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 2026-05-12. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
Development of the compound took place in the Soviet Union during the 1980s, largely through peptide research groups affiliated with the Shemyakin-Ovchinnikov Institute and Moscow State University. Investigators screened fragments of adrenocorticotropic hormone for activity on the central nervous system while attempting to separate cognitive effects from hormonal ones. The shortened sequence was selected because it retained behavioral activity in animal models without stimulating corticosteroid release. Early publications described the molecule as an ACTH(4-10) analog.
| 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 |
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。
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.
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.
=== Pathological mechanism === HLA-B27 is the most researched HLA-B allele due to its high relationship with spondyloarthropathies. Although it is not apparent how HLA-B27 promotes disease, theories exist and can be divided between antigen-dependent and antigen-independent categories.
In England, anatomy was the subject of the first public lectures given in any science; these were provided by the Company of Barbers and Surgeons in the 16th century, joined in 1583 by the Lumleian lectures in surgery at the Royal College of Physicians.
With varying potencies ranging from high to low, it is a partial agonist of several of the serotonin 5-HT1 receptors, including the serotonin 5-HT1A, 5-HT1B, and 5-HT1D receptors, and is a partial agonist of the serotonin 5-HT2 receptors, including the serotonin 5-HT2A, 5-HT2B, and 5-HT2C receptors. The drug also interacts with α2-adrenergic receptors, with the sigma σ1 and σ2 receptors, with the imidazoline I1 receptor, and with other targets. Along with the preceding receptor interactions, MDMA is a potent partial agonist of the rodent trace amine-associated receptor 1 (TAAR1). Conversely however, due to species differences, it is far weaker in terms of potency as an agonist of the human TAAR1. The drug appears to act as a weak partial agonist of the human TAAR1 rather than as an efficacious agonist. In relation to the preceding findings, MDMA has been said to be essentially inactive as a human TAAR1 agonist. TAAR1 activation is thought to auto-inhibit and constrain the effects of amphetamines that possess TAAR1 agonism, for instance MDMA in rodents. Elevation of serotonin, norepinephrine, and dopamine levels by MDMA is believed to mediate most of the drug's effects, including its entactogenic, stimulant, euphoriant, hyperthermic, and sympathomimetic effects. The entactogenic effects of MDMA, including increased sociability, empathy, feelings of closeness, and reduced aggression, are thought to be mainly due to induction of serotonin release.
Although still under investigation, it now appears that the combination of melamine and cyanuric acid has been linked to the acute renal failure in cats and dogs that have eaten the suspect pet foods...." In the United States, five potential vectors of impact on the human food supply have been identified. The first, which has already been acknowledged to have occurred by FDA and USDA officials, is via contaminated ingredients imported for use in pet foods and sold for use as salvage in animal feed which has been fed to some number of hogs and chickens, the meat from which has been processed and sold to some number of consumers: "There is very low risk to human health" in such cases involving pork and poultry. On 1 May 2007, the FDA and USDA stated that millions of chickens fed feed tainted with contaminated pet food had been consumed by an estimated 2.5 to 3 million people. The second potential vector is via contaminated vegetable proteins imported for intended use as animal feed, which has apparently been acknowledged to occur with regard to fish feed in Canada, while the third possible route is via contaminated vegetable proteins imported for intended use in human food products, and the FDA has issued an import alert subjecting all Chinese vegetable proteins to detention without examination. A fourth potential vector is referred to on 10 May 2007 FDA-USDA press conference, viz. incorporation of contaminated vegetable proteins into products intended for human use and subsequent importation.
== Chromatography == Mikhail Tsvet invented chromatography in 1900 during his research on plant pigments. He used liquid-adsorption column chromatography with calcium carbonate as adsorbent and petrol ether/ethanol mixtures as eluent to separate chlorophylls and carotenoids. The method was described on 30 December 1901 at the XI Congress of Naturalists and Physicians (XI съезд естествоиспытателей и врачей) in St. Petersburg. The first printed description was in 1905, in the Proceedings of the Warsaw Society of Naturalists, biology section. He first used the term "chromatography" in print in 1906 in his two papers about chlorophyll in the German botanical journal, Berichte der Deutschen botanischen Gesellschaft. In 1907, he demonstrated his chromatograph for the German Botanical Society. For several reasons, Tsvet's work was long ignored: the violent political upheaval in Russia at the beginning of the 20th century, the fact that Tsvet originally published only in Russian (making his results largely inaccessible to western scientists), and an article denying Tsvet's findings. Richard Willstätter and Arthur Stoll tried to repeat Tsvet's experiments, but because they used an overly aggressive adsorbent (destroying the chlorophyll), they were not able to do so. They published their results, and Tsvet's chromatography method fell into obscurity. It was revived 10 years after his death thanks to Austrian biochemist Richard Kuhn and his student, German scientist Edgar Lederer as well as the work of A. J. Martin and R. L. Synge.
