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 2026-02-05 and is reviewed periodically as new material appears.
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.
Verification of a supplied batch generally combines a certificate of analysis with independent testing, because certificates are self-reported documents. A typical package includes a chromatographic trace, a mass spectrum, and a stated water or counter-ion content. Batch-to-batch consistency matters more than a single purity figure when results are compared across experiments. No single mandatory standard governs research-grade peptide release, so laboratories are expected to define their own acceptance criteria. Residual trifluoroacetate from purification is a frequently overlooked counter-ion.
Lyophilized material is chemically stable for extended periods when kept dry, cold, and protected from light. The powder is hygroscopic, so vials should be warmed to room temperature before opening to reduce condensation on the contents. Once dissolved, the peptide is far less stable because peptide bonds are susceptible to hydrolysis and the methionine residue can oxidize. Solutions are typically aliquoted and held at 2-8 °C for short intervals or frozen for longer ones, and repeated freeze-thaw cycles should be avoided.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Calculated for the free peptide |
| Molar mass | 813.9 g/mol | Anhydrous free base |
| Peptide class | Synthetic heptapeptide | ACTH(4-10) analogue |
| Parent fragment | ACTH(4-10) | Adrenocorticotropic hormone segment |
| Developmental origin | Institute of Molecular Genetics, Moscow | Work began in the 1980s |
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 a synthetic peptide created in the Soviet Union during the early 1980s by researchers working in Moscow. It was built from the short adrenocorticotropic hormone fragment known as ACTH(4-10), and the chain was then extended with three additional amino acids. The resulting molecule was named semax and entered clinical use in Russia in 1994. It is generally described as a nootropic and neuroprotective agent rather than as a hormone analogue.
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.
== Further reading == Farris, Glenn J. (1982). "Pine Nuts as an Aboriginal Food Source in California and Nevada: Some Contrasts" (PDF). Journal of Ethnobiology. 2 (2): 114–122. Farris GJ, Blackburn, TC, Anderson K (1993). "Quality Food: The Quest for Pine Nuts in Northern California". Before the Wilderness: Environmental Management by Native Californians. Ballena Press. pp. 229–240.
Sterile alpha and TIR motif containing 1 Is an enzyme that in humans is encoded by the SARM1 gene. It is the most evolutionarily conserved member of the Toll/Interleukin receptor-1 (TIR) family. SARM1's TIR domain has intrinsic NADase enzymatic activity that is highly conserved from archaea, plants, nematode worms, fruit flies, and humans. In mammals, SARM1 is highly expressed in neurons, where it resides in both cell bodies and axons, and can be associated with mitochondria.
tissue culture The growth and maintenance, or "culturing", of multicellular tissues, or of cells harvested from tissues, under carefully controlled conditions in vitro, in the strictest sense by taking a piece of explanted tissue directly from a living plant or animal and maintaining it outside of the body of the source organism. In common usage, the term may also refer to cell culture in general, especially when growing certain cell types which have been harvested from tissues but dispersed from their original tissue-specific organization into a population of more or less independently growing cells.
Carbon nanotubes can be functionalized to attain desired properties for use in a wide variety of applications. The two main methods of carbon nanotube functionalization are covalent and non-covalent modification. Because of their apparent hydrophobic nature, carbon nanotubes tend to agglomerate, hindering their dispersion in solvents or viscous polymer melts. The resulting nanotube bundles or aggregates reduce the mechanical performance of the final composite. The surface of the carbon nanotubes can be modified to reduce the hydrophobicity and improve interfacial adhesion to a bulk polymer. Chemical routes such as covalent functionalization have been studied extensively, which involves the oxidation of CNTs via strong acids (e.g. sulfuric acid, nitric acid, or a mixture of both) in order to bond the carboxylic groups to the surface of the CNTs as the final product or for further modification by esterification or amination. Free radical grafting is a promising technique among covalent functionalization methods, in which alkyl or aryl peroxides, substituted anilines, and diazonium salts are used as the starting agents. Functionalization can improve CNTs characteristically weak dispersibility in many solvents, such as water - a consequence of their strong intermolecular p–p interactions. This can enhance the processing and manipulation of insoluble CNTs, rendering them useful for synthesizing innovative CNT nanofluids with properties that are tunable for a wide range of applications.
== Academic career == After completing his PhD, he worked as a physicist at Bell Laboratories and Columbia University. In 1960, he became a professor of physics at University of California San Diego. Feher died in 2017, aged 93.
