The short version of nootropic fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-12-09 and is reviewed periodically as new material appears.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its design combines the ACTH(4-7) core fragment with a C-terminal Pro-Gly-Pro extension, a modification intended to improve stability and prolong activity. The molecule is hydrophilic, carries no lipid chains or glycosylation, and has a theoretical mass just over 810 daltons in its free form. All seven residues are proteinogenic amino acids, so no non-natural building blocks appear in the backbone. A free N-terminal methionine and C-terminal proline define the unmodified parent peptide.
The compound was developed during the 1980s at the Institute of Molecular Genetics in Moscow as part of research on fragments of adrenocorticotropic hormone. Early work examined short ACTH-derived sequences that retained neurotrophic effects while lacking the endocrine activity of the full hormone. Semax entered clinical use in Russia during the 1990s, where it received registration for several neurological indications. Outside that region it remained primarily a laboratory research material rather than an approved therapeutic. English-language literature on it grew more slowly and frequently cited the original Russian studies.
Pharmacological accounts link semax to melanocortin signalling and to modulation of neurotrophic factor expression, particularly brain-derived neurotrophic factor and nerve growth factor. Much of this evidence comes from rodent studies using intranasal delivery, a route chosen because it allows peptides to reach the central nervous system with limited systemic exposure. Whether the same mechanisms operate in humans at comparable magnitude remains an open question. The precise receptor or receptors responsible for the reported behavioural and neuroprotective effects have not been conclusively identified.
Clinical reports describe use in ischaemic stroke, transient ischaemic attack, optic nerve conditions, and cognitive complaints, but most of these studies are small and were conducted in a single region. Systematic reviews have generally described the evidence base as limited in size and variable in methodological quality. Randomised controlled data suitable for international regulatory assessment are scarce. As a result, major treatment guidelines outside Russia do not include the peptide, and interest in it remains largely research-driven rather than routine clinical.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | ACTH(4-7) analogue |
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Free N terminus, unmodified side chains |
| Molecular weight | 813.9 Da | Free base; salt forms differ |
| Appearance | White to off-white powder | Lyophilised solid |
| Solubility | Freely soluble in water | Hydrophilic; polar solvents preferred |
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.
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.
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.
该化合物于二十世纪八十年代在俄罗斯被开发，相关工作由俄罗斯科学院分子遗传学研究所的研究团队主导。开发目标并非复制 ACTH 的完整激素活性，而是寻找保留其神经作用方向、同时去除促肾上腺皮质激素释放效应的短肽片段。研究记录显示，这一方向促成了多个相关短肽的合成与筛选，而 Semax 是其中被研究最广泛的一个。当地文献常以 Семакс 这一名称指代它。
研究兴趣主要集中在神经营养因子相关的路径上，包括脑源性神经营养因子与神经生长因子的表达变化。部分实验报告称在特定条件下观察到这些因子的水平上升，但具体信号通路和剂量依赖关系仍未完全厘清。多数公开数据来自细胞模型和动物实验，人体对照研究数量有限。因此，该化合物的作用机制在文献中属于活跃讨论，而非已经确立的定论。
Semax 是一种人工合成的七肽，氨基酸序列为 Met-Glu-His-Phe-Pro-Gly-Pro，单字母缩写记作 MEHFPGP。它被归类为促肾上腺皮质激素片段 ACTH(4-10) 的结构类似物，但并不天然存在于生物体内。母体片段 ACTH(4-10) 的序列为 Met-Glu-His-Phe-Arg-Trp-Gly，Semax 替换了中间两个残基，并在羧基端延长了 Pro-Gly-Pro 三肽。这种延长被普遍认为能提升分子对肽酶的耐受性。
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.
In genetics, a strain is said to be auxotrophic if it carries a mutation that renders it unable to synthesize an essential compound. For example, a yeast mutant with an inactivated uracil synthesis pathway gene is a uracil auxotroph (e.g., if the yeast orotidine 5'-phosphate decarboxylase gene is inactivated, the resultant strain is a uracil auxotroph). Such a strain is unable to synthesize uracil and will only be able to grow if uracil can be taken up from the environment. This is the opposite of a uracil prototroph, or in this case a wild-type strain, which can still grow in the absence of uracil. Auxotrophic genetic markers are often used in molecular genetics; they were famously used in Beadle and Tatum's Nobel Prize-winning work on the one gene-one enzyme hypothesis, connecting mutations of genes to protein mutations. This then allows for biosynthetic or biochemical pathway mapping that can help determine which enzyme or enzymes are mutated and dysfunctional in the auxotrophic strains of bacteria being studied. Researchers have used strains of E. coli auxotrophic for specific amino acids to introduce non-natural amino acid analogues into proteins. For instance cells auxotrophic for the amino acid phenylalanine can be grown in media supplemented with an analogue such as para-azido phenylalanine. Many living things, including humans, are auxotrophic for large classes of compounds required for growth and must obtain these compounds through diet (see vitamin, essential nutrient, essential amino acid, essential fatty acid).
