Everything below concerns heptapeptide. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-07-15. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
| 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 |
Pharmacological accounts link semax to melanocortin signalling and to modulation of neurotrophic factor expression, particularly brain-derived neurotrophic factor and nerve growth factor. Much of this evidence comes from rodent studies using intranasal delivery, a route chosen because it allows peptides to reach the central nervous system with limited systemic exposure. Whether the same mechanisms operate in humans at comparable magnitude remains an open question. The precise receptor or receptors responsible for the reported behavioural and neuroprotective effects have not been conclusively identified.
Clinical reports describe use in ischaemic stroke, transient ischaemic attack, optic nerve conditions, and cognitive complaints, but most of these studies are small and were conducted in a single region. Systematic reviews have generally described the evidence base as limited in size and variable in methodological quality. Randomised controlled data suitable for international regulatory assessment are scarce. As a result, major treatment guidelines outside Russia do not include the peptide, and interest in it remains largely research-driven rather than routine clinical.
We went to South Ossetia on the night of August 7. Around noon of 7 August, the column was near Tskhinvali on the bypass road." In August 2009, Russian military reporter Alex Kots quoted Andrey Kazachenko, commander of the 693rd Regiment, as saying that the General Staff of Russia issued an order to begin movement towards Tskhinvali at 8:20 PM on August 7. In August 2009, Major of the Medical Service Dmitry Zubok told radio station moskva.fm that several surgeons, including him, were sent to South Ossetia on 14 July 2008 in anticipation of conflict and that the armed hostilities began on 6 August 2008. In September 2009, an independent documentary "Russian Lessons" was premiered in Saint Petersburg. Russian film makers Andrei Nekrasov and Olga Konskaya disputed the narrative of the Russian government (supported by the most Western media at the time) and examined wartime propaganda. The film also includes a testimony by a father of Russian soldier that his son was sent to the war on 5 August 2008.
The pharmacokinetics of ethanol are well characterized by the ADME acronym (absorption, distribution, metabolism, excretion). Besides the dose ingested, factors such as the person's total body water, speed of drinking, the drink's nutritional content, and the contents of the stomach all influence the profile of blood alcohol content (BAC) over time. Breath alcohol content (BrAC) and BAC have similar profile shapes, so most forensic pharmacokinetic calculations can be done with either. Relatively few studies directly compare BrAC and BAC within subjects and characterize the difference in pharmacokinetic parameters. Comparing arterial and venous BAC, arterial BAC is higher during the absorption phase and lower in the postabsorptive declining phase.
In 2016, a set of 355 genes likely present in the LUCA was identified. A total of 6.1 million prokaryotic genes from Bacteria and Archaea were sequenced, identifying 355 protein clusters from among 286,514 protein clusters that were probably common to the LUCA. The results suggest that the LUCA was anaerobic with a Wood–Ljungdahl (reductive Acetyl-CoA) pathway, nitrogen- and carbon-fixing, thermophilic. Its cofactors suggest dependence upon an environment rich in hydrogen, carbon dioxide, iron, and transition metals. Its genetic material was probably DNA, requiring the 4-nucleotide genetic code, messenger RNA, transfer RNA, and ribosomes to translate the code into proteins such as enzymes. LUCA likely inhabited an anaerobic hydrothermal vent setting in a geochemically active environment. It was evidently already a complex organism, and must have had precursors; it was not the first living thing. The physiology of LUCA has been in dispute. Previous research identified 60 proteins common to all life. Metabolic reactions inferred in LUCA are the incomplete reverse Krebs cycle, gluconeogenesis, the pentose phosphate pathway, glycolysis, reductive amination, and transamination.
Although elastin is exceptionally long-lived, its structure and function can change with aging. In human skin, aging has been associated with reductions and structural alterations in dermal elastin and elastic fibers. Imaging studies have reported age-related changes in the amount and organization of dermal elastin, including fragmentation and reduced connectivity of elastic-fiber networks. These changes may contribute to the decline in skin elasticity and firmness associated with aging.
== Osteogenesis == Bone is formed by one of two processes: endochondral ossification or intramembranous ossification. Endochondral ossification is the process of forming bone from cartilage and this is the usual method. This form of bone development is the more complex form: it follows the formation of a first skeleton of cartilage made by chondrocytes, which is then removed and replaced by bone, made by osteoblasts. Intramembranous ossification is the direct ossification of mesenchyme as happens during the formation of the membrane bones of the skull and others. During osteoblast differentiation, the developing progenitor cells express the regulatory transcription factor Cbfa1/Runx2. A second required transcription factor is Sp7 transcription factor. Osteochondroprogenitor cells differentiate under the influence of growth factors, although isolated mesenchymal stem cells in tissue culture may also form osteoblasts under permissive conditions that include vitamin C and substrates for alkaline phosphatase, a key enzyme that provides high concentrations of phosphate at the mineral deposition site. In turn osteoblasts may give rise to osteocytes in a process dependent on the vascular musculature of blood vessels in the bone.
Sources: en.wikipedia.org
== Function == Type IV collagen is the major structural component of basement membranes, which contains two or three COL4A1 proteins. Thus, COL4A1 is abundant and found in all types of basement membranes. The NC1 domain of COL4A1 is an important antiangiogenic molecule to control the formation of new capillaries.
PmF3 + 3 Li → Pm + 3 LiF The promethium sample produced was used to measure a few of the metal's properties, such as its melting point. In 1963, ion-exchange methods were used at ORNL to prepare about ten grams of promethium from nuclear reactor fuel processing wastes. Promethium can be either recovered from the byproducts of uranium fission or produced by bombarding 146Nd with neutrons, turning it into 147Nd, which decays into 147Pm through beta decay with a half-life of 11 days.
== Comparisons with other drugs for type 2 diabetes == A study funded by Novo Nordisk, the U.S. distributor for Repaglinide, compared their product with Nateglinide in "A randomized, parallel-group, open-label, multicenter 16-week clinical trial". They concluded that the two were similar, but "repaglinide monotherapy was significantly more effective than nateglinide monotherapy in reducing HbA1c and FPG values after 16 weeks of therapy."
=== From vitamers === Animals are auxotroph for this enzyme co-factor and require it or an intermediate to be supplemented, hence its classification as a vitamin, unlike MoCo or CoQ10 for example. PLP is synthesized from pyridoxal by the enzyme pyridoxal kinase (gene PDXK), requiring one ATP molecule. PDXK can also produce 5'-phosphates of the other vitamers (pyridoxine and pyridoxamine), with pyridoxine 5′-phosphate oxidase converting these alternative 5'-phosphates into PLP. PLP is made and metabolized in the liver. PLP and other vitamin B6 phosphates can be broken down by pyridoxal phosphatase, which removes the phosphate group.
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.
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.