Everything below concerns lyophilized powder. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-08-01. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Published studies are dominated by animal models of stroke, ischemia, and cognitive impairment, with a smaller number of human trials conducted in Russia. Many of the human reports are small, single-center, and published in Russian-language journals, which limits independent scrutiny. Outcome measures vary between studies and often rely on clinician-rated scales rather than objective biomarkers. Systematic reviews have noted the methodological weaknesses and called for larger, preregistered trials before firm conclusions can be drawn.
Claims about enhanced focus, memory, or mood in healthy people rest mostly on anecdotal reports and community discussion rather than on controlled data. It remains unclear whether any cognitive benefit observed in patients recovering from brain injury would extend to uninjured users. Dose-response relationships, long-term safety, and interactions with other drugs are not well characterized in the peer-reviewed literature. Questions about optimal route of administration and treatment duration likewise remain open.
Semax binds to melanocortin receptors and is thought to influence neuronal survival and plasticity rather than to act through the adrenal axis. Laboratory work has shown increased expression of brain-derived neurotrophic factor and nerve growth factor in treated tissue. Changes in c-Fos, a marker of neuronal activation, have also been reported. Because the peptide is rapidly degraded by peptidases, its effects are generally attributed to downstream signaling cascades rather than to sustained receptor occupancy.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Contains one methionine sulfur atom |
| Molecular mass | Approximately 814 Da | Consistent with a seven-residue peptide |
| Appearance | White to off-white powder | Typical lyophilized form |
| Solubility | Freely soluble in water | Also soluble in dimethyl sulfoxide |
| Typical storage | -20 °C, desiccated | Limits methionine oxidation |
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.
纯度评估以反相高效液相色谱为主，通过主峰面积百分比给出粗略结果，再配合电喷雾质谱核对分子量。氨基酸分析可验证组成比例，手性色谱或毛细管电泳用于检查残基构型。常见杂质包括缺失序列的短肽、氧化产物与二聚体。由于多数市售品不附带完整检验报告，独立第三方检测常被用来核实标称值。
从分子层面看，Semax 是线性七肽，没有二硫键、糖基或脂链修饰，N 端为游离氨基，C 端为游离羧基。分子含组氨酸与谷氨酸侧链，因此在水和甲醇等极性溶剂中溶解良好，在非极性溶剂中溶解有限。计算分子量约为 814 Da，与其质子化离子的质荷比吻合，可用于质谱确认。
Terminology around the compound varies by source. It appears in catalogues and papers as Semax, as the heptapeptide ACTH(4-7)-Pro-Gly-Pro, and under various alphanumeric laboratory codes used by individual suppliers. These names refer to the same sequence but may imply different salt forms, purity grades, or counter-ions. Peptide databases usually list the free base mass, while product descriptions sometimes report acetate or trifluoroacetate salts with a different formula weight. Because naming conventions for research peptides are not standardised across vendors, checking the declared sequence and measured mass is more reliable than relying on a trade name alone.
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.
genotoxicity The ability of certain chemical agents to cause damage to genetic material within a living cell (e.g. through single- or double-stranded breaks, crosslinking, or point mutations), which may or may not result in a permanent mutation. Though all mutagens are genotoxic, not all genotoxic compounds are mutagenic.
Both morphine and its hydrated form are sparingly soluble in water. For this reason, pharmaceutical companies produce sulfate and hydrochloride salts of the drug, both of which are over 300 times more water-soluble than their parent molecule. Whereas the pH of a saturated morphine hydrate solution is 8.5, the salts are acidic. Since they derive from a strong acid but weak base, they are both at about pH = 5; as a consequence, the morphine salts are mixed with small amounts of NaOH to make them suitable for injection. Many salts of morphine are used, with the most common in current clinical use being the hydrochloride, sulfate, tartrate, and citrate; less commonly methobromide, hydrobromide, hydroiodide, lactate, chloride, and bitartrate and the others listed below. Morphine diacetate (heroin) is not a salt, but rather a further derivative, see above. Morphine meconate is a major form of the alkaloid in the poppy, as is morphine pectinate, nitrate, sulfate, and some others. Like codeine, dihydrocodeine and other (especially older) opiates, morphine has been used as the salicylate salt by some suppliers and can be easily compounded, imparting the therapeutic advantage of both the opioid and the NSAID; multiple barbiturate salts of morphine were also used in the past, as was/is morphine valerate, the salt of the acid being the active principle of valerian. Calcium morphenate is the intermediate in various latex and poppy-straw methods of morphine production, more rarely sodium morphenate takes its place.
=== SOMC LIFE Center === The LIFE Center provides full service fitness and rehabilitation facilities in Scioto County through centers in Portsmouth, Wheelersburg and Lucasville. Additionally, SOMC has hosted events designed to promote fitness and physical activity, such as the ‘Tri For Your LIFE’ sprint triathlon and ‘Run for your LIFE’ 5/10k. In its first year, SOMC's ‘Tri For Your LIFE’ triathlon featured more than 100 competitors.
Failure of safety-critical polymer components can cause serious accidents, such as fire in the case of cracked and degraded polymer fuel lines. Chlorine-induced cracking of acetal resin plumbing joints and polybutylene pipes has caused many serious floods in domestic properties, especially in the US in the 1990s. Traces of chlorine in the water supply attacked polymers present in the plumbing, a problem which occurs faster if any of the parts have been poorly extruded or injection molded. Attack of the acetal joint occurred because of faulty molding, leading to cracking along the threads of the fitting where there is stress concentration.
