If you have been reading about lyophilized powder and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-08-01. Where a claim depends on a specific study, the study is described rather than over-claimed.
Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead as a research chemical.
Later generations of the molecule include an N-acetylated form and an amidated form, both marketed online alongside the parent peptide. These variants differ in terminal chemistry and stability, and they are frequently discussed in the same breath even though they have not been compared in controlled trials. Supply outside formal healthcare systems comes largely from laboratories that synthesize peptides to order. Purity and identity of these materials vary widely, and no single body oversees the international trade.
Semax is a synthetic heptapeptide developed in the Soviet Union during the 1980s by researchers at the Institute of Molecular Genetics in Moscow. It was designed as a truncated analog of adrenocorticotropic hormone, retaining only the fragment spanning residues four through ten. Investigators sought a peptide that would preserve the cognitive effects associated with ACTH while eliminating the hormonal stimulation of the adrenal cortex. The compound entered clinical use in Russia during the following decade.
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.
Circulation time for the peptide is short because peptidases cleave it readily. The Pro-Gly-Pro tail is thought to slow breakdown compared with the bare ACTH fragment, but the gain appears modest. Absorption after intranasal dosing is limited, and only a fraction of a dose is expected to reach the central nervous system. Laboratory concentrations therefore sit well above levels achieved systemically, a gap that complicates translation from bench findings to clinical claims.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic heptapeptide | Analog of an ACTH fragment |
| Amino acid length | Seven residues | Met-Glu-His-Phe-Pro-Gly-Pro |
| Origin | Moscow, 1980s | Institute of Molecular Genetics |
| Approved regions | Russia and some neighboring states | Not cleared in Western markets |
| Common trade names | Multiple national brands | Sold as a nasal formulation |
Semax 是人工设计的七肽，序列为 Met-Glu-His-Phe-Pro-Gly-Pro，骨架取自促肾上腺皮质激素片段 ACTH(4-10)。它于二十世纪八十年代在苏联的分子遗传学研究机构内合成。设计目标是保留该片段与注意力和记忆相关的活性，同时剔除促皮质激素释放等内分泌作用。此后俄罗斯将其登记为药品并进入临床使用。
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。
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.
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 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。
=== Connective tissue research === Schleip, R.; Klingler, W.; Wearing, S.; Naylor, I.; Zuegel, M.; Hoppe, K. (2016). "Functional in vitro tension measurements of fascial tissue – a novel modified superfusion approach". Musculoskeletal Neuronal Interactions. 16 (3): 256–260. PMC 5114348. PMID 27609040. Schleip, R.; Wilke, J.; Schreiner, S.; Wetterslev, M.; Klingler, W. (2018). "Needle biopsy-derived myofascial tissue samples are sufficient for quantification of myofibroblast density". Clinical Anatomy. 31 (3): 368–372. doi:10.1002/ca.23040. PMID 29314236.
Guanidinoacetate methyltransferase deficiency (GAMT deficiency) is an autosomal recessive cerebral creatine deficiency that primarily affects the nervous system and muscles. It is the first described disorder of creatine metabolism, and results from deficient activity of guanidinoacetate methyltransferase, an enzyme involved in the synthesis of creatine. Clinically, affected individuals most commonly present with developmental delays, behavior disorders, and seizures. Diagnosis can be suspected on clinical findings, and must be confirmed by specific biochemical tests, brain magnetic resonance spectroscopy, or genetic testing as it is a genetic disorder. Biallelic pathogenic variants in the GAMT gene are the underlying cause of the disorder. After GAMT deficiency is diagnosed, it can be treated by dietary adjustments, including supplementation with creatine. Treatment is highly effective if started early in life but is demanding for parents and caretakers with several doses of creatine, L-ornithine and sodium benzoate needed daily. If treatment is started late, it cannot reverse brain damage which has already taken place. The prevalence of GAMT deficiency is estimated to be 1:250,000.
== Nomenclature == This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is shikimate:NADP+ 3-oxidoreductase. Other names in common use include:
Sources: en.wikipedia.org
Inflammation of the fetal membranes is called chorioamnionitis. Balanced inflammation is an important factor in maintaining fetal membranes by regulating the remodeling. However, if the inflammatory response increases above this level it can have dangerous and potentially fatal effects for the mother and child. These elevated levels of inflammatory molecules in the fetal membrane is called 'sterile inflammation'. Sterile inflammation can be caused by both microbial infection and non-infectious factors, such as senescence of fetal membranes. Senescence is associated with the aging of actively cycling and dividing cells. As the fetal membrane cells proliferate during remodelling, the telomeres (short length or non-coding DNA on the end of chromosomes that protect essential coding DNA from degradation during replication) shorten as chromosomes can not be copied end-to-end fully. Once the telomeres have reached a critical length the cell can no longer divide and can hence cause telomere-dependent replicative senescence. This should occur naturally at term (37 weeks), as it is an important factor to increase the inflammatory environment in the uterus to initiate parturition. However, fetal membrane senescence can be accelerated by oxidative stress and hence, stimulate sterile inflammation to occur prior to term; consequently, causing preterm birth.
==== Attitude to liberalism and personal relations ==== The early focus of the Black Consciousness Movement (BCM) was on criticising anti-racist white liberals and liberalism itself, accusing it of paternalism and being a "negative influence" on black Africans. In one of his first published articles, Biko stated that although he was "not sneering at the [white] liberals and their involvement" in the anti-apartheid movement, "one has to come to the painful conclusion that the [white] liberal is in fact appeasing his own conscience, or at best is eager to demonstrate his identification with the black people only insofar as it does not sever all ties with his relatives on his side of the colour line." Biko and SASO were openly critical of NUSAS' protests against government policies. Biko argued that NUSAS merely sought to influence the white electorate; in his opinion, this electorate was not legitimate, and protests targeting a particular policy would be ineffective for the ultimate aim of dismantling the apartheid state. SASO regarded student marches, pickets, and strikes to be ineffective and stated it would withdraw from public forms of protest. It deliberately avoided open confrontation with the state until such a point when it had a sufficiently large institutional structure. Instead, SASO's focus was on establishing community projects and spreading Black Consciousness ideas among other black organisations and the wider black community.
=== Formulation and delivery === Delivery systems are primarily divided into polymer-based delivery systems (microspheres and liposomes) and live delivery systems (gram-positive bacteria, gram-negative bacteria and viruses)
Sources: en.wikipedia.org
It originated at the Institute of Molecular Genetics in Moscow during the 1980s. The work was carried out by a Russian research group that specialized in peptide neuropharmacology.
It is registered as a medicine in Russia and has been used clinically there for decades. No regulatory agency in Western Europe or North America has approved it for any indication.
Semax corresponds to the four-to-ten fragment of adrenocorticotropic hormone. Because it omits the first three residues, it lacks the adrenal-stimulating action of the full hormone.
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.