If you have been reading about ACTH fragment 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.
Updated 2025-11-11. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White lyophilized powder | Typical for synthetic peptides |
| Solubility | Freely soluble in water | Also soluble in saline |
| Storage temperature | -20 C or below | Protect from repeated freeze-thaw |
| Analytical method | Reverse-phase HPLC | Confirms purity and identity |
| Common synonym | ACTH(4-10) analog | Reflects structural origin |
Common degradation pathways include oxidation of the methionine side chain, hydrolysis of the peptide backbone, and aggregation under unfavourable pH or concentration. Stability studies typically monitor the main peak by chromatography and report total related substances as a percentage. Because no official monograph exists, acceptance criteria vary between laboratories, and reported purity values are not directly comparable across suppliers. Analysts therefore document the method, column, and detection wavelength alongside each result, and open questions remain about how much biological activity the oxidised forms retain.
Solid semax is typically supplied as a lyophilised powder that is hygroscopic and sensitive to moisture, light, and repeated temperature cycling. Long-term storage of the dry peptide is generally recommended at approximately -20 degrees Celsius, while shorter working periods may use refrigeration at 2 to 8 degrees Celsius. Vials should remain tightly closed and desiccated when brought to room temperature, because condensation can damage the material before it is weighed. Dividing a batch into aliquots is preferable to thawing one container repeatedly.
Dissolution is normally performed in water, phosphate-buffered saline, or normal saline, since the peptide is freely soluble in aqueous media and is rarely handled with strong organic solvents. Solution pH should be kept near neutral, because extreme acidity or alkalinity accelerates backbone hydrolysis and encourages oxidation of the methionine side chain. Once dissolved, the material is less stable than the dry powder and is commonly divided into single-use portions and frozen. Buffers containing primary amines, such as Tris, are often avoided because of possible side reactions.
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.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. The first four residues correspond to the ACTH(4-10) fragment, while the terminal Pro-Gly-Pro extension was added to improve metabolic stability. Its molecular formula is C37H51N9O10S and its monoisotopic mass is approximately 813.9 Da. The compound is classified as a peptide research chemical and as a registered pharmaceutical product in Russia, but it does not hold marketing approval in the European Union or the United States. Naming conventions vary across supplier catalogs.
多数实验室与市售的 Semax 以冻干粉形式提供。冻干粉通常建议保存在 -20 °C 或更低温度下，同时避免光照与反复升温。短期运输有时采用冷藏条件，但长期保存仍以冷冻为主。分包操作应尽量减少开盖次数，以降低吸湿和微生物污染的风险。开封后若未一次用完，建议在干燥环境中密封并尽快放回低温储存。
溶液状态的稳定性明显低于冻干粉。肽类在水溶液中可能经历水解、氧化与聚集，其中甲硫氨酸和天冬酰胺等残基常是敏感位点。Semax 含有甲硫氨酸，因此氧化风险相对突出。工作液一般主张现配现用，或冷藏并在数日内用尽。缓冲液种类、pH 和离子强度都会影响降解速率，而关于最佳条件的公开数据并不统一。
常规纯度与身份确认依赖反相高效液相色谱，并辅以质谱测定分子量。氨基酸组成分析可用于验证序列构成，肽图分析则能进一步定位修饰或降解产物。杂质谱通常关注缺失序列肽、截短片段和氧化产物。不同方法的检出限并不相同，因此各实验室报告的纯度数值不宜直接横向比较。
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.
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.
Belize Electricity Limited (BEL), the nation's primary distributor of electricity, proposed a $500 million investment to support the integration of 60 MW of utility-scale solar photovoltaic (PV) generation and 40 MW of battery energy storage systems in its 2024–2028 Full Tariff Review, in an effort to stabilize electricity rates at 40 cents per kilowatt-hour and reduce reliance on imported electricity from Mexico. The Government of Belize's National Energy Policy 2023–2040 commits to achieving 75% renewable energy in the electricity generation mix by 2030. As of 2022, renewable sources accounted for 53% of total gross electricity generation. To improve grid reliability, BEL has initiated several infrastructure upgrades. In 2024, the company completed an upgrade of the West Lake Gas Turbine, increasing its capacity from 19 MW to 30 MW. Additionally, a new gas turbine was installed on Ambergris Caye, adding 20 MW of generation capacity to the national grid. The World Bank is supporting these efforts through the Belize Energy Resilience and Sustainability Project, which includes the deployment of four 10 MW battery storage systems in key districts. Belize Telemedia Limited (BTL), operating under the brand Digi, is the nation's primary telecommunications provider. As of 2025, BTL maintains approximately 32,000 fixed telephone line contracts and serves around 190,000 GSM mobile customers, with active expansion ongoing in accordance with the Government of Belize's National Digital Agenda 2022–2025.