Sources: en.wikipedia.org
toluene, ethyl acetate, acetone, ethanol, acetonitrile, chloroform, dichloromethane, etc.) can then be used to determine the acid-base characteristics of the solid using either the Gutmann, or Good-van Oss theory. Other parameters accessible by IGC include: heats of sorption [1], adsorption isotherms, energetic heterogeneity profiles, diffusion coefficients, glass transition temperatures [1], Hildebrand and Hansen solubility parameters, and crosslink densities.
==== LRRK2 gene ==== The LRRK2 gene (PARK8) encodes for the protein leucine-rich repeat kinase 2 (LRRK2/dardarin). Mutations in the LRRK2 gene account for the majority of autosomal-dominant Parkinson's disease cases. These mutations are the most common known cause of familial and sporadic PD, accounting for approximately 5% of individuals with a family history of the disease and 1% of apparently sporadic cases. Many individuals carrying LRRK2 mutations do not develop PD, and estimates of the likelihood of developing PD vary widely with different mutations. LRRK2 is reported to have over 100 genetic coding variants. Of these, only six (G2019S, I2020T, R1441C/G/H, and Y1699C) have been reliably shown to be pathogenic, based on PD family groupings, and three more (I1372V, R1628P, and G2385R) are suspected to be PD genetic risk factors. The occurrence of LRRK2 variants differs based on population and ethnicity. G2019S is found in most countries, with higher frequency in Ashkenazi Jewish and Berber populations. R1628P and G2385R appear in Asian populations. LRRK2 is involved in the protein uptake, movement and clearance activities of the endolysosomal system, which degrades and removes unwanted proteins, preventing toxic build-up. LRRK2 and alpha-synuclein interact. Some LRRK2 mutations have been linked to dysfunctional protein degradation and clearance. For example, G2019S mutations appear to reduce the ability to clear alpha-synuclein, the protein which forms Lewy bodies. G2019S may also be linked to tau pathology.
=== Metastasis === CAF have been found to promote tumour metastasis in numerous ways. Firstly, they may alter gene expression and have been found to upregulate specific genes involved in pro-tumorigenic pathways including heat shock factor 1 (HSF1). They can also interfere with the function of tumour suppressor genes, such as Tumour protein p53, leading to higher rates of cell proliferation due to the loss of control of the cell cycle. Additionally, CAF have the ability to break down proteins in the extracellular matrix and basement membranes leading to disruption to the normal structure allowing cells to move away from their primary region. The group of proteins known as the matrix metalloproteinases are key to this process. CAF also direct the movement of neoplastic cells by using the Rho-dependent signaling pathway to create tracks for these cells in the matrix.
=== UDP-GalNAc synthesis === Human and selected bacterial GALE isoforms bind UDP-GlcNAc, reversibly catalyzing its conversion to UDP-GalNAc. A family of glycosyltransferases known as UDP-N-acetylgalactosamine:polypeptide N-acetylgalactosamine transferases (ppGaNTases) transfers GalNAc from UDP-GalNAc to glycoprotein serine and threonine residues. ppGaNTase-mediated glycosylation regulates protein sorting, ligand signaling, resistance to proteolytic attack, and represents the first committed step in mucin biosynthesis.
Sources: en.wikipedia.org
== Storage condition == Unlike wine, whose character may change in taste over time and storage conditions, tequila does not change much once bottled, even without ideal storage conditions, much like most other distilled spirits such as whiskey, rum, or vodka. The quality characteristics (flavor, aroma, color, etc.) of a tequila are primarily determined during its aging in wood barrels. To maintain the utmost quality though, some conditions should be met: a constant and moderate temperature (60 to 65 °F), protection from direct sunlight, and maintenance of the integrity of the seal of the bottle. Improper storage conditions will have more effect on the taste of aged tequila rather than the un-aged version, due to tannins and other compounds introduced into the spirit from the aging barrel. For instance, if stored in improper conditions, the dark and more complex flavors of the añejo tequila are more likely to be tainted than the blanco or the silver tequila. Once the bottle is opened, the tequila will be subject to oxidation that will continue to happen even if no more oxygen is introduced. In addition, if the bottle has more room for air, the process of oxidation occurs faster on the liquor remaining inside the bottle. Therefore, it may be the best to consume the tequila within one or two years after opening. For the most part, the change in quality of tequila is due to extreme conditions of improper storage, not due to oxidation.
