If you have been reading about Neurotrophic signalling and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2025-09-21. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Laboratory work points toward modulation of neurotrophic signaling, particularly expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal tissue. Studies also describe effects on monoamine turnover, inflammatory mediators, and oxidative markers. These observations come mainly from animal models and cultured cells, so the causal chain in humans is not firmly established. Whether the reported molecular changes translate into measurable clinical benefit is an open question. Reviews generally present the mechanism as plausible rather than demonstrated.
Clinical evidence consists largely of small trials with modest sample sizes, often without independent replication. Reported endpoints include cognitive scores, recovery after stroke, and visual function, but study designs vary widely and few trials meet contemporary reporting standards. Systematic reviewers have noted a high risk of bias in several of these reports. No large multicenter trial conducted outside Russia has been published. The compound is therefore best described as investigational in most jurisdictions, with its clinical role still unresolved.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Analogue of the ACTH(4-10) fragment |
| Amino acid sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Single-letter form MEHFPGP |
| Molecular formula | C37H51N9O10S | Free peptide, nominal mass near 814 Da |
| First registration | 1994, Russia | Nasal formulation for neurological indications |
| Typical purity grade | 95% or higher by HPLC | Research material; higher grades used as reference standards |
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 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.
Laboratory descriptions of the material are consistent across suppliers. It appears as a white to off-white lyophilized powder that dissolves readily in water and in polar organic solvents such as dimethyl sulfoxide. Aqueous solutions are clear and colorless at low concentrations. Because the peptide contains methionine, oxidation at the sulfur atom is a recognized degradation pathway, and handling notes usually call for protected, desiccated storage. Reported purity for research-grade lots is generally above 95 percent as measured by reversed-phase high-performance liquid chromatography.
The compound is registered in Russia as a pharmaceutical product, most commonly formulated as a nasal solution, and has been used in that setting since the 1990s. Outside that jurisdiction it is generally handled as a research chemical rather than an approved medicine. Regulatory status therefore differs sharply between countries, and material sold internationally may not correspond to the Russian pharmaceutical formulation. Documentation with commercial samples is typically limited to a certificate of analysis covering purity and identity, not clinical status or local legal classification.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It corresponds to the ACTH(4-7) fragment extended at the C-terminus by a Pro-Gly-Pro tripeptide, an addition intended to slow enzymatic breakdown. The molecular formula is C37H51N9O10S and the molecular mass is approximately 814 daltons. In the literature it is often described as an ACTH(4-10) analog, although that label reflects a naming convention as much as a precise structural relationship. The compound was developed in Russia and remains most closely associated with that research tradition.
Typically, people have fewer than 36 repeats in the polyQ region, which results in the normal production and cytoplasmic localization of the huntingtin. However, 36 or more repeats result in the production of a mutant huntingtin (mHTT), which causes degeneration of medium spiny neurons. Regions of the brain have differing amounts and reliance on these types of neurons and are affected accordingly. Generally, the number of CAG repeats is related to how much this process is affected, and accounts for about 60% of the variation of the age of the onset of symptoms. The remaining variation is attributed to the environment and other genes that modify the mechanism of HD. About 36 to 39 repeats result in a reduced-penetrance form of the disease, with a much later onset and slower progression of symptoms. In some cases, the onset may be so late that symptoms are never noticed. With very large repeat counts (more than 60), HD onset can occur below the age of 20, known as juvenile HD. Juvenile HD is typically of the Westphal variant that is characterized by slowness of movement, rigidity, and tremors. This accounts for about 7% of HD carriers.
=== Guidance on interpretation of BPE scores === A myriad of factors, which are patient specific, can affect the BPE scores derived. Hence, dental professionals should use their expertise, knowledge and experience to form a reasonable decision when interpreting BPE scores. The BPE scores should be taken into account alongside other factors when being interpreted. A general guideline is:
Studies show that the EPOC effect exists after both aerobic exercise and anaerobic exercise. In a 1992 Purdue study, results showed that high intensity, anaerobic type exercise resulted in a significantly greater magnitude of EPOC than aerobic exercise of equal work output. For exercise regimens of comparable duration and intensity, aerobic exercise burns more calories during the exercise itself, but the difference is partly offset by the higher increase in caloric expenditure that occurs during the EPOC phase after anaerobic exercise. Anaerobic exercise in the form of high-intensity interval training was also found in one study to result in greater loss of subcutaneous fat, even though the subjects expended fewer than half as many calories during exercise. Whether this result was caused by the EPOC effect has not been established, and the caloric content of the participants' diet was not controlled during this particular study period. Most researchers use a measure of EPOC as a natural part of the quantification or measurement of exercise and recovery energy expenditure; to others this is not deemed necessary. After a single bout or set of weight lifting, Scott et al. found considerable contributions of EPOC to total energy expenditure. In their 2004 survey of the relevant literature, Meirelles and Gomes found: "In summary, EPOC resulting from a single resistance exercise session (i.e., many lifts) does not represent a great impact on energy balance; however, its cumulative effect may be relevant".
