synthetic heptapeptide raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
Regulatory status varies sharply by country. Semax is registered for medical use in Russia, where it appears in formularies as a nasal solution, and it also holds registration in a small number of neighbouring states. It has no approval from the United States Food and Drug Administration or the European Medicines Agency, and it is not a scheduled controlled substance in most jurisdictions. Elsewhere it circulates mainly as laboratory material, so purity documentation comes from suppliers rather than from a national pharmacopoeia.
Semax is a synthetic peptide created in the Soviet Union during the early 1980s by researchers working in Moscow. It was built from the short adrenocorticotropic hormone fragment known as ACTH(4-10), and the chain was then extended with three additional amino acids. The resulting molecule was named semax and entered clinical use in Russia in 1994. It is generally described as a nootropic and neuroprotective agent rather than as a hormone analogue.
Identity and purity are established with standard peptide methods. Reversed-phase HPLC with ultraviolet detection near 214 nm resolves the parent peak from deletion and truncation byproducts, and reports typically quote a main-peak percentage. Mass spectrometry by electrospray or MALDI-TOF confirms the expected molecular mass, while amino acid analysis or peptide mapping can verify composition when the sequence itself is in question. A certificate of analysis that pairs a chromatogram with a mass spectrum is more informative than a purity figure alone. Counter-ion content and residual solvents are separate specifications and are frequently omitted.
Semax is normally supplied as a lyophilized powder, and that form is the most stable. Suppliers commonly recommend storage at -20 °C in a desiccated container protected from light, with short-term handling at room temperature limited to weighing and transfer. Powder that has absorbed moisture degrades faster, so vials should be warmed to ambient temperature before opening to prevent condensation on the contents. Hygroscopic behavior is typical of short hydrophilic peptides, and humidity control matters more than temperature alone for long-term retention.
Once dissolved, the peptide is considerably less stable than the solid. Aqueous solutions are usually prepared at neutral to slightly acidic pH, filtered, and divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are a common cause of avoidable loss and are best prevented by never refreezing a thawed aliquot. Adsorption to plastic and glass surfaces can lower the measured concentration of dilute solutions, particularly below roughly 0.1 mg/mL. Buffer choice, salt content, and container material all influence how much peptide remains detectable after storage.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Analogue of the ACTH(4-10) fragment |
| Amino acid sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Single-letter form MEHFPGP |
| Molecular formula | C37H51N9O10S | Free peptide, nominal mass near 814 Da |
| First registration | 1994, Russia | Nasal formulation for neurological indications |
| Typical purity grade | 95% or higher by HPLC | Research material; higher grades used as reference standards |
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.
Proposed mechanisms center on neurotrophic signaling rather than on classical melanocortin receptor activation. Rodent experiments have reported shifts in the expression of brain-derived neurotrophic factor and nerve growth factor after administration, together with changes in the associated receptor systems. Several authors argue that the peptide acts largely through its degradation products and their interaction with peptidergic pathways, but this remains a hypothesis rather than a settled finding. No single molecular target has been identified in a way that the field broadly accepts.
Published research covers ischemic stroke, traumatic brain injury, cognitive impairment, optic nerve conditions and attention-related measures. Much of the human evidence comes from small trials conducted in one country, which limits how far the results generalize. Animal models supply the larger share of the data, and effects seen in rodents do not transfer automatically to people. Reviews have noted that methodological reporting is often incomplete, making it difficult to pool results or compare treatment schedules across studies.
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。
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。
== Practical use == Because radiopharmeuticals require special licenses and handling techniques, they are often kept in local centers for medical radioisotope storage, often known as radiopharmacies. A radiopharmacist may dispense them from there, to local centers where they are handled at the practical medicine facility.
Since June 20, 1979, the FDA has received many questions about Good Laboratory Practice (GLP) regulations (21 CFR 58). The responses to these inquiries are stored in the Dockets Management Branch (HFA-305) and shared with the Agency's Bioresearch Monitoring (BIMO) program managers and district offices to ensure consistency. Consequently, the US FDA published the 1981 Questions & Answers - Good Laboratory Practice Regulations document to consolidate and clarify these responses. This Q&A document categorizes responses by specific GLP provisions to make them more useful for both the FDA headquarters and field offices. The FDA has signed a memorandum of understanding (MOU) with Canada, France, Germany, Italy, Japan, The Netherlands, Sweden, and Switzerland to enhance cooperation on good laboratory practice (GLP) for nonclinical laboratory studies supporting product approvals, aiming to facilitate information exchange and inspections for regulatory oversight. Proposed amendments were published in the Federal Register on August 24, 2016, which aimed to require a comprehensive quality system approach known as a GLP Quality System to enhance the current quality system approach for nonclinical laboratory studies. This system would be mandatory for safety and toxicity studies that support or are intended to support applications or submissions for products regulated by the FDA.