Progesterone is available for vaginal administration in the form of capsules (Utrogestan), gels (Crinone, Prochieve), suppositories (Cyclogest), inserts/tablets (Endometrin, Lutinus), and rings (Fertiring, Progering). In addition, oral micronized progesterone capsules have been administered vaginally with success. The bioavailability of vaginal micronized progesterone insert is about 4 to 8%. Vaginal absorption of progesterone is lower in postmenopausal women with vaginal atrophy. Following administration of a single 25, 50, or 100 mg vaginal progesterone suppository in women, maximal circulating levels of progesterone occurred within 2 to 3 hours and were 7.27 ± 2.8 ng/mL, 8.84 ± 3.14 ng/mL, and 9.82 ± 9.8 ng/mL, respectively. After peak levels, progesterone levels decreased gradually, with an elimination half-life of 6 to 12 hours. Progesterone levels were less than 3 ng/mL for all three doses after 24 hours. The researchers concluded that the 25 and 50 mg doses would be appropriate for administration three times per day while the 100 mg dose would be appropriate for administration twice per day. The bioavailability of vaginal progesterone gel is about 40-fold greater than that of oral progesterone. Gel bioavailability does not seem to vary between the "Crinone 8%" formulation and two experimental generic formulations of different strengths, peaking at about 10 ng/mL after 90 mg of gel within 7 hours (with a large standard deviation).
In organic chemistry, a carboxylic acid is a polar, organic acid that contains a carboxyl group (−C(=O)−OH) attached to an R-group. The general formula of a carboxylic acid is often written as R−COOH or R−CO2H, sometimes as R−C(O)OH, with R referring to an organyl group (e.g., alkyl, alkenyl, aryl), or hydrogen, or other groups. Carboxylic acids occur widely. Important examples include the amino acids and fatty acids. Deprotonation of a carboxylic acid gives a carboxylate anion. Carboxylic acids are often considered weak acids as they only partially ionise (dissociate) in water.
== CDAs in NMR spectroscopy == CDAs are used with NMR spectroscopic analysis to determine enantiomeric excess and the absolute configuration of a substrate. Chiral discriminating agents are sometimes difficult to distinguish from chiral solvating agents (CSA) and some agents can be used as both. The speed of the exchange between the substrate and the metal center is the most important determining factor to differentiate between the use of a compound as a CDA or CSA. Generally, a CDA has a slow exchange whereas a CSA has a fast exchange. CDAs are more widely used than CSAs to determine absolute configurations because the covalent bonding to the substrate and auxiliary reagent produce species with greater conformational rigidity which creates greater differences in the NMR spectra. CDAs and CSAs can be used together to improve chiral recognition, although this is not a common. NMR shift reagents such as EuFOD, Pirkle's alcohol, and TRISPHAT take advantage of the formation of diastereomeric complexes between the shift reagent and the analytical sample.
The LAL test is a major source of animal product dependence in the biomedical industry, and a challenge to the Three Rs of science in relation to the use of animals in testing. With reports of higher-than anticipated mortality rates it has been considered more ethical to devise alternatives to the test. Since 2003, a recombinant protein substitute for use in the LAL test has been commercially available. Named the recombinant factor C (rFC) assay, it is based on the same Limulus clotting factor C protein, but produced by genetically modified insect cells (the specific factor C sequence used does not necessarily come from the Atlantic horseshoe crab). Instead of emulating the whole clotting pathway, rFC tests let factor C cleave a synthetic fluorogenic substrate, so that the sample lights up when endotoxin activates the factor. Since it does not contain factor G, (1,3)-β-D-glucan will not cause false-positives. As of 2018, available evidence shows that the rFC test is no worse than the LAL test. The adoption of the rFC test was slow, which began to change in 2012 when the US FDA and the European health ministry acknowledged it as an accepted alternative. Its lack of mention in Pharmacopeias remained an issue, as there was no good standard for running the test in production. In 2016, it was added to the European Pharmacopoeia. A patent on rFC also limited adoption until its expiration in 2018.
Sources: en.wikipedia.org
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.
It is registered for clinical use in Russia and a few other countries, typically as a nasal drop formulation. It does not hold approval from the United States Food and Drug Administration or the European Medicines Agency. Outside those markets it is generally handled as a research chemical.
The compound was developed in Moscow and the earliest studies were conducted there, so the primary literature is largely in Russian-language journals. Translation and indexing have been incomplete, which limits access for outside researchers. Independent groups have since published some work, but the total volume remains modest.
Dry powder is normally held at -20 °C or lower, away from light and moisture. Sealed vials can also be kept at 2-8 °C for shorter intervals. Warming to room temperature before opening prevents condensation.