A practical reference on MC4 receptor: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-08-14 and is reviewed periodically as new material appears.
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.
Pharmacological accounts link semax to melanocortin signalling and to modulation of neurotrophic factor expression, particularly brain-derived neurotrophic factor and nerve growth factor. Much of this evidence comes from rodent studies using intranasal delivery, a route chosen because it allows peptides to reach the central nervous system with limited systemic exposure. Whether the same mechanisms operate in humans at comparable magnitude remains an open question. The precise receptor or receptors responsible for the reported behavioural and neuroprotective effects have not been conclusively identified.
The mechanisms attributed to semax are inferred from animal and cell studies rather than traced to one confirmed target. The most frequently cited pathway involves increased expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal and cortical tissue. Some work points to engagement of melanocortin receptors, particularly MC4, which the parent ACTH fragment can activate. Effects on dopaminergic and serotonergic signalling have also been reported. No single account explains all observed results, and the relative weight of each pathway remains unsettled.
Published studies examine a fairly narrow set of endpoints. Rodent experiments commonly measure maze learning, infarct volume after induced ischemia, and tissue levels of neurotrophic factors. Clinical reports from Russian centres describe attention, memory and recovery scores in patients after stroke or transient ischemic attack. Most of those human studies are small and few have been repeated by independent groups. Outcome measures differ between studies, which limits direct comparison.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Free acid form of the heptapeptide; depends on terminal groups |
| Molecular mass | About 813.9 g/mol | Average mass used for mass spectrometry confirmation |
| Appearance | White to off-white solid | Supplied as a lyophilised powder; hygroscopic |
| Solubility class | Freely soluble in aqueous media | Water, saline, and phosphate buffers; limited organic solubility |
| Typical storage temperature | -20 degrees Celsius | Long term and dry; short working periods may use 2 to 8 degrees Celsius |
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。
该化合物于二十世纪八十年代在俄罗斯被开发，相关工作由俄罗斯科学院分子遗传学研究所的研究团队主导。开发目标并非复制 ACTH 的完整激素活性，而是寻找保留其神经作用方向、同时去除促肾上腺皮质激素释放效应的短肽片段。研究记录显示，这一方向促成了多个相关短肽的合成与筛选，而 Semax 是其中被研究最广泛的一个。当地文献常以 Семакс 这一名称指代它。
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。
Identity and purity of semax are established with reversed-phase high-performance liquid chromatography coupled to ultraviolet detection, usually at 214 nanometres. Mass spectrometry, most often electrospray ionisation in positive mode, confirms the molecular mass and reveals truncated sequences. Amino acid analysis and peptide mapping after enzymatic digestion provide additional structural confirmation. Laboratories typically report purity as the percentage area of the main peak, a figure that does not capture isomeric or oxidised variants unless the method resolves them.
The peptide is prone to several degradation pathways. Oxidation of the methionine residue produces a sulfoxide that elutes close to the parent peak in many chromatographic systems. Hydrolysis of peptide bonds and deamidation of susceptible residues in related sequences also reduce purity over time. Lyophilised material kept dry at minus twenty degrees Celsius and shielded from light is the most stable form commonly described in laboratory practice.
当时的短肽研究普遍关注能否穿越血脑屏障、在低剂量下产生中枢效应，Semax 属于这一路线。鼻内给药是其主要使用方式，俄语文献报道的适应症涵盖缺血性卒中、短暂性脑缺血发作、认知功能减退以及视神经病变。这些研究大多发表在当地期刊上，样本规模与终点设置同西方试验惯例存在差异，国际同行对其临床证据的强度看法不一。
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。
Nondeletion forms: These defects, in general, involve a single base-pair substitution or small insertions near or upstream of the HBB gene. Deletion forms: base-pair deletions of different sizes involving the HBB gene produce syndromes such as hereditary persistence of fetal hemoglobin syndrome. Mutations are characterized as (βo) if they prevent any formation of β globin chains, and mutations are characterized as (β+) if they allow some β globin chain formation to occur.