Sources: en.wikipedia.org
== Collaborations == Saladino describes himself as an "adventure buddy" of another carnivore diet influencer, Anthony Gustin, founder of online food store Perfect Keto. The pair visited the Hadza people of Tanzania in 2022, promoting them as a dietary model; Saladino said "The Hadza are the closest thing we have to a time machine." According to science writer Dorsa Amir, "the idea that the 'correct' diet is an ancient one is also the backbone of fads like the paleo diet, [and] Saladino's carnivore diet." Saladino is the founder of Heart & Soil, an Austin, Texas-based company producing food supplements. Saladino co-owns it with fellow carnivore diet influencer Brian Johnson, known as Liver King. Heart & Soil sells bottles of encapsulated organ meat-based supplement products and liver pills. He collaborated with California luxury grocery store Erewhon in 2023 on the store's Raw Animal-Based Smoothie, which mixes kefir (fermented milk), along with other ingredients, with beef organs and "Immunomilk" (a product made of freeze-dried cow's colostrum). The raw milk was supplied by California-based Raw Farms, until it switched to pasteurization after tests of its milk turned up positive for H5N1 influenza A virus. Consuming raw animal meat poses a risk of bacterial infection.
== Treatment == While there currently is no cure for Donohue syndrome, treatments for those with the disease are tailored specifically to the symptoms present in each individual. It is often that a team of medical professionals will come together to treat a patient with this condition in their specific realm of practice such as pediatrics, endocrinology, and dermatology. Treatment will often address specific dysfunctions in the patient, such as skin defects, hormonal imbalances, and normal progression of child growth.
=== Loans === In 2014, the museum conducted its first major loan of artifacts to another institution. Approximately 2,000 objects from its collection went on display at the John Heinz History Center in Pittsburgh, Pennsylvania, on May 31, 2014. Because the Arabia was built in Pittsburgh and Brownsville, Pennsylvania, in 1853, the temporary exhibition was called "Pittsburgh's Lost Steamboat: Treasures of the Arabia". In addition to the artifacts, Heinz curators displayed information about the preservation process and a replica of the mule that represents the only fatality of the sinking. This exhibition ran through January 4, 2015.
== Historical context == Digital technologies are changing traditional agricultural practices. The Food and Agriculture Organization of the United Nations has referred to this change as a revolution: "a 'digital agricultural revolution' will be the newest shift that could help ensure agriculture meets the needs of the global population into the future." Other sources refer to this change as "Agriculture 4.0," indicating its role as the fourth major agricultural revolution. Precise dates of the Fourth Agricultural Revolution are unclear. The World Economic Forum announced that the "Fourth Industrial Revolution" (which includes agriculture) will unfold throughout the 21st century, so the beginning of Agriculture 4.0 is often placed around 2000 or shortly thereafter. Agricultural revolutions denote periods of technological transformation and increased farm productivity. Agricultural revolutions include the First Agricultural Revolution, the Arab Agricultural Revolution, the British/Second Agricultural Revolution, the Scottish Agricultural Revolution, and the Green Revolution/Third Agricultural Revolution. Despite boosting agricultural productivity, past agricultural revolutions left many problems unsolved. For example, the Green Revolution had unintended consequences, like inequality and environmental damage. First, the Green Revolution exacerbated inter-farm and interregional inequality, typically biased toward large farmers with the capital to invest in new technologies.
Sources: en.wikipedia.org
=== R139w === One further single nucleotide polymorphism, found homozygous in 0% to 5% of different ethnic population, is leading to an amino acid exchange on position 139 from arginine to tryptophane. Furthermore, an alternative RNA splicing site is created leading to a loss of the quinone binding site. The variant protein of NQO1*3 has similar stability as its wild-type counterpart. The variation between the two is substrate specific and it has reduced activity for some substrates. It has been recently shown that the NQO1*3 polymorphism may also lead to reduced NQO1 protein expression.
=== Social sciences === Finance: a retirement fund will decay exponentially being subject to discrete payout amounts, usually monthly, and an input subject to a continuous interest rate. A differential equation dA/dt = input − output can be written and solved to find the time to reach any amount A, remaining in the fund. In simple glottochronology, the (debatable) assumption of a constant decay rate in languages allows one to estimate the age of single languages. (To compute the time of split between two languages requires additional assumptions, independent of exponential decay).
== Genes == Most research that has been conducted on CLE peptide signaling has been conducted with Arabidopsis, since this genome contains 32 members of the CLE gene family. CLV3, which belongs to the CLE family of genes, is found within one or more tissues of Arabidopsis. All 32 members of the CLE family share two characteristics that include: encoding of a small protein with a putative secretion signal at their N- termini and contain a conserved CLE motif at or near their C-termini. The 32 members of the CLE gene family originated from mutations of the original gene.
At 08:16 the submarine USS Albacore, which had sighted Ozawa's carrier group, had maneuvered into an ideal attack position; Lieutenant Commander James W. Blanchard selected the closest carrier as his target, which happened to be Taihō, the largest and newest carrier in the Japanese fleet and Ozawa's flagship. As Albacore was about to fire, however, her fire-control computer failed, and the torpedoes had to be fired "by eye". Determined to go ahead with the attack, Blanchard ordered all six torpedoes to be fired in a single spread to increase the chances of a hit.
== Structure and properties == Two crystalline forms are known. Orthorhombic β-K2SO4 is the common form, but it converts to α-K2SO4 above 583 °C. These structures are complex, although the sulfate adopts the typical tetrahedral geometry.
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 a synthetic peptide of seven amino acids. Its backbone corresponds to a fragment of adrenocorticotropic hormone extended at the carboxyl end. The material is distributed as a lyophilized solid for laboratory use.