Semax 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 2026-01-03 and is reviewed periodically as new material appears.
The C-terminal Pro-Gly-Pro extension is not incidental. Proline-rich tails are known to resist several common peptidases, and the published literature attributes the longer half-life of Semax, relative to unmodified ACTH fragments, to this feature. The modification also removes the melanocyte-stimulating and corticosteroidogenic activity that characterizes longer ACTH-derived sequences. Because the molecule is small and hydrophilic, it is typically formulated as an aqueous solution for intranasal or parenteral delivery. Acetylation or amidation at the termini appears in closely related research peptides and shifts the mass by a fixed increment.
Reported pharmacological work centers on neurotrophic signaling, including changes in BDNF and NGF expression in hippocampal tissue in animal models. Human data come largely from studies conducted in Russia, and how well those results generalize to other populations remains an open question. Regulatory status differs sharply by jurisdiction: Semax is a registered prescription medicine in Russia, while it holds no approved marketing status in the United States or the European Union. Outside such jurisdictions it is generally handled as a research chemical, which affects both documentation and quality expectations.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular weight | ~813.9 Da (free heptapeptide) | N-acetylated form is about 42 Da heavier |
| Residue count | 7 (heptapeptide) | Four residues from ACTH(4-10), three added |
| Appearance | White to off-white powder | Usually supplied lyophilized |
| Solubility class | Freely soluble in water | Also dissolves in DMSO and polar organic solvents |
| Related parent fragment | ACTH(4-10) | Parent motif is Met-Glu-His-Phe |
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its chain combines the first seven residues of corticotropin with a C-terminal proline-glycine-proline extension, a modification intended to slow enzymatic breakdown. The free peptide has a molecular mass near 813.9 daltons. It belongs to the class of ACTH-derived fragments studied for central nervous system activity rather than for adrenal steroid stimulation. This structural relationship to a natural hormone fragment is the usual starting point for describing the compound in the literature.
Development took place during the 1980s at institutes of the Russian Academy of Sciences, where peptide fragments of ACTH were screened for cognitive and neuroprotective effects. The compound received regulatory approval in Russia as a nasal preparation, marketed for conditions such as ischemic stroke, transient ischemic attacks, and optic nerve disorders. Registration in other countries has not followed. Most published clinical reports originate from a small number of Russian research groups, and independent replication outside that setting remains limited. The regulatory status therefore differs sharply between Russia and the rest of the world.
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.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It was derived from the ACTH(4-10) fragment, a short segment of adrenocorticotropic hormone that lacks the hormonal activity associated with the full-length peptide. Researchers at the Institute of Molecular Genetics in Moscow developed the compound during the 1980s. It has been registered as a pharmaceutical product in Russia and several neighbouring countries, where it is supplied as a nasal solution, and it is also sold internationally as a research chemical.
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。
==== Excess compensation ==== Effective in 2026, certain tax-exempt organizations must pay an excise tax on compensation exceeding $1 million paid to any current and former employee, rather than only to its top five most highly compensated employees for current and prior years.
On Christmas Eve, Humboldt and his party departed from Callao for Guayaquil, traveling slowly along the coast. During the voyage, Humboldt took regular oceanographic measurements of the cold current along the Peruvian coast. Although local fishermen had known of this current for centuries, Humboldt was the first to systematically study its properties. Over time, despite his protests, this current came to be widely known as the Humboldt Current, and it remains a principal geographical feature associated with his name. On February 15, 1803, Humboldt sailed from Guayaquil to Mexico. Even two hundred miles offshore, he heard the eruption of Cotopaxi. After thirty-three days at sea, the ship approached Acapulco. Humboldt discovered that standard charts had mislocated the port, a significant error given Acapulco’s importance as a hub for Spanish Pacific trade. On March 22, 1803, the ship anchored, and Humboldt began immediate astronomical observations to determine the port’s precise location. He confirmed that Acapulco was situated up to five miles west of its position on existing maps, prompting necessary revisions to the cartography of New Spain.
=== Side effects === Citicoline has a very low toxicity profile in animals and humans. Clinically, doses of 2000 mg per day have been observed and approved. Minor transient adverse effects are rare and most commonly include stomach pain and diarrhea.