Cardiovascular Bradycardia Bundle branch blocks Complete heart block and arrhythmias Cardiomegaly Elevated diastolic blood pressure—early Hypotension—late Low cardiac output Non-specific ECG findings Pericardial effusion Polymorphic ventricular tachycardia (torsades de pointes) Prolonged QT interval Respiratory Hypoxia Hypercapnia Hyperventilation Myxedema of the larynx Pleural effusion Gastrointestinal Abdominal distention Abdominal pain Anasarca Anorexia and nausea Decreased motility Fecal impaction and constipation Gastrointestinal atony or ileus Myxedema or toxic megacolon—late Neurogenic oropharyngeal dysphagia ileus Neurological Altered mentation Coma Confusion and obtundation Delayed tendon reflexes Depression Poor cognitive function Psychosis Seizures Renal and urinary function Bladder dystonia and distension Fluid retention Appearance and dermatological Alopecia Coarse, sparse hair Dry, cool, doughy skin Myxedematous face Generalized swelling Goiter Macroglossia Non-pitting edema Ptosis Periorbital edema Surgical scar from prior thyroidectomy Hypothermia (often marked: usually < 35 °C/ 95 °F) Laboratory features in myxedema coma:
== Proto-Hassuna == This period denotes a higher use of ceramics than with the pre-proto-Hassuna period. The site of Umm Dabaghiyah (de:Umm Dabaghiyah-Sotto-Kultur), in the same area of Iraq, is believed to have the earliest pottery in this region, and is sometimes described as a 'Proto-Hassuna culture' site. Other related sites in the area are Sotto and Yarim Tepe I, having 585 recorded ceramic fragments. They were found by archaeologist A.A. Bobrinsky. Another pre-Hassuna or proto-Hassuna site in Iraq is Tell Maghzaliyah. Yet another site with proto-Hassuna pottery is Ginnig. The time frame for this period was about 6700-6300 BC.
Sources: en.wikipedia.org
== Leadership == Phil Keiser became the second CEO of the franchise in June 2015 until his death in October 2016. Joe Koss followed him in January 2017 until retiring at the end of 2020. He was succeeded by Enrique "Rick" Silva in March 2021. Silva retired in April 2025 and was replaced with Julie Fussner, the first female CEO of the company. She was previously the chief marketing officer, and had been with the company since 2017.
== Economic inequality == In Credit Suisse's Global Wealth Databook 2018, Thailand overtook Russia and India to claim the title of the world's most economically unequal nation. The top 10 percent of Thailand's population as measured by wealth control 85.7 percent of the nation's riches. The bottom 70 percent control five percent. Thailand's Gini coefficient stood at 90.2 (100 = one person owns everything; 0 = total economic equality). Thailand's National Economic and Social Development Board (NESDB) was quick to repudiate the findings, calling them based on old data and faulty estimates. Thailand has been ranked the world's third most unequal nation after Russia and India, with a widening gap between rich and poor according to Oxfam in 2016. Global Wealth Report 2016: Credit Suisse's annual report on worldwide wealth and its distribution reported that Thailand ranked number three of 38 nations (1=most concentrated wealth; 38=least concentrated wealth) in the amount of national wealth owned by the top one percent. In Thailand, 58 percent of the nation's wealth was controlled by one percent of the population. The top 10 percent control almost 80 percent of the nation's wealth. Russia, at 74.5 percent, outdistanced all other nations in inequality. India at 58.4 percent nudged out Thailand for the second spot. Other ASEAN nations in the study were Indonesia at 49.3 percent and Singapore at 33 percent.
== Further reading == Peter Harper; Lois Reynolds; Tilli Tansey, eds. (2010). Clinical Genetics in Britain: Origins and development. Wellcome Witnesses to Contemporary Medicine. History of Modern Biomedicine Research Group. ISBN 978-0-85484-127-1. Wikidata Q29581774.
Sources: en.wikipedia.org
It is described as a synthetic analogue of the ACTH(4–10) fragment, a short segment of adrenocorticotropic hormone. Its sequence differs from that fragment and includes two proline residues, which influence stability and behaviour in solution.
It appears in Russian pharmaceutical listings as a nasal formulation, but it is not an authorised medicine in the United States or the European Union. Outside those markets it is normally encountered as a research chemical rather than a prescription product.
Laboratory and animal work points to melanocortin signalling and changes in neurotrophic factor levels, especially brain-derived neurotrophic factor. The exact receptor targets and the degree to which these findings transfer to humans are still unresolved.
It consists mainly of animal experiments and small clinical reports, with much of the clinical material published in Russian-language journals. Large independent trials are scarce. Separating reliable effects from chance findings is consequently difficult.