=== Protein purification === Polyhistidine-tags are often used for affinity purification of polyhistidine-tagged recombinant proteins expressed in Escherichia coli or other expression systems. Typically, cells are harvested via centrifugation and the resulting cell pellet lysed either by physical means or by means of detergents and enzymes such as lysozyme or any combination of these. At this stage, the lysate contains the recombinant protein among many endogenous proteins originating from the host cells. The lysate is exposed to affinity resin bound to a carrier matrix coupled with a divalent cation, either by direct addition of resin (batch binding) or by passing over a resin bed in a column format. The resin is then washed with buffer to remove proteins that do not specifically interact with bound cation and the protein of interest is eluted off the resin using buffer containing a high concentration of imidazole or a lowered pH. The purity and amount of protein can be assessed by methods such SDS-PAGE and Western blotting. Affinity purification using a polyhistidine-tag usually results in relatively pure protein. Protein purity can be improved by the addition of a low (20-40 mM) concentration of imidazole to the binding and/or wash buffers. However, depending on the requirements of the downstream application, further purification steps using methods such as ion exchange or size exclusion chromatography may be required. IMAC resins typically retain several prominent endogenous proteins as impurities. In E.
Other hormones (stimulating- or releasing -hormones) Plasma concentrations of ions or nutrients, as well as binding globulins Neurons and mental activity Environmental changes, e.g., of light or temperature One special group of hormones is the tropic hormones that stimulate the hormone production of other endocrine glands. For example, thyroid-stimulating hormone (TSH) causes growth and increased activity of another endocrine gland, the thyroid, which increases output of thyroid hormones. To release active hormones quickly into the circulation, hormone biosynthetic cells may produce and store biologically inactive hormones in the form of pre- or prohormones. These can then be quickly converted into their active hormone form in response to a particular stimulus. Eicosanoids are considered to act as local hormones. They are considered to be "local" because they possess specific effects on target cells close to their site of formation. They also have a rapid degradation cycle, making sure they do not reach distant sites within the body. Hormones are also regulated by receptor agonists. Hormones are ligands, which are any kinds of molecules that produce a signal by binding to a receptor site on a protein. Hormone effects can be inhibited, thus regulated, by competing ligands that bind to the same target receptor as the hormone in question. When a competing ligand is bound to the receptor site, the hormone is unable to bind to that site and is unable to elicit a response from the target cell. These competing ligands are called antagonists of the hormone.
=== Psychedelics === Jung's theories are considered to be a useful therapeutic framework for the analysis of unconscious phenomena that become manifest in the acute psychedelic state. This view is based on correspondence Jung had with researchers involved in psychedelic research in the 1950s, as well as more recent neuroimaging research where subjects who are administered psychedelic compounds seem to have archetypal religious experiences of "unity" and "ego dissolution" associated with reduced activity in the default mode network. This research has led to a re-evaluation of Jung's work, particularly the visions detailed in The Red Book, in the context of contemporary psychedelic, evolutionary, and developmental neuroscience. For example, in a chapter entitled "Integrating the Archaic and the Modern: The Red Book, Visual Cognitive Modalities and the Neuroscience of Altered States of Consciousness", in the 2020 volume Jung's Red Book for Our Time: Searching for Soul Under Postmodern Conditions, Volume 4, it is argued Jung was a pioneer who explored uncharted "cognitive domains" that are alien to Western modes of thought. While such domains of experience are not part of mainstream Western culture and thought, they are central to various Indigenous cultures that use psychedelics such as Iboga and Ayahuasca during rituals to alter consciousness. The author writes: "Jung seems to have been dealing with modes of consciousness alien to mainstream Western thought, exploring the terrain of uncharted cognitive domains.
Sources: en.wikipedia.org
==== Australia ==== DET is considered a Schedule 9 prohibited substance in Australia under the Poisons Standard (October 2015). A Schedule 9 substance is a substance which may be abused or misused, the manufacture, possession, sale or use of which should be prohibited by law except when required for medical or scientific research, or for analytical, teaching or training purposes with approval of Commonwealth and/or State or Territory Health Authorities.
Tests in community settings without laboratories, which are disease-specific include tests for Chagas disease, cholera, COVID-19, diabetes mellitus, hepatitis B and C, HIV, influenza, malaria, Streptococcal pharyngitis, sickling disorders, syphilis, tuberculosis, visceral leishmaniasis.
== External links == Signal+Peptide at the U.S. National Library of Medicine Medical Subject Headings (MeSH) SPdb (Signal Peptide DataBase) Archived 2016-01-22 at the Wayback Machine SignalP — predicts the presence and location of signal peptide cleavage sites in amino acid sequences from different organisms.