Sources: en.wikipedia.org
Collective cell migration is studied over many model species. Border cells in flies (Drosophila melanogaster): the border cells migrate during the differentiation of egg cells to be ready for fertilization. The lateral line in zebrafish: collective cell migration from head to tails is essential to the development of the sensory system of the fish. The sensors of the lateral line measure the flow over the body-surface of the fish. Wound healing: collective cell migration is an essential part in this healing process, wound area is closed by the migrating cells. Wound healing is commonly studied in vitro using cell lines such as Madin-Darby Canine Kidney cells. Neural crest cells in mice, Leghorn chicks, amphibians (Xenopus laevis), and fish (zebrafish): collective migration of neural crest cells occurs during embryo development of vertebrates. They migrate long distances from the head (neural tube) to give rise to different tissues. Spreading of cancer (metastasis): common complication of cancer involve formation of new tumors (secondary tumors), as a result of migration of cancer cells from the primary tumor. Similar to collective cell migration in development and wound healing, cancer cells also undergo epithelial to mesenchymal transition (EMT), that reduces cell-cell adhesions and allows cancer spreading. The diagram on the right shows:
==== Isobutyl nitrite toxicity ==== Isobutyl nitrite is one of the compounds used as poppers, an inhalant drug that induces a brief euphoria. Isobutyl nitrite is known to cause methemoglobinemia. Severe methemoglobinemia may be treated with methylene blue.
=== Tandem fusion === The proteins of interest are simply connected end-to-end via fusion of N or C termini between the proteins. This provides a flexible bridge structure allowing enough space between fusion partners to ensure proper folding. However, the N or C termini of the peptide are often crucial components in obtaining the desired folding pattern for the recombinant protein, making simple end-to-end conjoining of domains ineffective in this case. For this reason, a protein linker is often needed to maintain the functionality of the protein domains of interest.
=== Gas chromatography mass spectrometry === Gas chromatography (GC) is the most widely used method in EI-MS for sample insertion. GC can be incorporated for the separation of mixtures of thermally stable and volatile gases which are in perfect match with the electron ionization conditions.
Hours later, White House press secretary Karoline Leavitt said that acquiring Greenland was "a national security priority of the United States", "vital to deter our adversaries in the Arctic region", and added: "The president and his team are discussing a range of options to pursue this important foreign policy goal, and of course, utilizing the US military is always an option at the commander in chief's disposal." Rubio emphasized that any acquisition of Greenland by the US would be negotiated rather than resort to military force, saying Trump's threats were mainly rhetorical and an effort to push Denmark into approving a US-friendly deal. In the following days Trump said the US is "going to do something [there] whether they like it or not", that "We're not going to have Russia or China occupy Greenland. That's what they're going to do if we don't. So we're going to be doing something with Greenland, either the nice way or the more difficult way" and "I would like to make a deal, you know, the easy way. But if we don't do it the easy way, we're going to do it the hard way," that "the fact that they had a boat land there 500 years ago doesn't mean that they own the land. [I'm] sure we had lots of boats go there also." Asked if obtaining Greenland or preserving NATO was his higher priority, he said "it may be a choice."
Sources: en.wikipedia.org
== Further reading == Virtual Textbook of Organic Chemistry Visualizations of the low-temperature crystal structures of alkanes (methane to nonane) Redwood, Boverton (1911). "Paraffin" . Encyclopædia Britannica. Vol. 20 (11th ed.). pp. 752–756.
ago. A more correct treatment would require the use of delay differential equations. Latent period is the transition time between contagion event and disease manifestation. In cases of diseases with varying latent periods, the basic reproduction number can be calculated as the sum of the reproduction numbers for each transition time into the disease. An example of this is tuberculosis (TB). Blower and coauthors calculated from a simple model of TB the following reproduction number:
Corn and sugar cane are C4 plants, whereas the plants used by bees to produce honey, as well as sugar beet, are predominantly C3 plants. Sugars derived from C4 plants alter the isotopic ratio of sugars in honey but do not affect the isotopic ratio of proteins. In unadulterated honey, the carbon isotopic ratios of sugars and proteins are expected to match. Using this method, adulteration levels as low as seven per cent can be detected.
=== Euphemisms === A huge variety of euphemisms and dysphemisms have been invented to describe semen (for a list of terms see: Sexual slang). Slang terms for semen include cum, jism (also shortened to jizz), spunk (primarily British English), spooge, splooge, load, nut, seed, and love juice. The term cum can also refer to an orgasm (when used as a verb rather than as a noun). The term nut originally referred to a testicle, but can be used to refer to both semen and ejaculation.
=== MURI === The Multidisciplinary University Research Initiative (MURI) encompasses dozens of Universities and a few government organizations. Participating universities include UC Berkeley, UC Los Angeles, UC San Diego, Massachusetts Institute of Technology, and Imperial College in London. The sponsors are Office of Naval Research and the Defense Advanced Research Project Agency. MURI supports research that intersects more than one traditional science and engineering discipline to accelerate both research and translation to applications. As of 2009, 69 academic institutions were expected to participate in 41 research efforts.
Sources: en.wikipedia.org
It is registered as a pharmaceutical product in Russia, where it is typically supplied as a nasal solution. In most other countries it is not an approved drug and is traded as a research chemical instead. Approval status depends entirely on the jurisdiction involved.
Most published work uses intranasal administration, matching the route of the registered Russian formulation. Some animal experiments use intravenous or intraperitoneal injection. The route matters because the intact peptide is cleared rapidly from blood, so exposure differs between methods.
A purity value describes the share of the powder accounted for by the target peptide, usually by high-performance liquid chromatography. It does not confirm that the sequence is correct, which requires mass spectrometry or amino acid analysis. Purity and identity are separate checks.
It is associated with the melanocortin receptor family, particularly subtypes found in the central nervous system. This interaction is separate from the adrenal pathway activated by full-length ACTH.