This is a working overview of Neurotrophic signalling, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-03-21 and is reviewed periodically as new material appears.
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.
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.
各国监管态度分化明显。俄罗斯按处方药管理，部分东欧国家留有使用记录；欧盟与美国未批准其作为药物上市，市面流通品通常标注为研究用化学品。身份差异意味着标示含量、纯度与无菌性缺少统一核查。体育领域还牵涉反兴奋剂名录，跨境携带则受目的地药品法规约束。
Semax 是人工设计的七肽，序列为 Met-Glu-His-Phe-Pro-Gly-Pro，骨架取自促肾上腺皮质激素片段 ACTH(4-10)。它于二十世纪八十年代在苏联的分子遗传学研究机构内合成。设计目标是保留该片段与注意力和记忆相关的活性，同时剔除促皮质激素释放等内分泌作用。此后俄罗斯将其登记为药品并进入临床使用。
| 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 |
Development of the compound took place in the Soviet Union during the 1980s, largely through peptide research groups affiliated with the Shemyakin-Ovchinnikov Institute and Moscow State University. Investigators screened fragments of adrenocorticotropic hormone for activity on the central nervous system while attempting to separate cognitive effects from hormonal ones. The shortened sequence was selected because it retained behavioral activity in animal models without stimulating corticosteroid release. Early publications described the molecule as an ACTH(4-10) analog.
Published research on this peptide originates mainly from Russian laboratories, and the wider international literature is comparatively thin. Studies have used rodent models of stroke, hypoxia, and memory tasks, with a smaller number of human trials reported. Reported outcomes include changes in attention and memory measures, along with effects on neurotrophic factor expression in some experiments. Small sample sizes, inconsistent dosing protocols, and limited independent replication are widely noted limitations, so the strength of the clinical evidence remains an open question.
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.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. It was developed as a fragment analog of adrenocorticotropic hormone, modeled specifically on the ACTH(4-10) region. The first four residues reproduce that fragment, while a Pro-Gly-Pro tripeptide is appended at the C-terminus. Work on the compound originated in Russia, where it entered clinical use as an intranasal preparation. Its sequence places it among short regulatory peptides studied for effects on the central nervous system rather than on the adrenal axis.
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.
The compound was developed in the 1980s at the Institute of Molecular Genetics in Moscow, where it emerged from research on short ACTH fragments and their effects on the central nervous system. Russian pharmaceutical listings describe it as a nootropic and neuroprotective agent, most often formulated as nasal drops. It is not a marketed medicine in the United States or the European Union, and no pharmacopoeial monograph covers it. Consequently, most published clinical experience with the substance originates from a small number of research centres, mainly in Russia and neighbouring countries.
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.
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.
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Innovations in statistical analysis by Ronald Fisher, Frank Yates and others at Rothamsted Experimental Station facilitated rational experimental design and data analysis in botanical research. The discovery and identification of the auxin plant hormones by Kenneth V. Thimann in 1948 enabled the regulation of plant growth by externally applied chemicals. Frederick Campion Steward pioneered techniques of micropropagation and plant tissue culture controlled by plant hormones. The synthetic auxin 2,4-dichlorophenoxyacetic acid or 2,4-D was one of the first commercial synthetic herbicides.
== Medical uses == Cortisone itself is inactive. It must be converted to cortisol by the action of 11β-hydroxysteroid dehydrogenase type 1. This primarily happens in the liver, the main site at which cortisone becomes cortisol after oral or systemic injection, and can thus have a pharmacological effect. After application to the skin or injection into a joint, local cells that express 11β-hydroxysteroid dehydrogenase type 1 instead convert it to active cortisol. A cortisone injection may provide short-term pain relief and may reduce the swelling from inflammation of a joint, tendon, or bursa in, for example, the joints of the knee, elbow and shoulder and into a broken coccyx. Cortisone is used by dermatologists to treat keloids, relieve the symptoms of eczema and atopic dermatitis, and stop the development of sarcoidosis.
