ACTH fragment is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2026-02-25. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
Identity and purity are confirmed with reversed-phase high-performance liquid chromatography, typically monitored at 214 nanometres where the peptide bond absorbs. Mass spectrometry, either electrospray or MALDI-TOF, verifies molecular mass against the theoretical value and detects truncation or adduct formation. Amino acid analysis and peptide mapping provide additional confirmation when required. The most frequently reported impurities are deletion sequences from incomplete coupling, methionine sulfoxide from oxidation, and dimeric species formed through non-covalent aggregation. Impurity profiles depend strongly on the synthesis and purification route chosen by the producer.
Published research has focused mainly on neurological and cognitive endpoints in animal models, with proposed mechanisms involving brain-derived neurotrophic factor and related signalling pathways. A substantial share of the human data originates from a limited number of research groups, and independent replication in other countries remains sparse. Regulatory status reflects that distribution: the peptide is registered as a medicine in Russia and appears in some neighbouring markets, while elsewhere it is handled as a research chemical without approved therapeutic labelling. Questions about dose-response relationships, long-term effects, and comparability across studies are still open.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Seven-residue peptide |
| Molecular mass | 813.9 Da | Monoisotopic value |
| Appearance | White to off-white powder | Lyophilized form |
| Solubility | Freely soluble in water | Also soluble in saline and polar solvents |
| Storage (dry) | -20 °C or lower | Desiccated, protected from light |
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。
稳定性主要由水解与氧化两条路径支配。肽键在中性或弱酸性条件下相对稳定，遇到强碱或长时间高温则明显断裂；甲硫氨酸侧链容易被氧化成亚砜，使主峰前移并拉低实际含量。金属离子、光照和反复冻融会进一步促进降解或聚集。冻干粉在低温避光条件下可存放较长时间，配制后的水溶液通常需要冷藏并尽快用完。
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。
None of them ever denied the charges that they were Freemasons, and when asked, readily stated the positions that they held. However, even in captivity they were able to raise $1,632 to repair the chapel of the Catholic Church. The Parish Priest and the prison doctor then successfully petitioned the Spanish to release those Freemasons from prison.
=== 2011–2022 === KBL-BML-Unilabo Laboratory ("KBL"), based in Antwerp and the Woestyn Laboratory, based in Mouscron, January 2011 Physicians' Automated Laboratory ("PAL"), based in Bakersfield, California, US, January 2011 The laboratory business of Central Coast Pathology Consultants ("CCPC"), a high quality laboratory in California, US, February 2011 In June 2015, Sonic acquired Medisupport, based in Switzerland. In the same month, Sonic acquired KLD Laboratory, based in Belgium. In 2011, Sonic acquired the Woestyn Laboratory (Belgium), cytopathology business Labor Dr. Steinberg (Germany), Central Coast Pathology (San Luis Obispo, California), and Allied Medical and Australian Skin Cancer medical centre groups. In 2012, the company acquired Labor Oldenburg Dr. Müller (Germany) and the Western Australian pathology operations of Healthscope. In 2013, IPN acquired the Australian Locum Medical Service group and Sonic acquired Labco S.A. Group (Germany). In 2014, Sonic acquired San Pathology (Sydney). In 2015, Sonic acquired Medisupport S.A (Switzerland) and Klinisch Laboratorium Declerck (Ardooie, Belgium). In Australia, the company acquired Adelaide Pathology Partners and the Medibank Workplace Health (WPH) and Travel Doctor businesses. In 2016–2017, Sonic acquired 80% ownership of GLP systems (Hamburg, Germany). It acquired Staber Laboratory group (Munich, Germany), Medical Laboratory Bremen, and West Pacific Medical Laboratory (Los Angeles, California).
== Interactions == Octreotide can reduce the intestinal reabsorption of ciclosporin, possibly making it necessary to increase the dose. People with diabetes mellitus might need less insulin or oral antidiabetics when treated with octreotide, as it inhibits glucagon secretion more strongly and for a longer time span than insulin secretion. The bioavailability of bromocriptine is increased; besides being an antiparkinsonian, bromocriptine is also used for the treatment of acromegaly.
