Semax comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2025-10-12. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
| 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 |
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。
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。
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.
== Signs and symptoms == MELAS is a condition that affects many of the body's systems, particularly the brain and nervous system (encephalo-) and muscles (myopathy). As such, it is commonly referred to as a mitochondrial encephalomyopathy, due to the co-occurrence of these pathologies. In most cases, the signs and symptoms of this disorder appear in childhood following a period of normal development. Children with MELAS often have normal early psychomotor development until the onset of symptoms between 2 and 10 years old. Though less common, infantile onset may occur and may present as failure to thrive, growth retardation and progressive deafness. Onset in older children typically presents as recurrent attacks of a migraine-like headache, anorexia, vomiting, and seizures. Children with MELAS are also frequently found to have short stature. Most people with MELAS have a buildup of lactic acid in their bodies, a condition called lactic acidemia. Increased acidity in the blood can lead to vomiting, abdominal pain, extreme tiredness (fatigue), muscle weakness, loss of bowel control, and difficulty breathing. Less commonly, people with MELAS may experience involuntary muscle spasms (myoclonus), impaired muscle coordination (ataxia), hearing loss, heart and kidney problems, diabetes, epilepsy, and hormonal imbalances. Lactic acidemia also promotes mitochondrial dysfunction, one of the hallmarks of MELAS pathophysiology.
=== Secondhand smoke === Secondhand smoke is a mixture of smoke from the burning end of a cigarette and the smoke exhaled from the lungs of smokers. It is involuntarily inhaled, lingers in the air for hours after cigarettes have been extinguished, and can cause a wide range of adverse health effects, including cancer, respiratory infections, and asthma. Nonsmokers who are exposed to second-hand smoke at home or work increase their heart disease risk by 25–30% and their lung cancer risk by 20–30%. Second-hand smoke has been estimated to cause 38,000 deaths per year, of which 3,400 are deaths from lung cancer in nonsmokers. Sudden infant death syndrome, ear infections, respiratory infections, and asthma attacks can occur in children who are exposed to second-hand smoke. Scientific evidence shows that no level of exposure to second-hand smoke is safe.
Magnetic resonance angiography (MRA) generates pictures of the arteries to evaluate them for stenosis (abnormal narrowing) or aneurysms (vessel wall dilatations, at risk of rupture). MRA is often used to evaluate the arteries of the neck and brain, the thoracic and abdominal aorta, the renal arteries, and the legs (called a "run-off"). A variety of techniques can be used to generate the pictures, such as administration of a paramagnetic contrast agent (gadolinium) or using a technique known as "flow-related enhancement" (e.g., 2D and 3D time-of-flight sequences), where most of the signal on an image is due to blood that recently moved into that plane (see also FLASH MRI). Techniques involving phase accumulation (known as phase contrast angiography) can also be used to generate flow velocity maps easily and accurately. Magnetic resonance venography (MRV) is a similar procedure that is used to image veins. In this method, the tissue is now excited inferiorly, while the signal is gathered in the plane immediately superior to the excitation plane—thus imaging the venous blood that recently moved from the excited plane.
=== The technology === This parameter is one of the most undetectable in the Universe due to the fact that solid matter structures are at low temperatures and emit weak radiation. Their luminosity, which is difficult to observe, also makes it impossible to observe them with telescopes. Likewise, we cannot detect them by their gravitational effects. However their existence can be detected by analyzing wavelengths between 8 and 13 microns, corresponding to surface temperatures of 300 K. A hypothetical Dyson sphere could thus be detected, provided that the observation is made from space. Locally, the significant dip in luminosity that would result from a giant Dyson sphere (or "Fermi bubble") would allow the detection of a Type III civilization. A megastructure like a Dyson sphere could be the result of a technology based on self-replicating probes, as those imagined by von Neumann. A Type III civilization would have the means to disperse a significant number of these spheres throughout the galaxy, which would have the effect of attenuating the light emitted by the galaxy. Kaku also considers this to be the most efficient method of colonizing space. For example, a galaxy 100,000 light years in diameter would be explored in half a million years. Paul Davies has suggested that a civilization could colonize the galaxy by scattering miniature probes, no larger than the palm of a hand, using nanotechnology. This thesis is realistic, he explains, because it is obvious that the technology is becoming increasingly miniaturized and proportionally less expensive.
Sources: en.wikipedia.org
Thus, most einsteinium samples are contaminated, and their intrinsic properties are often deduced by extrapolating back experimental data accumulated over time. Other experimental techniques to circumvent the contamination problem include selective optical excitation of einsteinium ions by a tunable laser, such as in studying its luminescence properties. Magnetic properties have been studied for einsteinium metal, its oxide and fluoride. All three materials showed Curie–Weiss paramagnetic behavior from liquid helium to room temperature. The effective magnetic moments were deduced as 10.4±0.3 μB for Es2O3 and 11.4±0.3 μB for the EsF3, which are the highest values among actinides, and the corresponding Curie temperatures are 53 and 37 K.
== Speech at the Ceremony Marking the 65th Anniversary of the Basic Law, Germany’s Constitution (2014) == On May 23, 2014, the German Parliament Bundestag held a ceremony commemorating the proclamation of the Basic Law on May 23, 1949. Kermani was invited as the keynote speaker. In his speech, he analyzed the language of the Basic Law, comparing its impact to that of the Luther Bible. Kermani discussed the historic progress made in the postwar period and noted that the Basic Law had created a new reality. Kermani praised the Federal Republic of Germany for upholding constitutional norms. He also commended German society for its willingness to bring about integration and its efforts in this regard. He mentioned Willy Brandt several times. Referring to Brandt, Kermani noted, “If I were to name a single day, a single event, a single gesture in postwar German history for which the word ‘dignity’ seems appropriate, (…) it would be Brandt’s kneeling in Warsaw.” Kermani sharply criticized the restriction of the right to asylum through the 1993 amendment to the Basic Law (asylum compromise), which he described as a distortion of Article 16a and a mutilation of the Constitution. Nevertheless, he emphasized the opportunities that the Federal Republic of Germany has offered immigrants. He concluded his speech—on their behalf—with the words Thank you, Germany. Some members of the CDU/CSU parliamentary group criticized the speech as one-sided or biased; Georg Nüßlein (CSU) left the chamber. In the German media, however, the speech was well received and positively discussed.
=== Gas chromatography coupled to mass spectrometry (GC/MS) === Organic molecules are first extracted from rocks using solvents, capitalizing on chemical properties like the polarity of the molecules to dissolve the molecules. Usually, less than one percent of the organic material from a rock is successfully pulled out in this process, leaving behind undissolved material called kerogen. The organic-rich extract is subsequently purified using silica gel column packed chromatography – eluting the extract through the column with targeted solvents pulls out contaminants and remnant undissolved organic material, which will bind to the polar silica moieties. When the sample is then run through a gas chromatography (GC) column, the compounds separate based on their boiling points and interaction with a stationary phase within the column. The temperature ramping of a gas chromatography column can be programmed to obtain optimal separation of the compounds. After the GC, the molecules are ionized and fragmented into smaller, charged molecules. A mass spectrometer then separates the individual compounds based on their mass-to-charge (M/Z) ratio and measures their relative abundance, producing a characteristic mass spectrum. Peaks representing the relative abundance of the compounds are identified as molecules based on their relative retention times, matches to a library of mass spectra with known compound identities, and comparison to standards.
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 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.