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Semax Background And Chemistry — Quick Reference

By Editorial Desk · published 2026-05-16 · last reviewed 2026-06-01 · Wiki

semax raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.

Reviewed 2026-06-01. Anything still debated is marked as such rather than presented as settled.

Semax Background and Chemistry

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.

Semax Background and Molecular Structure

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 whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. It was developed as a fragment analog of adrenocorticotropic hormone, modeled specifically on the ACTH(4-10) region. The first four residues reproduce that fragment, while a Pro-Gly-Pro tripeptide is appended at the C-terminus. Work on the compound originated in Russia, where it entered clinical use as an intranasal preparation. Its sequence places it among short regulatory peptides studied for effects on the central nervous system rather than on the adrenal axis.

Semax at a glance

PropertyValueNotes
Molecular formulaC37H51N9O10SContains one methionine sulfur atom
Molecular massApproximately 814 DaConsistent with a seven-residue peptide
AppearanceWhite to off-white powderTypical lyophilized form
SolubilityFreely soluble in waterAlso soluble in dimethyl sulfoxide
Typical storage-20 °C, desiccatedLimits methionine oxidation

Semax 的分子背景与结构

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。

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Chemical Identity and Research Background

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.

Background and Development History

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.

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.

Further detail

=== Brand names === Nefazodone has been marketed under a number of brand names including Dutonin (ATTooltip Austria, ESTooltip Spain, IETooltip Ireland, UKTooltip United Kingdom), Menfazona (ESTooltip Spain), Nefadar (CHTooltip Switzerland, DETooltip Germany, NOTooltip Norway, SETooltip Sweden), Nefazodone BMS (ATTooltip Austria), Nefazodone Hydrochloride Teva (USTooltip United States), Reseril (ITTooltip Italy), Rulivan (ESTooltip Spain), and Serzone (AUTooltip Australia, CATooltip Canada, USTooltip United States).

==== Absorption ==== The intestinal absorption of ritonavir requires an aqueous solubility threshold of greater than 1–2 µg/mL, which the drug achieves via an N-methylurea linker that allows it to be formulated for oral administration. The absolute bioavailability in humans has not been definitively established, though animal models indicate an absolute bioavailability between 74% and 76.4%.

=== Age === Binge eating disorder is the most common eating disorder in adults. The limited amount of research that has been done on BED shows that rates of binge eating disorder are fairly comparable among men and women. The lifetime prevalence of binge eating disorder has been observed in studies to be 2.0 percent for men and 3.5 percent for women, higher than that of the commonly recognized eating disorders, anorexia nervosa and bulimia nervosa. However another systematic literature review found the prevalence average to be about 2.3% in women and about 0.3% in men. Lifetime prevalence rates for BED in women can range anywhere from 1.5 to 6 times higher than in men. One literature review found that point prevalence rates for BED vary from 0.1 percent to 24.1 percent depending on the sample. This same review also found that the 12-month prevalence rates vary between 0.1 percent to 8.8 percent. Adolescents also have a high risk of binge eating behavior. Incidence rates of 10.1 and 6.6 per 10,000 person years have been observed in male and female adolescents in the U.S., respectively.

A true ANP stationary phase will be able to function in both the reversed phase and normal phase modes with only the amount of water in the eluent varying. Thus a continuum of solvents can be used from 100% aqueous to pure organic. ANP retention has been demonstrated for a variety of polar compounds on the hydride based stationary phases. Recent investigations have demonstrated that silica hydride materials have a very thin water layer (about 0.5 monolayer) in comparison to HILIC phases that can have from 6–8 monolayers.[1] In addition the substantial negative charge on the surface of hydride phases is the result of hydroxide ion adsorption from the solvent rather than silanols.[2]

Sources: en.wikipedia.org

Supporting material

In May 2010, Robinson won the Republican primary for Oregon's 4th congressional district, taking 79% of the vote to businesswoman Jaynee Germond's 20%. He faced Democratic incumbent Peter DeFazio in the November 2010 general election. Six weeks before the election, $600,000 worth of TV advertisements started to appear in the district, portraying his opponent as "a puppet of the Democratic leadership". It was later revealed that the advertisements, reportedly a surprise to Robinson, were paid for by conservative billionaire hedge fund manager Robert Mercer. (Mercer provided "six-figure financial support" to Robinson again in 2012 and 2014.) Robinson was defeated by 145,091 votes (53.6%) to 120,307 (44.5%) but it was the "best performance" by a Republican in the district "in decades". Robinson vowed to try again in 2012.

=== Stress === Sustained stress can lead to high levels of circulating cortisol (regarded as one of the more important of the several "stress hormones"). Women show larger increases in cortisol than men when chronically stressed.

A gomphosis, also known as a dentoalveolar syndesmosis, or 'peg and socket joint' is a joint that binds the teeth to bony teeth sockets in the maxillary bone and mandible. Gomphos is the Greek word for "bolt". The fibrous connection between a tooth and its socket is a periodontal ligament. Specifically, the connection is made between the maxilla or mandible to the cementum of the tooth. The motion of a gomphosis is minimal, though considerable movement can be achieved over time—the basis of using braces to realign teeth. The joint can be considered a synarthrosis. The gomphosis is the only joint-type in which a bone does not join another bone, as teeth are not technically bone. In modern, more anatomical, joint classification, the gomphosis is simply considered a fibrous joint because the tissue linking the structures is ligamentous. It has been suggested that this permanent soft-tissue attachment was a critical requisite in the evolution of the mammalian (synapsid) tusk.

=== Impaired neutrophil migration and tumor necrosis factor- Alpha === Impaired neutrophil migration (caused by genetic defects, infections, and the aging process) causes increased macrophage activity that can lead to granuloma formation, a hallmark of NL. Furthermore, TNF-α is a pro-inflammatory cytokine that's activated by macrophages, and it plays a critical role in granuloma formation.

== Interactions == Phenibut may mutually potentiate and extend the duration of the effects of other CNS depressants, including anxiolytics, antipsychotics, sedatives, opioids, anticonvulsants, and alcohol.

Sources: en.wikipedia.org

Frequently asked questions

Is semax an approved medicine?

It is registered as a pharmaceutical product in Russia, where it is typically supplied as a nasal solution. In most other countries it is not an approved drug and is traded as a research chemical instead. Approval status depends entirely on the jurisdiction involved.

How is semax usually given in studies?

Most published work uses intranasal administration, matching the route of the registered Russian formulation. Some animal experiments use intravenous or intraperitoneal injection. The route matters because the intact peptide is cleared rapidly from blood, so exposure differs between methods.

What does a purity figure actually tell a buyer?

A purity value describes the share of the powder accounted for by the target peptide, usually by high-performance liquid chromatography. It does not confirm that the sequence is correct, which requires mass spectrometry or amino acid analysis. Purity and identity are separate checks.

What is the amino acid sequence of Semax?

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.

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