The short version of Semax fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-07-29 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.
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。
| 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 |
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.
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.
=== Regulatory status === Selegiline is a prescription drug. It is not specifically a controlled substance in the United States and hence is not an illegal drug. However, deprenyl and selegiline are controlled substances in Japan. They are classified as "Stimulants", alongside a variety of other amphetamines, under Article 2 of Japan's Narcotics and Psychotropics Control Law. Selegiline is known to metabolize into small amounts of levoamphetamine and levomethamphetamine but is thought to have little to no misuse potential or dependence liability.
A higher value for pKaH corresponds to a stronger base. For example, the values pKaH (C5H5N) = 5.25 and pKaH ((CH3CH2)3N) = 10.75 indicate that (CH3CH2)3N (triethylamine) is a stronger base than C5H5N (pyridine).
Alice in Chains – production Dave Jerden – production (except on "Would?"), mixing Rick Parashar – production on "Would?" Bryan Carlstrom – engineering Annette Cisneros – engineering, mixing Ulrich Wild – engineering Steve Hall – mastering Eddy Schreyer – mastering Mary Maurer – art direction, visual effects Doug Erb – cover design David Coleman – logo Rocky Schenck – photography
=== Contraindications === The use of levosimendan is contraindicated in patients with moderate-to-severe kidney impairment, severe liver impairment, severe ventricular filling or outflow obstruction, very low blood pressure and fast heart rate, and/or history of the abnormal heart rhythm torsades de pointes.
Coevolution between parasite and host can lead to hosts becoming resistant to the parasites or the parasites may evolve greater virulence, leading to immunopathological disease. Human activity is involved with many emerging infectious diseases, such as environmental change enabling a parasite to occupy new niches. When that happens, a pathogen that had been confined to a remote habitat has a wider distribution and possibly a new host organism. Parasites jumping from nonhuman to human hosts are known as zoonoses. Under disease invasion, when a parasite invades a new host species, it may become pathogenic in the new host. Several human activities have led to the emergence of zoonotic human pathogens, including viruses, bacteria, protozoa, and rickettsia, and spread of vector-borne diseases, see also globalization and disease and wildlife disease:
Sources: en.wikipedia.org
=== Conversion to imines === Imine formation is an important reaction. Primary amines react with ketones and aldehydes to form imines. In the case of formaldehyde (R' = H), these products typically exist as cyclic trimers:
The city of Johannesburg sprang up nearly overnight as a shanty town. Uitlanders (foreigners, white outsiders) poured in and settled around the mines. The influx was so rapid that uitlanders quickly outnumbered the Boers in Johannesburg and along the Rand, although they remained a minority in the Transvaal. The Boers, nervous and resentful of the uitlanders' growing presence, sought to contain their influence through requiring lengthy residential qualifying periods before voting rights could be obtained; by imposing taxes on the gold industry; and introducing controls through licensing, tariffs and administrative requirements. Among the issues giving rise to tension between the Transvaal government on the one hand and the uitlanders and British interests on the other, were:
=== Laboratory values === The serum creatine phosphokinase (CPK) can be mildly elevated. While the CPK is often a good marker for damage to muscle tissue, it is not a helpful marker in CIP/CIM, because CIP/CIM is a gradual process and does not usually involve significant muscle cell death (necrosis). Also, even if necrosis is present, it may be brief and is therefore easily missed. If a lumbar puncture (spinal tap) is performed, the protein level in the cerebral spinal fluid would be normal.
