cosmetic, hygiene, and emergency dental procedures. Denturists differ from both dental technicians and prosthodontists. Dental technicians are registered members of the dental team who support dental practitioners in the delivery of dental services. Prosthodontists are qualified dentists, who have specialized in making fixed or removable appliances for patients.
== External links == Royal Society of Chemistry, Historical Group, short biography of Curtius University of Kiel history of the inorganic department Heidelberg University German Alpen Association, Kiel section
Since breasts are an external organ and do not contain muscle, exercise cannot improve their shape. They are not protected from external forces and are subject to gravity. Many women mistakenly believe that breasts cannot anatomically support themselves and that wearing a brassiere will prevent their breasts from sagging later in life. Researchers, bra manufacturers, and health professionals have not found any evidence to support the idea that wearing a bra for any amount of time slows breast ptosis. Bra manufacturers are careful to claim that bras only affect the shape of breasts while they are being worn. There is some evidence that bra use reduces the development of Cooper's ligaments, connective tissue that supports breast shape. That atrophy from bra-wearing may therefore lead to more breast sag in the long run, much as the connective tissue in a limb weakens while it is in a cast and must be re-strengthened afterward. Studies have actually documented that, after an initial period of adjustment, women experienced a significant increase in comfort and breast firmness after forgoing bras.
Sources: en.wikipedia.org
This results in adrenal suppression and atrophy and, upon glucocorticoid discontinuation, temporary adrenal insufficiency. Similarly, CPA both in animals and humans can weakly reduce ACTH and cortisol levels and decrease adrenal gland weight as well as cause adrenal insufficiency with discontinuation. These findings suggest that CPA possesses weak glucocorticoid properties. CPA has been reported to be an antagonist of the glucocorticoid receptor (GR) in vitro and may reduce adrenal cortisol and corticosterone production by weakly inhibiting the enzymes 3β-hydroxysteroid dehydrogenase and 21-hydroxylase. These are antiglucocorticoid actions. However, metabolites of CPA, for instance 15β-hydroxycyproterone acetate, may have differing activities. Both cyproterone and CPA have been found to possess glucocorticoid effects, and based on studies in mice, it has been suggested that CPA has approximately one-fifth of the potency of prednisone as a glucocorticoid. The glucocorticoid effects of CPA in humans appear to be less significant than those in animals. Megestrol acetate, medroxyprogesterone acetate, and chlormadinone acetate are all steroidal progestins of the 17α-hydroxyprogesterone family and close analogues of CPA which similarly possess glucocorticoid properties and the potential for producing adrenal insufficiency upon discontinuation.
=== Legal status === CBN is not listed in the schedules set out by the United Nations' Single Convention on Narcotic Drugs from 1961 nor their Convention on Psychotropic Substances from 1971, so the signatory countries to these international drug control treaties are not required by these treaties to control CBN.
Cave 83 (Treasure Cave C) is part of the compact group of the four "Treasure Caves" (82, 83, 84, 85) located at the entrance of the central valley. It is a relatively small square cave (3.6x3.6m), with a podium in the middle, probably for a statue or a stupa. Here the ceiling has collapsed, but probably formed a cupola. The back wall had a well-preserved scene of a Jataka story, the Rudrayana Legend from the Divyavadana, with king Rudrayana observing the dance of his Queen Chandraprabha, who appears nude except for thin veils and jewelry. During the dance, the king had a premonition that his wife would soon die, and she asked to become a Buddhist nun. The style and attitudes of the figures are generally Indian, such as the Tribhanga posture of the dancer, of the way the King is seated. The flutering ribbons of the diadem worn by the king however, were adopted from Iranian royal symbolism. In this cave, the frames of the paintings, especially the vine rinceaux, are probably derived from Roman art of the 1st century CE. This cave may be slightly earlier then Cave 84. The mural was sent to Berlin by Grünwedel (Ref: MIK III 8443). These paintings are soft and delicate: volumes are defined by gradations of shades and colors, not by the sharp limit of a line. Overall, "the brush has the priority over drawing".
=== Pre-discovery use === The use of pitchblende, uranium in its natural oxide form, dates back to at least the year 79 AD, when it was used in the Roman Empire to add a yellow color to ceramic glazes. Yellow glass with 1% uranium oxide was found in a Roman villa on Cape Posillipo in the Gulf of Naples, Italy, by R. T. Gunther of the University of Oxford in 1912. Starting in the late Middle Ages, pitchblende was extracted from the Habsburg silver mines in Joachimsthal, Bohemia (now Jáchymov in the Czech Republic) in the Ore Mountains, and was used as a coloring agent in the local glassmaking industry. In the early 19th century, the world's only known sources of uranium ore were these mines.
Born: Vyacheslav Gryaznov, Russian classical pianist; in Yuzhno-Sakhalinsk, Sakhalin, Russian SFSR, Soviet Union Filip Karadordević, U.S.-born Serbian businessman and heir to the throne of the abolished monarchy of Serbia and Yugoslavia as the eldest son of the former Crown Prince Alexander Karadordević, who was the only child of King Peter II of Yugoslavia; in Vienna, Virginia Died: Red Smith, 76, American sportswriter and columnist, died four days after he had published a column, which he headlined "Writing Less— and Better?" where he announced that he would be writing only three columns per week rather than four.
Sources: en.wikipedia.org
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.
Semax is a synthetic analog of the ACTH(4-10) fragment rather than a copy of the full hormone. Truncation plus the added tail removes the steroidogenic portion of ACTH. That distinction explains why it is studied for nervous-system effects instead of adrenal stimulation.
It is registered as a prescription product in Russia and has been used there clinically, chiefly by the intranasal route. No approval exists in the United States or the European Union. Availability elsewhere typically falls under research-chemical distribution, with varying purity documentation.
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.