If you have been reading about ACTH analog 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.
The parent fragment ACTH(4-10) carries the sequence Met-Glu-His-Phe-Arg-Trp-Gly. Semax replaces the arginine and tryptophan positions with a proline-glycine-proline tail, giving Met-Glu-His-Phe-Pro-Gly-Pro. That change removes residues associated with adrenal stimulation, so the peptide does not drive cortisol release the way full ACTH does. This distinction shapes how the compound is grouped in the literature, where it sits with neuropeptides and peptide neuromodulators rather than with corticosteroids.
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.
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。
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。
| 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 |
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 seven-amino-acid peptide whose sequence extends the ACTH(4-10) fragment with a C-terminal proline-glycine-proline tripeptide. The commonly cited sequence is Met-Glu-His-Phe-Pro-Gly-Pro, giving a molecular formula near C37H51N9O10S and a molecular weight close to 813.9 g/mol. It belongs to the broader class of synthetic ACTH fragments studied for central nervous system effects rather than for adrenal steroid stimulation. In practice the material appears as a lyophilized white powder for laboratory work or as a dilute saline solution in clinical settings.
Development is attributed to researchers at the Institute of Molecular Genetics in Moscow during the early 1980s, building on earlier Soviet work with ACTH fragments. Russian regulatory approval followed for intranasal use, and the compound has remained commercially available there for decades. Most published human data originate from Russian and, later, some Eastern European clinical reports, which are not always accessible in English translation. Outside that region the material is generally handled as a research chemical rather than a licensed medicine.
==== United States ==== In the United States, mescaline was made illegal in 1970 by the Comprehensive Drug Abuse Prevention and Control Act, categorized as a Schedule I hallucinogen. The drug is prohibited internationally by the 1971 Convention on Psychotropic Substances. Mescaline is legal only for certain religious groups (such as the Native American Church by the American Indian Religious Freedom Act of 1978) and in scientific and medical research. In 1990, the Supreme Court ruled that the state of Oregon could ban the use of mescaline in Native American religious ceremonies. The Religious Freedom Restoration Act (RFRA) in 1993 allowed the use of peyote in religious ceremony, but in 1997, the Supreme Court ruled that the RFRA is unconstitutional when applied against states. Many states, including the state of Utah, have legalized peyote usage with "sincere religious intent", or within a religious organization, regardless of race. Synthetic mescaline, but not mescaline derived from cacti, was officially decriminalized in the state of Colorado by ballot measure Proposition 122 in November 2022. While mescaline-containing cacti of the genus Echinopsis are technically controlled substances under the Controlled Substances Act, they are commonly sold publicly as ornamental plants.
In reductive soil and sediments, PCP can be degraded within 14 days to 5 years, depending on the anaerobic soil bacteria that are present. However, adsorption of PCP in soils is pH dependent because it increases under acidic conditions and decreases in neutral and basic conditions.
The product, α‑ketoadipate, is decarboxylated in the presence of NAD+ and coenzyme A to yield glutaryl-CoA, however the enzyme involved in this is yet to be fully elucidated. Some evidence suggests that the 2-oxoadipate dehydrogenase complex (OADHc), which is structurally homologous to the E1 subunit of the oxoglutarate dehydrogenase complex (OGDHc) (E.C 1.2.4.2), is responsible for the decarboxylation reaction. Finally, glutaryl-CoA is oxidatively decarboxylated to crotonyl-CoA by glutaryl-CoA dehydrogenase (E.C 1.3.8.6), which goes on to be further processed through multiple enzymatic steps to yield acetyl-CoA; an essential carbon metabolite involved in the tricarboxylic acid cycle (TCA).
=== Difference and complementarity with two-photon fluorescence (2PEF) === Two-photons fluorescence (2PEF) is a very different process from SHG: it involves excitation of electrons to higher energy levels, and subsequent de-excitation by photon emission (unlike SHG, although it is also a 2-photon process). Thus, 2PEF is a non coherent process, spatially (emitted isotropically) and temporally (broad, sample-dependent spectrum). It is also not specific to certain structure, unlike SHG. It can therefore be coupled to SHG in multiphoton imaging to reveal some molecules that do produce autofluorescence, like elastin in tissues (while SHG reveals collagen or myosin for instance).
Anchoring fibrils (composed largely of type VII collagen) extend from the basal lamina of epithelial cells and attach to the lamina reticularis (also known as the reticular lamina) by wrapping around the reticular fiber (collagen III) bundles. The basal lamina and lamina reticularis together make up the basement membrane. Anchoring fibrils are essential to the functional integrity of the dermoepidermal junction.
Sources: en.wikipedia.org
Isotope masses from: Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001 Isotopic compositions and standard atomic masses from: de Laeter, John Robert; Böhlke, John Karl; De Bièvre, Paul; Hidaka, Hiroshi; Peiser, H. Steffen; Rosman, Kevin J. R.; Taylor, Philip D. P. (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry. 75 (6): 683–800. doi:10.1351/pac200375060683. Wieser, Michael E. (2006). "Atomic weights of the elements 2005 (IUPAC Technical Report)". Pure and Applied Chemistry. 78 (11): 2051–2066. doi:10.1351/pac200678112051. "News & Notices: Standard Atomic Weights Revised". International Union of Pure and Applied Chemistry. 19 October 2005. Half-life, spin, and isomer data selected from the following sources. Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001 National Nuclear Data Center. "NuDat 3.0 database". Brookhaven National Laboratory. Holden, Norman E. (2004). "11. Table of the Isotopes". In Lide, David R. (ed.). CRC Handbook of Chemistry and Physics (85th ed.). Boca Raton, Florida: CRC Press. ISBN 978-0-8493-0485-9.
== Mechanism of action == Acetohexamide binds to an ATP-sensitive K+ (KATP) channel on the cell membrane of pancreatic beta cells. This inhibits the outflux of potassium, which causes the membrane potential to become more positive. This depolarization in turn opens voltage-gated calcium channels. The rise in intracellular calcium leads to increased fusion of insulin granulae with the cell membrane, and therefore increased secretion of insulin.
Casamino acid is the mixture of amino acids produced from acid hydrolysis of casein, a family of phosphoproteins found in mammalian milk. In comparison, tryptone describes casein that has undergone enzymatic degradation by the protease trypsin, leaving many smaller peptide chains alongside the free amino acids. Casamino acid is used as a component of microbiological growth medium to support protein synthesis. However, tryptophan, an essential amino acid, is lost while digesting the casein with strong acids. Providing this abundant source of nitrogen can alter the phenotype of microorganisms, such as bacterial species recognizing nutrient-rich media and reducing their motility, as compared to their typical environmental behaviors.
=== Development of the concept === In 1893, the American botanist Charles Reid Barnes proposed two terms, photosyntax and photosynthesis, for the biological process of synthesis of complex carbon compounds out of carbonic acid, in the presence of chlorophyll, under the influence of light. The term photosynthesis is derived from the Greek phōs (φῶς, 'gleam') and sýnthesis (σύνθεσις, 'arranging together'), while photosyntax comes from sýntaxis (σύνταξις, 'configuration'). Over time, the term photosynthesis came into common usage. Later discovery of anoxygenic photosynthetic bacteria and photophosphorylation necessitated redefinition of the term.
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.
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。