nasal formulation 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.
Last reviewed on 2025-08-15. Where a claim depends on a specific study, the study is described rather than over-claimed.
The proposed mechanism centres on neurotrophic signalling rather than direct receptor activation. Semax is reported to increase expression of brain-derived neurotrophic factor and nerve growth factor in several brain regions, and to shift the balance between excitatory and inhibitory neurotransmitter systems. Interaction with melanocortin receptors has been suggested because of the parent ACTH fragment. Many of these findings come from rodent studies, and the extent to which they translate to human physiology remains an open question.
Scientific literature on semax is unevenly distributed. A substantial share of published work originates from a small number of laboratories in Russia, while independent replication elsewhere is limited. Human data consist mostly of small trials with short follow-up, and several reported outcomes rely on subjective rating scales. Questions about how much intact peptide reaches the central nervous system after nasal administration, and how long it persists there, are still unresolved. The compound is best described as an active research subject rather than a settled pharmacological agent.
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。
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Calculated for the free peptide |
| Molar mass | 813.9 g/mol | Anhydrous free base |
| Peptide class | Synthetic heptapeptide | ACTH(4-10) analogue |
| Parent fragment | ACTH(4-10) | Adrenocorticotropic hormone segment |
| Developmental origin | Institute of Molecular Genetics, Moscow | Work began in the 1980s |
Laboratory work points toward modulation of neurotrophic signaling, particularly expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal tissue. Studies also describe effects on monoamine turnover, inflammatory mediators, and oxidative markers. These observations come mainly from animal models and cultured cells, so the causal chain in humans is not firmly established. Whether the reported molecular changes translate into measurable clinical benefit is an open question. Reviews generally present the mechanism as plausible rather than demonstrated.
Clinical evidence consists largely of small trials with modest sample sizes, often without independent replication. Reported endpoints include cognitive scores, recovery after stroke, and visual function, but study designs vary widely and few trials meet contemporary reporting standards. Systematic reviewers have noted a high risk of bias in several of these reports. No large multicenter trial conducted outside Russia has been published. The compound is therefore best described as investigational in most jurisdictions, with its clinical role still unresolved.
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.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It is described in the literature as an analogue of the ACTH(4–10) fragment, a short N-terminal portion of adrenocorticotropic hormone that retains some neurotropic activity without the full hormonal effects of the parent peptide. The molecule carries a methionine residue at the N-terminus and two proline residues near the C-terminus, features that shape both its interactions with receptor systems and its chemical stability. The free peptide corresponds to the formula C37H51N9O10S and a molecular mass near 813.9 Da.
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.
On February 11, 2015, Newsom announced that he was opening a campaign account for governor in the 2018 elections, allowing him to raise funds for a campaign to succeed Brown as governor of California. On June 5, 2018, he finished in the top two in the nonpartisan blanket primary, and he defeated Republican John H. Cox by a landslide in the November 6 general election.
Pretargeting (imaging) is a tool for nuclear medicine and radiotherapy. Imaging studies require a high contrast of target to background. This can be provided by using a biomarker which has a high affinity and specificity for its target (e.g. an antibody).
Mendelevium is a synthetic chemical element; it has symbol Md (formerly Mv) and atomic number 101. A metallic radioactive transuranium element in the actinide series, it is the first element by atomic number that currently cannot be produced in macroscopic quantities by neutron bombardment of lighter elements. It is the thirteenth actinide, the ninth transuranic element, and the first transfermium; it is named after Dmitri Mendeleev, the father of the periodic table. Like all the transfermiums, it can only be produced in particle accelerators by bombarding lighter elements with charged particles. The element was first produced in 1955 by bombarding einsteinium with alpha particles, the method still used today. Using commonly-available microgram quantities of einsteinium-253, over a million mendelevium atoms may be made each hour. The chemistry of mendelevium is typical for the late actinides, with a dominant +3 oxidation state but also a +2 oxidation state accessible in solution. All known isotopes of mendelevium have short half-lives; there are currently no uses for it outside basic scientific research, and only small amounts are produced.
== Structure == This group of cysteine peptidases belong to MEROPS peptidase family C60 (clan C-) and include the members of several subfamilies of sortases. Another sub-family of sortases (C60B in MEROPS) contains bacterial sortase B proteins that are approximately 200 residues long. The protein cleaving and ligating function of the sortase enzyme is reliant on the structure of the enzyme binding site and the presence of the correct binding site on the target protein. The requirement of a binding motif limits the versatility of the sortase enzyme and requires the addition of a short protein tag in cases when the desired protein doesn't contain the necessary binding site.