== Toxicity == Toxic effects of retinoids occur with both acute and prolonged intake, depending on which retinoid is considered. The specific toxicity is related to the mechanism of action as well as exposure. A medical sign of chronic or acute poisoning with retinol is hypervitaminosis A, which includes the presence of painful, tender swellings on the long bones. Anorexia, skin lesions, hair loss, hepatosplenomegaly, papilloedema, bleeding, general malaise, pseudotumor cerebri, and death may also occur. Retinoids provoke rapid elevation of circulating triglycerides leading to hypertriglyceridemia as well as cholesterol, leading to hypercholesterolemia. Retinoids are further shown to worsen many metabolic diseases, such as diabetes and congestive heart failure. Large-scale randomized, controlled clinical trials have conclusively shown that vitamin A, retinol, and other retinoids increase mortality and cancer rates in smokers and asbestos workers. In addition to the harmful effects shared by other retinoids, bexarotene causes severe hypothyroidism. The Pharmacovigilance Risk Assessment Committee (PRAC), based on its review, confirmed that taking oral retinoids during pregnancy can have harmful effects on the baby as they may cause CNS, cranio-facial, cardiovascular and other defects. The use of acitretin, alitretinoin and isotretinoin should be prohibited in women of childbearing age unless they take measures to prevent pregnancy. Many lotions that claim to prevent or treat stretch marks contain retinol, which is not an ingredient that is safe for pregnant women.
Sources: en.wikipedia.org
Regarding the last quarter-century of the period outlined by Taylor, his American colleague, diplomatic historian Edward Mead Earle, argued: "During the quarter-century beginning about 1890, Europe and the Far East lived under a precarious balance of power with the result … that the world moved crazily from one crisis to another and finally to catastrophe". Earle concludes: "The balance of power may well land us all in crematory". The balance of power theory prepared catastrophe in 1939 as in 1914, wrote Clarence Streit in his famous Union Now. There is "no more sterile, illusory, fantastic, exploded and explosive peace policy than the balance of power." In 1953, Ernst B. Haas criticized balance of power theory, arguing that international relations works that used the concept were plagued with "philological, semantic, and theoretical confusion." Since 1945, the arguments of Streit and Earle has prevailed over that of Taylor. Atomic scientists launched an all-out attack on the balance-of-power concept:
== Biochemical context == Most are accompanied by α-ketoglutarate α-decarboxylation caused by dehydrogenation of hydroxyl carboxylic acids such as carbonyl carboxylic malic acid, isocitric acid, etc. Pyruvate is susceptible to oxidative decarboxylation to deliver the equivalent of the acetyl anion:
Elevated concentrations of 210Po in tobacco were documented as early as 1964, and cigarette smokers were thus found to be exposed to considerably greater doses of radiation from 210Po and its parent 210Pb. Heavy smokers may be exposed to the same amount of radiation (estimates vary from 100 µSv to 160 mSv per year) as individuals in Poland were from Chernobyl fallout traveling from Ukraine. As a result, 210Po is most dangerous when inhaled from cigarette smoke.
=== Overdose === The most common symptoms following an overdose include vomiting, diarrhea, abdominal pain, tachycardia, drowsiness, and rarely, hypoglycemia or hyperglycemia. Treatment of metformin overdose is generally supportive, as no specific antidote is known. Extracorporeal treatments are recommended in severe overdoses. Due to metformin's low molecular weight and lack of plasma protein binding, these techniques have the benefit of removing metformin from the blood plasma, preventing further lactate overproduction. Metformin may be quantified in blood, plasma, or serum to monitor therapy, confirm a diagnosis of poisoning, or assist in a forensic death investigation. Blood or plasma metformin concentrations are usually in a range of 1–4 mg/L in persons receiving therapeutic doses, 40–120 mg/L in victims of acute overdosage, and 80–200 mg/L in fatalities. Chromatographic techniques are commonly employed. The risk of metformin-associated lactic acidosis is also increased by a massive overdose of metformin, although even quite large doses are often not fatal.
Pantothenic acid is a water-soluble vitamin, one of the B vitamins. It is synthesized from the amino acid β-alanine and pantoic acid (see biosynthesis and structure of coenzyme A figures). Unlike vitamin E or vitamin K, which occurs in several chemically related forms known as vitamers, pantothenic acid is only one chemical compound. It is a starting compound in the synthesis of coenzyme A (CoA), a cofactor for many enzyme processes.
Sources: en.wikipedia.org
It is a synthetic peptide of seven amino acids. Its backbone corresponds to a fragment of adrenocorticotropic hormone extended at the carboxyl end. The material is distributed as a lyophilized solid for laboratory use.
The extension was introduced to slow enzymatic breakdown of the peptide in biological systems. Natural ACTH fragments are degraded rapidly by peptidases. Adding the tripeptide was intended to extend the window during which the molecule remains intact.
Most published work consists of animal experiments conducted in a small number of laboratories. Human data are limited in number and size. Whether the observed effects translate into reliable clinical benefit is still unresolved.
Reversed-phase HPLC gives the main purity figure, most often with UV detection near 214 nanometres. Mass spectrometry then confirms the molecular mass. Together the two methods distinguish a correct sequence from a closely related impurity.