Also, during the 1981 tour, veteran session drummer Andy Newmark stepped in briefly for Knudsen, who was then in rehab. And by the end of 1981, even Simmons had left the band. Now with no remaining original members and a "leader" in McDonald who was ready for a solo career, the group elected instead to disband after a rehearsal without Simmons, according to an interview with McDonald for Listen to the Music, the Doobie Brothers' official video history/documentary released in 1989. He went on to say that by that point they could not have gotten further away from the Doobies sound if they had tried. Simmons, already at work on his first solo album, Arcade, rejoined for a 1982 farewell tour on the condition that this truly would be the end of the Doobie Brothers. At their last concert at the Greek Theatre in Berkeley, California, on September 11, 1982, they were joined onstage by founding member Tom Johnston for what was presumed to be the final rendition of his staple, "China Grove". Former members Porter, Hossack and Hartman subsequently took the stage for an extended version of "Listen to the Music". Knudsen sang lead vocals while Johnston, Simmons and McFee traded licks on guitar. The live album Farewell Tour was released in 1983 and the Greek Theatre concert was released in 2011 as Live at the Greek Theatre 1982.
intensive farming methods requires 214 liters (47 imp gal; 57 U.S. gal) of water; using hydroponics, 70 liters (15 imp gal; 18 U.S. gal); and only 20 liters (4.4 imp gal; 5.3 U.S. gal) using aeroponics. Hydroponic cultures lead to highest biomass and protein production compared to other growth substrates, of plants cultivated in the same environmental conditions and supplied with equal amounts of nutrients. Hydroponics is not only used on earth, but has also proven itself in plant production experiments in Earth orbit.
Sources: en.wikipedia.org
=== Sanctions === After the declaration of independence, and indeed for the entire duration of its existence, Rhodesia did not receive official recognition from any state, although it did maintain diplomatic relations with South Africa, which was then under apartheid. South Africa did not recognise Rhodesia to preserve its fragile positions with other nations, but frequently assisted the Rhodesian state. Portugal maintained informal relations until the Carnation Revolution of 1974. The day following the declaration of independence, the United Nations Security Council passed a resolution (S/RES/216) calling upon all states not to accord Rhodesia recognition, and to refrain from any assistance. The Security Council also imposed selective mandatory economic sanctions, which were later made comprehensive. The US, despite voting in favour of the sanctions at the UNSC, violated them to buy chromium ore from Rhodesia. Kenneth Kaunda, president of Zambia, also accused western oil companies of violating the sanctions and selling oil to Rhodesia.
==== MeSH D12.776.210.500.570 – myogenic regulatory factors ==== MeSH D12.776.210.500.570.590 – myod protein MeSH D12.776.210.500.570.595 – myogenic regulatory factor 5 MeSH D12.776.210.500.570.600 – myogenin
Corticosteroids have become some of the most commonly incorporated lightening agents. Long-term usage over large areas of skin may promote percutaneous absorption, which can produce complications such as skin atrophy and fragility, glaucoma, cataracts, edemas, osteoporosis, menstrual irregularities, and growth suppression. A 2000 study performed in Dakar, Senegal, indicated that chronic usage of skin lighteners was a risk factor for hypertension and diabetes. Chemically lightened skin is more highly susceptible to sun damage and dermal infection. Long-term users of skin bleachers can easily develop fungal infections and viral warts. Pregnant users may also experience health complications for both them and their children.
Conversely, if the UK had such a device, the population could be protected. In 1934, along with a movement to establish a scientific committee to examine these new types of weapons, the RAF offered a £1,000 prize to anyone who could demonstrate a working model of a death ray that could kill a sheep at 100 yards; it went unclaimed.
Sources: en.wikipedia.org
Registered medical products are most often 0.1% nasal drops. Research suppliers ship lyophilized powder, usually in milligram quantities, which is dissolved before use. The active peptide is the same in both cases; presentation and excipients differ.
No. The peptide is synthetic, although it is modelled on a fragment of a naturally occurring hormone. ACTH(4-10) is generated when ACTH is cleaved, but the Pro-Gly-Pro extension is not a known endogenous sequence. It is therefore a designed analogue rather than a natural metabolite.
The label reflects reported effects on attention, memory and recovery after neurological injury in regional clinical reports. Those reports are mostly small and have not been widely replicated outside the region. The classification is descriptive and does not imply a single defined mechanism.
Semax is a synthetic seven-amino-acid peptide derived from a fragment of corticotropin. It is used in Russia as a nasal preparation, while elsewhere it is studied as a research compound. It is not approved as a medicine in most countries.