Fine structure of taste buds in the barbel of the catfish, Ictalurus punctatus. Cell Tissue Res 169, 395–403. Hawkins, M. B. (n.d.). The development and evolutionary origin of barbels in the channel catfish Ictalurus punctatus (Siluriformes: Ictaluridae). 48. Joyce, E. C. and Chapman, G. B. (1978). Fine structure of the nasal barbel of the channel catfish, Ictalurus punctatus. Journal of Morphology 158, 109–153. Kapoor, B. G., Evans, H. E., & Pevzner, E. A. (1976). The Gustatory System in Fish. In Advances in Marine Biology (Vol. 13, pp. 53–108). Elsevier. https://doi.org/10.1016/S0065-2881(08)60280-1 LeClair, E.E. and Topczewski, J. (2009). Methods for the study of the zebrafish maxillary barbel. J Vis Exp, http://www.jove.com/video/1558/methods-for-the-study-of-the-zebrafish-maxillary-barbel?id=1558, doi:10.3791/1558. LeClair, E.E. and Topczewski, J. (2010). Development and regeneration of the zebrafish maxillary barbel: a novel study system for vertebrate tissue growth and repair. PLoS One 5, e8737. McCormick, M. I. (1993). Development and changes at settlement in the barbel structure of the reef fish, Upeneus tragula (Mullidae). Environmental Biology of Fishes, 37(3), 269–282. https://doi.org/10.1007/BF0000463 Ogawa, K., Marui, T. and Caprio, J. (1997). Bimodal (taste/tactile) fibers innervate the maxillary barbel in the channel catfish. Chem Senses 22, 477–82. von der Emde, G., Mogdans, J., & Kapoor, B. G. (Eds.). (2004). The Senses of Fish. Springer Netherlands.
Sources: en.wikipedia.org
=== Targets === Aptamer targets can include small molecules and heavy metal ions, larger ligands such as proteins, and even whole cells. These targets include lysozyme, thrombin, human immunodeficiency virus trans-acting responsive element (HIV TAR), hemin, interferon γ, vascular endothelial growth factor (VEGF), prostate specific antigen (PSA), dopamine, and the non-classical oncogene, heat shock factor 1 (HSF1). Aptamers have been generated against cancer cells, prions, bacteria, and viruses. Viral targets of aptamers include influenza A and B viruses, Respiratory syncytial virus (RSV), SARS coronavirus (SARS-CoV) and SARS-CoV-2. Aptamers may be particularly useful for environmental science proteomics. Antibodies, like other proteins, are more difficult to sequence than nucleic acids. They are also costly to maintain and produce, and are at constant risk of contamination, as they are produced via cell culture or are harvested from animal serum. For this reason, researchers interested in little-studied proteins and species may find that companies will not produce, maintain, or adequately validate the quality of antibodies against their target of interest. By contrast, aptamers are simple to sequence and cost nothing to maintain, as their exact structure can be stored digitally and synthesized on demand. This may make them more economically feasible as research tools for underfunded biological research subjects. Aptamers exist for plant compounds, such as theophylline (found in tea) and abscisic acid (a plant immune hormone).
=== Death === De Duve died on 4 May 2013, at his home in Nethen, Belgium, aged 95. He decided to end his life by legal euthanasia, performed by two doctors and in the presence of his four children. He had been long suffering from cancer and atrial fibrillation, and his health problems were exacerbated by a recent fall in his home. De Duve was cremated as he had willed, and his ashes were distributed among family members and friends.
===== Topical ===== Some popular plant juices sold as hair serum may, instead of growing human hair, actually inhibit the growth, including 6-gingerol found in ginger. Among the indigenous peoples of California, plants in the genus Marah were used as a topical treatment for hair loss, with the seeds roasted, mashed, and applied to the scalp as a salve. The cucurbitacins found in Marah are structurally similar to finasteride.
=== Safer supply === Safer supply programs prescribe medications (including stimulants, opioids, and benzodiazepines) to people at high risk of overdose. This is meant to provide a safer alternative to an illegal drug supply that contains high levels of fentanyl and other dangerous chemicals. The structure of such programs is more flexible than opioid agonist therapy. The drugs dispensed by these programs can result in intoxication, unlike methadone or buprenorphine. Safer supply projects exist in a number of Canadian cities. Critics of these programs point to the risk of drug diversion and argue that patients should be encouraged to enter drug rehabilitation programs instead of being given drugs.
Sources: en.wikipedia.org
Semax is based on the ACTH(4-10) fragment, a seven-amino-acid segment of adrenocorticotropic hormone. The synthetic peptide retains the core sequence while removing regions associated with endocrine activity. This modification is intended to isolate effects on the nervous system.
It is registered for clinical use in Russia and a few other countries, typically as a nasal drop formulation. It does not hold approval from the United States Food and Drug Administration or the European Medicines Agency. Outside those markets it is generally handled as a research chemical.
The compound was developed in Moscow and the earliest studies were conducted there, so the primary literature is largely in Russian-language journals. Translation and indexing have been incomplete, which limits access for outside researchers. Independent groups have since published some work, but the total volume remains modest.
不是。Semax 是完全人工合成的七肽，自然界中没有对应的已知肽段。它的设计灵感来自促肾上腺皮质激素片段 ACTH(4-10)，但序列经过了替换和延长。