A methadone clinic is a medical facility where medications for opioid use disorder (MOUD) are dispensed. Historically and most commonly, these MOUDs are methadone, although buprenorphine is also increasingly prescribed. Medically assisted drug therapy treatment is indicated in patients who are opioid-dependent or have a history of opioid dependence. Methadone is a schedule II (USA) opioid analgesic, that is also prescribed for pain management. It is a long-acting opioid that can delay the opioid withdrawal symptoms that patients experience from taking short-acting opioids, like heroin, and allow time for withdrawal management. In the United States, by law, patients must receive methadone under the supervision of a physician, and dispensed through the Opioid Treatment Program (OTP) certified by the Substance Abuse and Mental Health Services Administration (SAMHSA) and registered with the Drug Enforcement Administration (DEA). The usual process at the clinic is dispensing methadone daily in liquid form, and ingestion is supervised by the physician. Initially, methadone treatment consists of 30mg to 40mg of methadone. Initial doses are followed by increases in the following days until withdrawal symptoms are suppressed. Many patients with opioid use disorder see effective results in symptom management and compliance on 80mg to 120mg of methadone per day. Although there is no set schedule for the gradual increase of dosage, patients typically experience a 5mg to 10mg increase each day for 5-7 days, until they are maintaining a 60mg per day dosage under physician observation.
Due to its relatively short duration, testosterone propionate is now relatively little used and testosterone undecanoate is the preferred testosterone ester for intramuscular use. Testosterone undecanoate and testosterone buciclate can be injected intramuscularly as infrequently as four times per year. High doses of testosterone esters by intramuscular injection have been studied in healthy young men. Levels of testosterone with intramuscular injections of testosterone cypionate were about 700 ng/dL for 100 mg/week, 1100 ng/dL for 250 mg/week, and 2000 ng/dL for 500 mg/week. In another study, testosterone levels with 600 mg/week testosterone enanthate by intramuscular injection were 2,800–3,200 ng/dL. Intramuscular injection of testosterone propionate as an oil solution, aqueous suspension, and emulsion has been compared. Intramuscular injection of testosterone-containing biodegradable microspheres has been studied.
The wavelength, localization technique, laser intensity, and irradiation period are determined based on the individual phototherapeutic agent, as these factors can vary greatly from compound to compound. Topical applications may be through the incorporation of the phototherapeutic agent with a hydrogel that will slowly leech the compound into the wound, allowing for a more controlled production of ROS and/or heat.
Sources: en.wikipedia.org
The unsanitary conditions engendered by the war, severe overcrowding in barracks, wartime propaganda interfering with public health warnings, and migration of so many soldiers around the world helped the outbreak become a pandemic. Ultimately, World War I created a decisive break with the old world order that had emerged after the Napoleonic Wars, which was modified by the mid-19th century's nationalistic revolutions. The results of World War I would be important factors in the development of World War II approximately 20 years later.
Some research has suggested the half-life of clonidine is dose dependent and approximately doubles upon chronic dosing, while other work contradicts this. Following a 0.3 mg oral dose, a small study of five patients by Dollery et al. (1976) found half-lives ranging between 6.3 and 23.4 hours (mean 12.7). A similar N=5 study by Davies et al. (1977) found a narrower range of half-lives, between 6.7 and 13 hours (mean 8.6), while an N=8 study by Keraäen et al. that included younger patients found a somewhat shorter mean half-life of 7.5 hours.
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=== Further synthesis methods === Pyridines can also be prepared via a Mannich reaction. The products are β-aminoketones (Mannich bases). If the hydrochloride of such a base is reacted with an aldehyde and ammonium acetate, a correspondingly substituted pyridine is obtained. In the Bohlmann-Rahtz synthesis, an enamine is first added to an alkynone. A pyridine is then formed by intramolecular condensation reaction and dehydration between the ketone and the amino group. Under suitable conditions, the enamino ester can be generated in situ. For this purpose, the alkynone can be reacted with ammonium acetate, a keto ester, and an acidic catalyst such as acetic acid or zinc bromide.
Sources: en.wikipedia.org
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== Alternatives to the wound healing assay == Using label-free live cell imaging devices based on quantitative phase imaging, it has been shown that cell motility is highly correlated to wound healing and transwell assay results. The advantage of this fully automated approach is that quantification of cell motility does not require specific sample preparation, allowing cell proliferation to be simultaneously quantified as well.
Sources: en.wikipedia.org
Registered medical products are most often 0.1% nasal drops. Research suppliers ship lyophilized powder, usually in milligram quantities, which is dissolved before use. The active peptide is the same in both cases; presentation and excipients differ.
No. The peptide is synthetic, although it is modelled on a fragment of a naturally occurring hormone. ACTH(4-10) is generated when ACTH is cleaved, but the Pro-Gly-Pro extension is not a known endogenous sequence. It is therefore a designed analogue rather than a natural metabolite.
The label reflects reported effects on attention, memory and recovery after neurological injury in regional clinical reports. Those reports are mostly small and have not been widely replicated outside the region. The classification is descriptive and does not imply a single defined mechanism.
Each freeze-thaw cycle can degrade a fraction of the peptide and promote aggregation. Dividing a stock solution into single-use volumes removes repeated cycling as a variable. It also limits the time a thawed solution spends at room temperature.