Everything below concerns nasal formulation. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2025-12-29. 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.
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.
Later generations of the molecule include an N-acetylated form and an amidated form, both marketed online alongside the parent peptide. These variants differ in terminal chemistry and stability, and they are frequently discussed in the same breath even though they have not been compared in controlled trials. Supply outside formal healthcare systems comes largely from laboratories that synthesize peptides to order. Purity and identity of these materials vary widely, and no single body oversees the international trade.
Semax is a synthetic heptapeptide developed in the Soviet Union during the 1980s by researchers at the Institute of Molecular Genetics in Moscow. It was designed as a truncated analog of adrenocorticotropic hormone, retaining only the fragment spanning residues four through ten. Investigators sought a peptide that would preserve the cognitive effects associated with ACTH while eliminating the hormonal stimulation of the adrenal cortex. The compound entered clinical use in Russia during the following decade.
| 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 |
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.
Regulatory status differs sharply between jurisdictions. In Russia the peptide is registered as a prescription nasal preparation, while agencies such as the United States Food and Drug Administration have not approved it for any indication. Products sold elsewhere are typically labeled for laboratory research only, and such labels shift responsibility for safe handling to the purchaser. Because the same name covers pharmaceutical-grade nasal drops and bulk research powder, identity and purity documentation becomes the main practical concern when comparing sources.
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.
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.
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 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.
The Gold Book, formally titled Compendium of Chemical Terminology, contains internationally accepted definitions for terms in chemistry. Work on the first edition was initiated by Victor Gold, thus spawning its informal name. The first edition was published in 1987 (ISBN 0-63201-765-1). The second (ISBN 0-86542-684-8), edited by A. D. McNaught and A. Wilkinson, was published in 1997. A slightly expanded version is also freely searchable online. Translations have also been published in French, Spanish and Polish.
=== Biological fluorescence === Chemical biologists often study the functions of biological macromolecules using fluorescence techniques. The advantage of fluorescence versus other techniques resides in its high sensitivity, non-invasiveness, safe detection, and ability to modulate the fluorescence signal. In recent years, the discovery of green fluorescent protein (GFP) by Roger Y. Tsien and others, hybrid systems and quantum dots have enabled assessing protein location and function more precisely. Three main types of fluorophores are used: small organic dyes, green fluorescent proteins, and quantum dots. Small organic dyes usually are less than 1 kDa, and have been modified to increase photostability and brightness, and reduce self-quenching. Quantum dots have very sharp wavelengths, high molar absorptivity and quantum yield. Both organic dyes and quantum dyes do not have the ability to recognize the protein of interest without the aid of antibodies, hence they must use immunolabeling. Fluorescent proteins are genetically encoded and can be fused to your protein of interest. Another genetic tagging technique is the tetracysteine biarsenical system, which requires modification of the targeted sequence that includes four cysteines, which binds membrane-permeable biarsenical molecules, the green and the red dyes "FlAsH" and "ReAsH", with picomolar affinity. Both fluorescent proteins and biarsenical tetracysteine can be expressed in live cells, but present major limitations in ectopic expression and might cause a loss of function.
Ever since the first discovery of Tyrannosaurus most scientists have agreed that it was an active predator, though like modern large predators it would readily scavenge or steal another predator's kill if it had the opportunity. Paleontologist Jack Horner has been a major proponent of the view that Tyrannosaurus was not a predator at all but instead was an obligate scavenger. He has put forward arguments in the popular literature to support the pure scavenger hypothesis:
Disulfur decafluoride is a chemical compound with the formula S2F10. It was discovered in 1934 by Denbigh and Whytlaw-Gray. Each sulfur atom of the S2F10 molecule is octahedral, and surrounded by five fluorine atoms and one sulfur atom. The two sulfur atoms are connected by a single bond. In the S2F10 molecule, the oxidation state of each sulfur atoms is +5, but their valency is 6 (they are hexavalent). It is a colorless liquid with a burnt match smell similar to sulfur dioxide.
== Structure == BOLD-100 has an octahedral structure with two trans indazoles and four chloride ligands in the equatorial plane. The primary cation for BOLD-100 is sodium. BOLD-100's impurity profile contains trace quantities of cesium
Sources: en.wikipedia.org
In this highly stable hierarchy, the pharmacists—and even pharmacist assistants—were assigned status superior to all others in health-related fields such as physicians and acupuncturists. In the Imperial household, the pharmacist was even ranked above the two personal physicians of the Emperor. There is a stone sign for a pharmacy shop with a tripod, a mortar, and a pestle opposite one for a doctor in the Arcadian Way in Ephesus near Kusadasi in Turkey. The current Ephesus dates back to 400 BC and was the site of the Temple of Artemis, one of the seven wonders of the world. In Baghdad the first pharmacies, or drug stores, were established in 754, under the Abbasid Caliphate during the Islamic Golden Age. By the 9th century, these pharmacies were state-regulated. The advances made in the Middle East in botany and chemistry led medicine in medieval Islam substantially to develop pharmacology. Muhammad ibn Zakarīya Rāzi (Rhazes) (865–915), for instance, acted to promote the medical uses of chemical compounds. Abu al-Qasim al-Zahrawi (Abulcasis) (936–1013) pioneered the preparation of medicines by sublimation and distillation. His Liber servitoris is of particular interest, as it provides the reader with recipes and explains how to prepare the "simples" from which were compounded the complex drugs then generally used. Sabur Ibn Sahl (d 869), was, however, the first physician to record his findings in a pharmacopoeia, describing a large variety of drugs and remedies for ailments.
The risk information seeking and processing (RISP) model analyzes social implications that affect attitudes and decision making pertaining to clinical trials. People who hold a higher stake or interest in the treatment provided in a clinical trial showed a greater likelihood of seeking information about clinical trials. Cancer patients reported more optimistic attitudes towards clinical trials than the general population. Having a more optimistic outlook on clinical trials also leads to greater likelihood of enrolling.
== Factors affecting enzyme activity == As enzymes are made up of proteins, their actions are sensitive to change in many physio chemical factors such as pH, temperature, substrate concentration, etc. The following table shows pH optima for various enzymes.
Soft tissue is tissue in the body that connects and surrounds or supports internal organs and bones, and includes muscle, tendons, ligaments, fat, fibrous tissue, lymph and blood vessels, fasciae, and synovial membranes. Soft tissue is not hardened by the processes of ossification or calcification such as bones and teeth. It is sometimes defined by what it is not – such as "nonepithelial, extraskeletal mesenchyme exclusive of the reticuloendothelial system and glia".
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 originated at the Institute of Molecular Genetics in Moscow during the 1980s. The work was carried out by a Russian research group that specialized in peptide neuropharmacology.