ACTH(4-10) raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2025-09-21. Anything still debated is marked as such rather than presented as settled.
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.
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.
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.
| 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 |
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.
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.
=== From lifestyle === Habitual snoring may be a risk factor for MASLD. Severe snoring often signals the presence of obstructive sleep apnea (OSA), a much more serious breathing condition. Blockage or narrowing of the airways, even temporarily, can cause the body to experience lowered oxygen levels in the blood. This, in turn, may cause a variety of changes within the body, such as tissue inflammation, increased insulin resistance, and liver injury. A prospective cohort study found the association between habitual snoring and MASLD development to be significant, and the trend was noted to be most prominent in lean individuals.
=== Persistence in the environment and accumulation in the food chain === DDT was the first organic insecticide. It was introduced during WW2, and was widely used. One use was vector control and it was sprayed on open water. It degrades slowly in the environment, and it is lipophilic (fat soluble). It became the first global pollutant, and the first pollutant to accumulate and magnify in the food chain. During the 1950s and 1960s these very undesirable side effects were recognized, and after some often contentious discussion, DDT was banned in many countries in the 1960s and 1970s. Finally in 2001 DDT and all other persistent insecticides were banned via the Stockholm Convention. Since many decades the authorities require new insecticides to degrade in the environment and not to bioaccumulate.
The total mark obtained by a student through moderation cannot exceed 95; if it does, it is "capped" at 95 unless the student's actual mark is 96 or higher. This is why a mark of 95 is relatively common for such subjects and why it is "much" tougher to get 96 than to get 95. Moderation was also applied in the infamous CBSE Class 12 mathematics papers of 2015 and 2016, which created a huge furore as students and teachers complained that the exams were too harsh. Despite a reportedly heavy offset of +16 (+15 for Delhi), students' marks reduced (especially for 2016), as while the A1 cutoff was stable (90), the A2 cutoff reduced to 77, with other grades also experiencing a dip in cutoff. Moderation can also take the form of giving grace marks to enable students who have scored near the pass mark to pass. This is why marks between 25 and 33 are unheard of in subjects like Mathematics, and it also explains why the difference between the D1 and D2 cutoffs is sometimes minimal.
== Industrial sources == The majority of l-cysteine is obtained industrially by hydrolysis of animal materials, such as poultry feathers or hog hair. Despite widespread rumor, human hair is rarely a source material. Indeed, food additive or cosmetic product manufactures may not legally source from human hair in the European Union. Some animal-originating sources of l-cysteine as a food additive contravene kosher, halal, vegan, or vegetarian diets. To avoid this problem, synthetic l-cysteine, compliant with Jewish kosher and Muslim halal laws, is also available, albeit at a higher price. The typical synthetic route involves fermentation with an artificial E. coli strain. Alternatively, Evonik (formerly Degussa) introduced a route from substituted thiazolines. Pseudomonas thiazolinophilum hydrolyzes racemic 2‑amino-Δ2‑thiazoline-4‑carboxylic acid to l‑cysteine.
For example, in the case of the GCN4 leucine zipper protein, mutants with the a, d pair of I, L resulted in a two-stranded coiled-coil, while a pair of I, I resulted in a three-stranded coiled-coil and a pair of L, I resulted in a four-stranded coiled coil. Thus, the oligomerization selectivity can be tuned on a coiled-coil motif by choosing the appropriate amino acid residues in positions a, d. The polar residues on positions e, g of a heptad also contribute to the stability and specificity of the coiled-coil motif due to the electrostatic interactions such as salt bridges with e, g residues on other heptads, though to a lesser extent compared to residues in the a, d positions. However, e, g residues are capable of conferring heterospecific properties to a coiled-coil motif, such that a system can be designed whereby strands prefer hetero-oligomerize as opposed to homo-oligomerize. Coiled coils may be either left-handed or right-handed coils – although the majority of coiled-coil proteins found in nature consist of heptads and are left-handed since the handedness of coiled coils opposes the handedness of the alpha helices that comprise them. Right-handed coils have been reported in the literature to contain 11 residue repeats known as undecad repeats (a-b-c-d-e-f-g-h-i-j-k) or 15 residue repeats known as pentadecad repeats (a-b-c-d-e-f-g-h-i-j-k-l-m-n-o), both of which could feature larger hydrophobic cores and larger cavities that would be useful in drug delivery systems to load larger cargo.
