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Semax Peptide Structure And Origin — Reference Sheet

By Editorial Desk · published 2026-05-07 · last reviewed 2026-06-01 · Guide

The short version of Melanocortin receptor fits in a sentence. The long version — which is the one that helps — is below.

Reviewed 2026-06-01. Anything still debated is marked as such rather than presented as settled.

Semax Peptide Structure and Origin

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.

Mechanism and Research

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.

Semax at a glance

PropertyValueNotes
Chemical classSynthetic heptapeptideACTH(4-7) analogue
SequenceMet-Glu-His-Phe-Pro-Gly-ProFree N terminus, unmodified side chains
Molecular weight813.9 DaFree base; salt forms differ
AppearanceWhite to off-white powderLyophilised solid
SolubilityFreely soluble in waterHydrophilic; polar solvents preferred

Chemical Identity and Research Background

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.

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化学性质与分析表征

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。

Semax Background and Chemistry

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.

Semax 的储存、稳定性与分析

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。

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。

Reference notes

==== Executive function and social rejection sensitivity ==== High sensitivity to social rejection is linked to more severe symptoms of BPD, with executive function playing a mediating role. Executive function—encompassing planning, working memory, attentional control, and problem-solving—moderates how rejection sensitivity influences BPD symptoms. Studies demonstrate that individuals with lower executive function exhibit a stronger correlation between rejection sensitivity and BPD symptoms. Conversely, higher executive function may mitigate the impact of rejection sensitivity, potentially offering protection against BPD symptoms.

Plate heat exchangers can cause the desired evaporation at around 45 °C, with short residence times that reduce the risk of thermal damage. This method can produce an extract with 45% solids. Aroma stripping is done prior to concentration, because those compounds run the risk of being lost during evaporation. Spray drying is the final step in creating instant tea, disregarding control points and packaging. It is the preferred method of drying as opposed to freeze-drying because it is cheaper without sacrificing quality. The principle behind spray drying is one similar to that of aroma stripping, where smaller particles have a greater surface to area ratio. By forcing the liquid extract through a nozzle, the solution atomizes, or becomes very fine droplets. These droplets are met with a countercurrent of hot gas, causing them to evaporate and leave only the solids behind. Droplets are generally dried to around 3-5%, as any lower would increase the risk of burning and anything above could possibly reduce shelf life through increased water activity.

==== Headaches ==== Paracetamol is effective for acute migraine: 39% of people experience pain relief within one hour compared with 20% in the control group. The aspirin/paracetamol/caffeine combination also "has strong evidence of effectiveness and can be used as a first-line treatment for migraine". Paracetamol on its own only slightly alleviates episodic tension headache in those who have them frequently. However, the aspirin/paracetamol/caffeine combination is superior to both paracetamol alone and placebo and offers meaningful relief of tension headache: two hours after administering the medication, 29% of those who took the combination were pain-free as compared with 21% on paracetamol and 18% on placebo. The German, Austrian, and Swiss headache societies and the German Society of Neurology recommend this combination as a "highlighted" one for self-medication of tension headache, with paracetamol/caffeine combination being a "remedy of first choice", and paracetamol a "remedy of second choice".

The structure of TEV protease has been solved by X-ray crystallography. It is composed of two β-barrels and a flexible C-terminal tail and displays structural homology to the chymotrypsin superfamily of proteases (PA clan, C4 family by MEROPS classification). Although homologous to cellular serine proteases (such as trypsin, elastase, thrombin etc.), TEV protease uses a cysteine as its catalytic nucleophile (as do many other viral proteases). Covalent catalysis is performed with an Asp-His-Cys triad, split between the two barrels (Asp on β1 and His and Cys on β2). The substrate is held as a β-sheet, forming an antiparallel interaction with the cleft between the barrels and a parallel interaction with the C-terminal tail. The enzyme therefore forms a binding tunnel around the substrate and side chain interactions control specificity.

Sources: en.wikipedia.org

Reference notes

Reorganized in 1893-5 when the Massachusetts legislature was considering closing fraternal benefit orders. A trustee was appointed to wind up the affairs of the order, and the endowment rank was permanently closed. However, a new benefit scheme was created and the order reformed as the Union Fraternal League, another "International Fraternal Alliance" having been founded in another state. Became the Catholic Fraternal League in 1916. Arthur Preuss noted that this was the only time he had found that a secular order had become a religious one. In 1899 it had about 2,000 members in "Ontario and Quebec, in most of New England and Middle, Northwestern and Pacific states." Local groups called "subordinate assemblies" Catholic Knights of America Catholic Knights and Ladies of America Catholic Knights and Ladies of Illinois - Founded in 1884 in Carlyle, Illinois, as the Catholic Knights of Illinois. Always admitted men and women, ages 18–50. Had 2,000 members in 1899. Had 8,500 members in 1965, 13,000 in 1978. Headquarters in Belleville, Illinois. 45 units in Illinois, the only state in which it is licensed to sell insurance. "Supreme legislative body" meets quadrennially. Original purpose is to "offer cheap life insurance without the danger of going into associations or orders forbidden by our Holy Mother Church." Active in promoting Fraternal Week; a Mass is offered every month for the local members; contributes to Catholic Communication Foundation; "Teens Encounter Christ" retreat for high school youth.