Wrist braces (splints) alleviate symptoms by keeping the wrist straight, which avoids the increased pressure in the carpal tunnel associated with wrist flexion or extension. They are used primarily to help people sleep. Many health professionals suggest that for the best results, one should wear braces at night. When possible, braces can be worn during the activity, primarily causing stress on the wrists. The brace should not generally be used during the day as wrist activity is needed to keep the wrist from becoming stiff and to prevent muscles from weakening.
==== Tandem models ==== Between 1958 and 1973, HVEC manufactured 55 tandem accelerators in four progressively larger models. Each generation opened new experiments with heavier ions, higher energies, and previously inaccessible nuclear reactions. The EN model became the production workhorse. First installed at Chalk River in 1959, it was the first large accelerator to use pure sulfur hexafluoride as insulating gas, which allowed higher voltages in a smaller tank. Its commercial viability depended on two developments: sufficiently intense negative ion sources (developed at Chalk River and Wisconsin) and HVEC's invention of the inclined-field acceleration tube, which solved the voltage breakdown problem that had plagued earlier long tubes. HVEC built 30 EN units for institutions across seven countries. At Chalk River, researchers used the EN to discover quasi-molecular states—transient configurations where colliding nuclei briefly orbit each other before separating. The FN model ("King") extended terminal voltages to 9 megavolts in its "Super FN" variant. The first went to Los Alamos in October 1963. HVEC sold 17 FN units to laboratories including Rutgers, Florida State, Stanford, and national research institutes in France and Romania. The MP model ("Emperor"), a much larger model commissioned by the Atomic Energy Commission in 1962, employed an "open truss" column structure—beams fabricated from alternating steel and glass plates bonded with epoxy—that supported a substantially larger terminal while maintaining electrical insulation.
The photosynthetic amoeboids in the genus Paulinella—P. chromatophora, P. micropora, and marine P. longichromatophora—have the only known independently evolved chloroplast, often called a chromatophore. While all other chloroplasts originate from a single ancient endosymbiotic event, Paulinella independently acquired an endosymbiotic cyanobacterium from the genus Synechococcus around 90 – 140 million years ago. Each Paulinella cell contains one or two sausage-shaped chloroplasts; they were first described in 1894 by German biologist Robert Lauterborn. The chromatophore is highly reduced compared to its free-living cyanobacterial relatives and has limited functions. For example, it has a genome of about 1 million base pairs, one third the size of Synechococcus genomes, and only encodes around 850 proteins. However, this is still much larger than other chloroplast genomes, which are typically around 150,000 base pairs. Chromatophores have also transferred much less of their DNA to the nucleus of their hosts. About 0.3–0.8% of the nuclear DNA in Paulinella is from the chromatophore, compared with 11–14% from the chloroplast in plants. Similar to other chloroplasts, Paulinella provides specific proteins to the chromatophore using a specific targeting sequence. Because chromatophores are much younger compared to the canonical chloroplasts, Paulinella chromatophora is studied to understand how early chloroplasts evolved.
Sources: en.wikipedia.org
==== Pressure on the legal profession ==== A group of 90 lawyers from Hebei, Henan and Shandong—the three worst affected provinces—had made pro bono offers to assist victims, and a list of their names was published. Organisers of the group declared that they had come under pressure from officials to not get involved in the issue. The Beijing Lawyers' Association, a part of the Communist Party apparatus, asked its members "to put faith in the party and government". Other members of the group have reportedly received less subtle requests. Authorities are said to fear social unrest if lawsuits were unleashed. Pro-Beijing Hong Kong journal Ta Kung Pao reported that central authorities, fearful of the effect of mass lawsuits, held a meeting with lawyers' groups on 14 September, asking them to "act together, and help maintain stability". Chang Boyang, one of the group of volunteer lawyers, said he had filed one suit in Guangdong against Sanlu on behalf of the parents of one victim, and another suit in Henan. According to Chang, the justice department of Henan ordered 14 Henan lawyers to drop their cases and "follow the arrangements set out by the government". He said they were told that if they did not, "the lawyer and the firm will be dealt with." Zhang Yuanxin, lawyer and officer in the Xinjiang Lawyers' Association said that these government actions have "set back the development of the legal profession," and called this interference in citizen lawsuits "intolerable".
Two classes of drugs target the mevalonate pathway: statins (like rosuvastatin), which are used to reduce elevated cholesterol levels, and bisphosphonates (like zoledronate), which are used to treat a number of bone-degenerative diseases.
Realizing that he cannot win with brute force, Neo allows Smith to assimilate him, which enables the machines to eradicate the Smith virus directly through his body. Unfortunately, the process also kills Neo. Neo's body is taken away by the machines in the Machine City, while below in Zion, the machines stop their attack and depart in deference to the peace that Neo bartered. The Matrix is rebooted and a beautiful sunrise appears over the horizon, created by Sati in Neo's honor.
Sources: en.wikipedia.org
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.
Peptidases degrade the compound within minutes in circulation. This short half-life is one reason nasal delivery is used, placing the substance close to the olfactory and trigeminal pathways.
No large multicenter trials have been published in English-language journals. The existing human evidence consists mainly of smaller studies conducted in Russia, which limits generalization.
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.