=== Antimicrobial Platelets === Platelet-mimicking particles engineered with antimicrobial properties offer a novel approach to combating infections by targeting pathogens at injury sites, enhancing immune responses, and delivering antimicrobial agents directly to affected areas. While platelets are often recognized for their hemostatic role, more recent research focuses on their ability to fight infections by releasing antimicrobial molecules and through interactions with immune cells. Building on these properties, synthetic antimicrobial platelets can be an attractive targeted therapy for preventing and treating infections, particularly in trauma, surgery, and immunocompromised patients. An approach to developing antimicrobial platelet-like particles (PLPs) involves the integration of nanosilver— a material known for its potent antimicrobial activity. Recent findings have reported that nanosilver composite PNIPAM microgels incorporated into PLPs (Ag-PLPs) effectively inhibited bacterial growth while maintaining key platelet functions such as deformability and clot retraction.4 This balance is needed in order for antimicrobial synthetic platelets to induce wound healing as well as hemostasis, while keeping infection risk at minimum. Ag-PLPs, in a wound experimental model, not only increased clot retraction but also performance of healing, suggesting its regard as a "two-in-one therapy" for high-risk infection trauma patients.
== History == The 426th Reconnaissance Group was activated at Gainesville Army Air Field, Texas on 1 July 1943. It was apparently never fully organized, although its 45th Reconnaissance Squadron and 47th Liaison Squadron apparently began to receive aircraft. These two squadrons were transferred out of the group on 11 August 1943, and the group and its remaining components were disbanded four days later. The group was reconstituted in 1983 as the 426th Tactical Intelligence Group, but has not been active since then.
Sources: en.wikipedia.org
=== Waterways === Scammonden Reservoir, Deanhead Reservoir – both in the moors near Ripponden River Aire, River Calder, River Hebble, River Spen, River Worth Aire and Calder Navigation Calder and Hebble Navigation Huddersfield Broad Canal Huddersfield Narrow Canal, Standedge Tunnel Leeds and Liverpool Canal Rochdale Canal
== External links == alpha-Fetoproteins at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Overview of all the structural information available in the PDB for UniProt: P02771 (Alpha-fetoprotein) at the PDBe-KB.
On the other hand, inside a population, the presence of many different alleles ensures there will always be an individual with a specific MHC molecule able to load the correct peptide to recognize a specific microbe. The evolution of the MHC polymorphism ensures that a population will not succumb to a new pathogen or a mutated one, because at least some individuals will be able to develop an adequate immune response to win over the pathogen. The variations in the MHC molecules (responsible for the polymorphism) are the result of the inheritance of different MHC molecules, and they are not induced by recombination, as it is the case for the antigen receptors. Because of the high levels of allelic diversity found within its genes, MHC has also attracted the attention of many evolutionary biologists, as well as disease specialists.
Descriptive human anatomy often uses terminology that is fairly correct descriptive Latin. For example, musculus gluteus maximus simply means the "largest rump muscle", where musculus was Latin for "little mouse" and applied to muscles; a frenum, a structure for keeping something in place, is Latin for bridle; and a foramen is Latin for a passage or perforation.
Sources: en.wikipedia.org
The sequence is Met-Glu-His-Phe-Pro-Gly-Pro, a seven-residue peptide. The first four residues correspond to the ACTH(4-10) fragment, and Pro-Gly-Pro is added at the C-terminus. N-acetylated versions also appear in the literature and differ in mass.
Semax is a synthetic analog of the ACTH(4-10) fragment rather than a copy of the full hormone. Truncation plus the added tail removes the steroidogenic portion of ACTH. That distinction explains why it is studied for nervous-system effects instead of adrenal stimulation.
It is registered as a prescription product in Russia and has been used there clinically, chiefly by the intranasal route. No approval exists in the United States or the European Union. Availability elsewhere typically falls under research-chemical distribution, with varying purity documentation.
It is described as a synthetic analogue of the ACTH(4–10) fragment, a short segment of adrenocorticotropic hormone. Its sequence differs from that fragment and includes two proline residues, which influence stability and behaviour in solution.