Sources: en.wikipedia.org
=== Drug delivery === Solid lipid nanoparticles can function as the basis for oral and parenteral drug delivery systems. SLNs combine the advantages of lipid emulsion and polymeric nanoparticle systems while overcoming the temporal and in vivo stability issues that troubles the conventional as well as polymeric nanoparticles drug delivery approaches. It has been proposed that SLNs have many advantages over other colloidal carriers i.e. incorporation of lipophilic and hydrophilic drugs feasible, no biotoxicity of the carrier, avoidance of organic solvents, possibility of controlled drug release and drug targeting, increased drug stability and no problems with respect to large scale production. Various functions such as molecules for targeting, PEG chains for stealth properties, or thiol groups for adhesion via disulfide bond formation can be immobilized on their surface. A recent study has demonstrated the use of solid lipid nanoparticles as a platform for oral delivery of the nutrient mineral iron, by incorporating the hydrophilic molecule ferrous sulfate (FeSO4) in a lipid matrix composed of stearic acid. Carvedilol-loaded solid lipid nanoparticles were prepared using hot-homogenization technique for oral delivery with compritol and poloxamer 188 as the lipid and surfactant, respectively. Another example of drug delivery using SLN would be oral solid SLN suspended in distilled water, which was synthesized to trap drugs within the SLN structure.
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== Abstracting and indexing == Xenobiotica is abstracted and indexed in Biochemistry and Biophysics Citation Index, BIOSIS, Chemical Abstracts; Current Contents/Life Science, EBSCO, Science Citation Index, PASCAL, SciSearch, Scopus, and Index Medicus/MEDLINE/PubMed.
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Sources: en.wikipedia.org
In total the Apollo programme involved six crewed Moon landings from 1969 to 1972, and a total of twelve astronauts walked on the surface of the Moon. These were Apollo 11, Apollo 12, Apollo 14, Apollo 15, Apollo 16, and Apollo 17.
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Liberation – How is the active pharmaceutical ingredient disintegrated (for solid oral forms (breaking down into smaller particles), dispersed, or dissolved from the medication? Absorption – How is the active pharmaceutical ingredient absorbed (through the skin, the intestine, the oral mucosa)? Distribution – How does the active pharmaceutical ingredient spread through the organism? Metabolism – Is the active pharmaceutical ingredient converted chemically inside the body, and into which substances. Are these active (as well)? Could they be toxic? Excretion – How is the active pharmaceutical ingredient excreted (through the bile, urine, breath, skin)? Drug metabolism is assessed in pharmacokinetics and is important in drug research and prescribing. Pharmacokinetics is the movement of the drug in the body, it is usually described as 'what the body does to the drug' the physico-chemical properties of a drug will affect the rate and extent of absorption, extent of distribution, metabolism and elimination. The drug needs to have the appropriate molecular weight, polarity etc. in order to be absorbed, the fraction of a drug that reaches the systemic circulation is termed bioavailability, this is simply a ratio of the peak plasma drug levels after oral administration and the drug concentration after an IV administration (first pass effect is avoided and therefore no amount drug is lost). A drug must be lipophilic (lipid soluble) in order to pass through biological membranes because biological membranes are made up of a lipid bilayer (phospholipids etc.).
== See also == mRNA, the nucleic acid messenger that serves as the middleman in the Central Dogma of Biology Ribosome, the molecular machine responsible for protein synthesis Translation, the process of peptide synthesis
==== Elimination ==== Gabapentin, pregabalin, Baclofen and phenibut are all eliminated renally in the urine. They all have relatively short elimination half-lives, with reported values of 5.0 to 7.0 hours, 6.3 hours, 2.0 to 5.0 hours and 5.3 hours, respectively. Similarly, the terminal half-life of gabapentin enacarbil IR (as active gabapentin) is short at approximately 4.5 to 6.5 hours. Because of its short elimination half-life, gabapentin must be administered 3 to 4 times per day to maintain therapeutic levels. Similarly, pregabalin has been given 2 to 3 times per day in clinical studies. Phenibut, also, is taken 3 times per day. Conversely, gabapentin enacarbil is taken twice a day and gabapentin XR (brand name Gralise) is taken once a day.
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.
不存在。它是依据 ACTH 的一段序列人工设计的分子，天然蛋白质中找不到与之完全相同的七肽。名称属于研究代号，而非天然物质名。