Sources: en.wikipedia.org
== Background == The monoisotopic mass is not used frequently in fields outside of mass spectrometry because other fields cannot distinguish molecules of different isotopic composition. For this reason, mostly the average molecular mass or even more commonly the molar mass is used. For most purposes such as weighing out bulk chemicals only the molar mass is relevant since what one is weighing is a statistical distribution of varying isotopic compositions. This concept is most helpful in mass spectrometry because individual molecules (or atoms, as in ICP-MS) are measured, and not their statistical average as a whole. Since mass spectrometry is often used for quantifying trace-level compounds, maximizing the sensitivity of the analysis is usually desired. By choosing to look for the most abundant isotopic version of a molecule, the analysis is likely to be most sensitive, which enables even smaller amounts of the target compounds to be quantified. Therefore, the concept is very useful to analysts looking for trace-level residues of organic molecules, such as pesticide residue in foods and agricultural products. Isotopic masses can play an important role in physics, but physics less often deals with molecules. Molecules differing by an isotope are sometimes distinguished from one another in molecular spectroscopy or related fields; however, it is usually a single isotope change on a larger molecule that can be observed rather than the isotopic composition of an entire molecule.
Dimethocaine, also known as DMC or larocaine, is a compound with local anesthetic and stimulatory effects. The stimulatory effect resembles that of cocaine, although less potent. Similarly to cocaine, dimethocaine is addictive due to its stimulation of the reward pathway in the brain. However, dimethocaine is a legal cocaine replacement in some countries and is listed by the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) under the "synthetic cocaine derivatives" category. The structure of dimethocaine, being a 4-aminobenzoic acid ester, resembles that of procaine. It is found as a white powder at room temperature. When a product sold online in the UK in June 2010, advertised as dimethocaine was tested, it was found to be a mixture of caffeine and lidocaine, and the lack of any dopaminergic stimulant ingredient in such mixes may explain the limited recreational effects reported by many users. Other samples tested have however been shown to contain genuine dimethocaine, and one branded "bath salt" product containing primarily dimethocaine as the active ingredient, was noted to have been particularly subject to abuse by intravenous drug users in Ireland.
The "mirror world" would contain copies of all existing fundamental particles. On 2 May, another twin/pair-world or "bi-worlds" cosmology is shown to theoretically be able to solve the cosmological constant (Λ) problem, closely related to dark energy: two interacting worlds with a large Λ each resulting in a small shared effective Λ. Previous similar models e.g. attempt to explain the baryon asymmetry – why there was more matter than antimatter at the beginning – with a mirror anti-universe. 19 May Scientists report that RNA was found to be formed spontaneously on prebiotic basalt lava glass which is presumed to have been abundantly available on the early Earth. The yellow-billed hornbill of southern Africa, famous for its role in Disney's The Lion King, is reported to be at risk of extinction due to rising temperatures in the region. Boeing starts the one-week second uncrewed test flight of its Starliner space capsule in advance of its first crewed test flight later in 2022. A study estimates losses of 61 metals to help the development of circular economy strategies, showing that usespans of, often scarce, tech-critical metals are short. 20 May – Global warming is projected to substantially erode sleep worldwide.
In normal-phase TLC, the stationary phase is polar. Silica gel is very common in normal-phase TLC. More polar compounds in a sample mixture interact more strongly with the polar stationary phase. As a result, more-polar compounds move less (resulting in smaller RF) while less-polar compounds move higher up the plate (higher RF). A more-polar mobile phase dissolves polar compounds more. As such, all compounds on the TLC plate move higher up the plate in polar solvent mixtures. "Strong" solvents move compounds higher up the plate, whereas "weak" solvents move them less. If the stationary phase is non-polar, like C18-functionalized silica plates, it is called reverse-phase TLC. In this case, non-polar compounds move less and polar compounds move more. The solvent mixture will also be much more polar than in normal-phase TLC.
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.
Registered medical products are most often 0.1% nasal drops. Research suppliers ship lyophilized powder, usually in milligram quantities, which is dissolved before use. The active peptide is the same in both cases; presentation and excipients differ.