The vocalisations of emus mostly consist of various booming and grunting sounds. The booming is created by the inflatable throat pouch; the pitch can be regulated by the bird and depends on the size of the aperture. Most of the booming is done by females; it is part of the courtship ritual, is used to announce the holding of territory and is issued as a threat to rivals. A high-intensity boom is audible 2 kilometres (1.2 mi) away, while a low, more resonant call, produced during the breeding season, may at first attract mates and peaks while the male is incubating the eggs. Most of the grunting is done by males. It is used principally during the breeding season in territorial defence, as a threat to other males, during courtship and while the female is laying. Both sexes sometimes boom or grunt during threat displays or on encountering strange objects. On very hot days, emus pant to maintain their body temperature. Their lungs work as evaporative coolers and, unlike some other species, the resulting low levels of carbon dioxide in the blood do not appear to cause alkalosis. For normal breathing in cooler weather, they have large, multifolded nasal passages. Cool air warms as it passes through into the lungs, extracting heat from the nasal region. On exhalation, the emu's cold nasal turbinates condense moisture back out of the air and absorb it for reuse. As with other ratites, the emu has great homeothermic ability, and can maintain this status from −5 to 45 °C (23 to 113 °F). The thermoneutral zone of emus lies between 10 and 30 °C (50 and 86 °F).

==== NAD ==== Evolutionary conserved protein domain corresponding to oxidoreductase activity. NAD binding catalyzes redox reactions to alter the oxidation state of metal ions, using NADP+ as an electron acceptor.

As a dangerous virus disease that caused deaths around the world, smallpox had effects on human societies and cultures around the world. It may have been used as a form of biological warfare during the colonial era, and a smallpox weapons factory was established by the Soviet Union in 1947. The disease affected many famous historical figures from the ruler of ancient Egypt Ramses V to the Austrian composer Wolfgang Amadeus Mozart and the American president George Washington. Smallpox gods and goddesses have been worshipped in regions including China and India in the hope of warding off or curing the disease.

== History == The first Canadian A&W restaurant opened in Winnipeg, Manitoba, in 1956. It spread across Canada with over 200 locations in the next ten years. The Canadian restaurants were part of the American chain until 1972 when they were sold to Unilever. In 1975, facing competition from the growing Canadian operations of McDonald's, the company launched an advertising campaign starring an orange-clad mascot, The Great Root Bear. The bear and the tuba jingle that accompanied him became a long-running campaign (the tune, entitled "Ba-Dum, Ba-Dum", was released as a single by Attic Records, credited to "Major Ursus", a play on Ursa Major or "great bear"). The famous Canadian composer and B.C. Hall of Fame winner Robert Buckley helped compose the song. The mascot was so successful that he was eventually adopted as the mascot by the American A&W chain as well. The famous tuba jingle was played by famed Vancouver jazz, classical and session trombonist Sharman King. In the early 1980s, the drive-in style of restaurant was phased out. It was replaced with a modern, pastel-coloured fast food outlet which included marginally healthier options. While the chain continued to open some standalone restaurants, A&W also aggressively pursued shopping mall locations, and as a result A&Ws are still commonly found in Canadian malls of various sizes.

Sources: en.wikipedia.org

Frequently asked questions

What is Semax chemically?

It is a synthetic seven-amino-acid peptide built from the ACTH(4-7) sequence plus a Pro-Gly-Pro tail. It belongs to the family of short ACTH fragments studied for nervous-system effects. Its backbone contains only standard amino acids.

How does it relate to ACTH?

It contains the 4-7 fragment of adrenocorticotropic hormone extended at the C terminus. That truncation removes the region associated with steroidogenic activity. The design intent was to keep neurotrophic properties while avoiding full hormonal effects.

Does it occur naturally?

No natural source of the intact heptapeptide is known. It is produced by solid-phase peptide synthesis. Some related ACTH fragments arise as hormone processing products, but the Pro-Gly-Pro extension is a designed addition rather than a natural sequence.

What receptor system does it engage?

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.

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