=== In humans === Although generally considered safe to use, it is neurotoxic to humans in high doses. Pyrethroids like deltamethrin can also be an allergen that provokes asthma in some people. Deltamethrin temporarily attacks the nervous system of any animal with which it comes into contact. Skin contact can lead to tingling or reddening of the skin local to the application. If taken in through the eyes or mouth, the most common symptom is facial paraesthesia, which can feel like many different abnormal sensations, including burning, partial numbness, "pins and needles", skin crawling, etc. There is one case report describing chronic intoxication from pyrethroid insecticides leading to a syndrome clinically similar to motor neuron disease. There are no antidotes, and treatment must be symptomatic, as approved by a physician. Over time, deltamethrin is metabolized, with a rapid loss of toxicity, and passed from the body. A poison control center should be contacted in the event of an accidental poisoning. Deltamethrin is able to pass from a woman's skin through her blood and into her breast milk, although breastfeeding remains safe under prevailing conditions. In South Africa, residues of deltamethrin were found in breast milk, together with DDT, in an area that used DDT treatment for malaria control, as well as pyrethroids in small-scale agriculture. A 2015 study conducted in Brittany, France, found a negative correlation between deltamethrin exposure (measured through the presence of a metabolite in urine) and cognitive scores in infants.
Sources: en.wikipedia.org
== Early years == Nickson is the daughter of a British father and a Chinese mother. After her father's death in an automobile accident when she was six, Nickson and her mother had to live in a house with three other families. Her grandmother often watched Chinese operas on television, and that kindled Nickson's interest in performing. When she was 17, Nickson left Singapore to study at the University of Hawaiʻi. Her successful audition for a play while she was there led to a shift in interest from business administration to drama. After two years, she left the university to work as a model, study acting, and perform in community theater productions.
=== Aging and life extension === Metformin is under investigation that it may be an agent that delays aging; it may increase longevity in some animal models (e.g., C. elegans and crickets). This effect may be mediated by insulin and carbohydrate regulation, similar to its effects on diabetes. Whether metformin may help extend life, even in otherwise healthy people, remains unknown; a 2021 review of the literature found it is likely to improve healthspan, i.e., the number of years spent in good health, rather than lifespan overall. A 2017 review found that people with diabetes who were taking metformin had lower all-cause mortality. They also had reduced cancer and cardiovascular disease compared with those on other therapies. In people without diabetes, metformin does not appear to reduce the risk of cancer and cardiovascular disease.
A variety of biological activities have been discovered from isolated sv-LAAOs including cytotoxic, antibacterial, antiviral, and antiparasitic activities as well as platelet aggregation effects. These activities can be defined by the enzyme's ability to provoke oxidative stress by forming oxygen radicals and hydrogen peroxide. The particular mechanism of action of sv-LAAOs in terms of platelet aggregation has been determined less clear, because some sv-LAAOs are known to create aggregates and some are known to be anti-aggregating factors. Recent work has shown that LAAO binds directly to the surface of bacterial and mammalian cancer cells, concentrating hydrogen peroxide production at the cell membrane interface. This localized accumulation leads to enhanced oxidative damage, supporting a dual mechanism involving both catalytic activity and membrane interaction. In recent studies, it has been shown that LAAOs have been isolated from the skin and/or gill mucous secretions of rockfish, great sculpin, and flounder. The presence of these enzymes were identified to be a unique type of antibacterial protein in the external defense employed by certain fish species.
where e, f, g and h are the tangent lengths at A, B, C and D respectively. Combining the first equality with a previous property, the "vertex centroid" of the tangential quadrilateral coincides with the incenter if and only if the incenter is the midpoint of the line segment connecting the midpoints of the diagonals. If a four-bar linkage is made in the form of a tangential quadrilateral, then it will remain tangential no matter how the linkage is flexed, provided the quadrilateral remains convex. (Thus, for example, if a square is deformed into a rhombus it remains tangential, though to a smaller incircle). If one side is held in a fixed position, then as the quadrilateral is flexed, the incenter traces out a circle of radius
Alkylglycerone phosphate synthase (EC 2.5.1.26, alkyldihydroxyacetonephosphate synthase, alkyldihydroxyacetone phosphate synthetase, alkyl DHAP synthetase, alkyl-DHAP, dihydroxyacetone-phosphate acyltransferase, DHAP-AT) is an enzyme associated with Type 3 Rhizomelic chondrodysplasia punctata. This enzyme catalyses the following chemical reaction
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.
不是。Semax 是完全人工合成的七肽，自然界中没有对应的已知肽段。它的设计灵感来自促肾上腺皮质激素片段 ACTH(4-10)，但序列经过了替换和延长。