Hernias usually present as bulges in the groin area that can become more prominent when coughing, straining, or standing up. The bulge commonly disappears on lying down. Mild discomfort can develop over time. The inability to "reduce", or place the bulge back into the abdomen, usually means the hernia is 'incarcerated' which requires emergency surgery.
== Interactions == Concurrent use with inhibitors or inducers of the cytochrome P450 isoenzymes CYP1A2, CYP2D6, or CYP3A4 can result in altered concentrations of mirtazapine, as these are the main enzymes responsible for its metabolism. As examples, fluoxetine and paroxetine, inhibitors of these enzymes, are known to modestly increase mirtazapine levels, while carbamazepine, an inducer, considerably decreases them. Liver impairment and moderate chronic kidney disease have been reported to decrease the oral clearance of mirtazapine by about 30%; severe kidney disease decreases it by 50%. Mirtazapine in combination with a selective serotonin reuptake inhibitor, serotonin–norepinephrine reuptake inhibitor, or tricyclic antidepressant as an augmentation strategy is considered to be relatively safe and is often employed therapeutically but caution should be given when combined with fluvoxamine, which inhibits the isoenzymes normally responsible for metabolic clearing, leading to dramatically increased blood plasma levels of mirtazapine. There is a combination of venlafaxine and mirtazapine, sometimes referred to as "California rocket fuel". Several case reports document serotonin syndrome induced by the combination of mirtazapine with other agents (olanzapine, quetiapine, tramadol and venlafaxine). According to information from the manufacturers, mirtazapine should not be started within two weeks of any monoamine oxidase inhibitor usage; likewise, monoamine oxidase inhibitors should not be administered within two weeks of discontinuing mirtazapine.
Sources: en.wikipedia.org
=== Diet supplement === Donkey's milk is recommended for countering stomach acid, promoting the growth of intestinal flora, calming coughs and pertussis (a.k.a. whooping cough), and for use in the treatment of immune-mediated disorders.
The introduction of nucleophilic catalyst can significantly enhance reaction rate (shown in Figure 7). For example, using aniline as a nucleophilic catalyst, a less populated protonated carbonyl becomes a highly populated protonated Schiff base. In other words, it generates a high concentration of reactive electrophile. The oxime ligation can then occur readily, and it has been reported that the rate increased up to 400 times under mild acidic condition. The key of this catalyst is that it can generate a reactive electrophile without competing with desired product.
is the density of the fluid at all points in the fluid. Bernoulli's equation and the Bernoulli constant are applicable throughout any region of flow where the energy per unit mass is uniform. Because the energy per unit mass of liquid in a well-mixed reservoir is uniform throughout, Bernoulli's equation can be used to analyze the fluid flow everywhere in that reservoir (including pipes or flow fields that the reservoir feeds) except where viscous forces dominate and erode the energy per unit mass. The following assumptions must be met for this Bernoulli equation to apply:
== History == LFTs derive from paper chromatography, which was developed in 1943 by Martin and Synge, and elaborated in 1944 by Consden, Gordon and Martin. There was an explosion of activity in this field after 1945. The ELISA technology was developed in 1971. A set of LFT patents, including the litigated US 6,485,982 described below, were filed by Armkel LLC starting in 1988. The first commercially available lateral flow device was Unipath's Clearblue One Step in 1988. This product combined Paired Monoclonal Antibody technology (patented in 1980 by Unipath's Prof. Philip Porter and colleagues including Paul Davis and Keith May) and the original Clearblue product launched in June 1985.
Other interpretations are also possible, including that the increasing references are the result of more systematic knowledge sharing practices. Maimonides (c. 1135–1204), a renowned philosopher and polymath of the era in both the Jewish and Islamic worlds, claimed to have seen more than 20 cases (in contrast to Galen's two cases). Abd al-Latif al-Baghdadi (1162–1231), also a philosopher and polymath, produced a treatise dedicated to diabetes (On Diabetes, Fols. 140v-149r).
Sources: en.wikipedia.org
It is a synthetic seven-amino-acid peptide built from the ACTH(4-7) sequence plus a Pro-Gly-Pro tail. It belongs to the family of short ACTH fragments studied for nervous-system effects. Its backbone contains only standard amino acids.
It contains the 4-7 fragment of adrenocorticotropic hormone extended at the C terminus. That truncation removes the region associated with steroidogenic activity. The design intent was to keep neurotrophic properties while avoiding full hormonal effects.
No natural source of the intact heptapeptide is known. It is produced by solid-phase peptide synthesis. Some related ACTH fragments arise as hormone processing products, but the Pro-Gly-Pro extension is a designed addition rather than a natural sequence.
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.