ACTH(4-10) raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-05-22. Anything still debated is marked as such rather than presented as settled.
The compound was developed in the 1980s at the Institute of Molecular Genetics in Moscow, where it emerged from research on short ACTH fragments and their effects on the central nervous system. Russian pharmaceutical listings describe it as a nootropic and neuroprotective agent, most often formulated as nasal drops. It is not a marketed medicine in the United States or the European Union, and no pharmacopoeial monograph covers it. Consequently, most published clinical experience with the substance originates from a small number of research centres, mainly in Russia and neighbouring countries.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Free acid form of the heptapeptide; depends on terminal groups |
| Molecular mass | About 813.9 g/mol | Average mass used for mass spectrometry confirmation |
| Appearance | White to off-white solid | Supplied as a lyophilised powder; hygroscopic |
| Solubility class | Freely soluble in aqueous media | Water, saline, and phosphate buffers; limited organic solubility |
| Typical storage temperature | -20 degrees Celsius | Long term and dry; short working periods may use 2 to 8 degrees Celsius |
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.
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 是人工设计的七肽，序列为 Met-Glu-His-Phe-Pro-Gly-Pro，骨架取自促肾上腺皮质激素片段 ACTH(4-10)。它于二十世纪八十年代在苏联的分子遗传学研究机构内合成。设计目标是保留该片段与注意力和记忆相关的活性，同时剔除促皮质激素释放等内分泌作用。此后俄罗斯将其登记为药品并进入临床使用。
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。
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.
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.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its chain combines the first seven residues of corticotropin with a C-terminal proline-glycine-proline extension, a modification intended to slow enzymatic breakdown. The free peptide has a molecular mass near 813.9 daltons. It belongs to the class of ACTH-derived fragments studied for central nervous system activity rather than for adrenal steroid stimulation. This structural relationship to a natural hormone fragment is the usual starting point for describing the compound in the literature.
Development took place during the 1980s at institutes of the Russian Academy of Sciences, where peptide fragments of ACTH were screened for cognitive and neuroprotective effects. The compound received regulatory approval in Russia as a nasal preparation, marketed for conditions such as ischemic stroke, transient ischemic attacks, and optic nerve disorders. Registration in other countries has not followed. Most published clinical reports originate from a small number of Russian research groups, and independent replication outside that setting remains limited. The regulatory status therefore differs sharply between Russia and the rest of the world.
== Research == As of October 2025, seltorexant is in phase 3 clinical trials for treatment of major depressive disorder (MDD) and phase 2 trials for treatment of insomnia and Alzheimer's disease. It was also under investigation for the treatment of sleep apnea, but no recent development has been reported for this indication. Seltorexant is under development by Minerva Neurosciences and Johnson & Johnson's Janssen Pharmaceuticals. Seltorexant is being explored at doses of 5 to 80 mg. In the early clinical trials conducted so far, seltorexant has been found to improve depression scores on the Hamilton Depression Rating Scale in people with MDD and to improve sleep onset, total sleep time, time awake after sleep onset, and sleep efficiency in people with MDD and/or insomnia.
=== Nutritional content === At birth, the composition of breast milk corresponds in quality to the specific needs of the infant. The pattern of intended nutrient content in breast milk is relatively consistent. Breastmilk is made from nutrients in the mother's bloodstream and bodily stores. It has an optimal balance of fat, sugar, water, and protein that is needed for a baby's age-appropriate growth and development. That being said, a variety of factors can influence the nutritional makeup of breastmilk, including gestational age, age of infant, maternal age, maternal smoking, and nutritional needs of the infant. The first type of milk produced is called colostrum. The volume of colostrum produced during each feeding is appropriate for the size of the newborn's stomach and is sufficient, calorically, for feeding a newborn during the first few days of life. Produced during pregnancy and the first days after childbirth, colostrum is rich in protein and Vitamins A, B12 and K, which support infants' growth, brain development, vision, immune systems, red blood cells, and clotting cascade. The breast milk also has long-chain polyunsaturated fatty acids which help with normal retinal and neural development. The caloric content of colostrum is about 54 Calories/100mL. The second type of milk is transitional milk, which is produced during the transition from colostrum to mature breast milk. As the breast milk matures over several weeks, the protein content decreases on average.
== Binding specificity == The effects of a drug are a result of their binding selectivity with macromolecule properties of an organism, or the affinity with which different ligands bind to a substrate. More specifically, the specificity and selectivity of a ligand to its respective receptor provides researchers the opportunity to isolate and produce specific drug effects through the manipulation of ligand concentrations and receptor densities. Hormones and neurotransmitters are essential endogenous regulatory ligands that affect physiological receptors within an organism. Drugs that act upon these receptors are incredibly selective in order to produce required responses from signaling molecules. Specific binding refers to the binding of a ligand to a receptor, and it is possible that there is more than one specific binding site for one ligand. Non specific binding refers to the binding of a ligand to something other than its designated receptor such as various other receptors, or different types of transporters in the cell membrane. For example, various antagonists can bind to multiple types receptors. In the case of muscarinic antagonists, they can also bind to histamine receptors. Such binding patterns are technically considered specific, as the destination of the ligand is specific to multiple receptors. However, researchers may not be focused on such behaviors compared to other binding factors. Nevertheless, nonspecific binding behavior is very important information to acquire.
Sources: en.wikipedia.org
The "grafting from" technique involves the generation of radicals along the polymer backbone from an abstraction of a halogen, from either the backbone or a functional group along the backbone. Monomers are reacted with the radicals along the backbone and subsequently generate polymers which are grafted from the backbone of the first polymer. The schematic for "grafting to" shows an example using anionic polymerizations, the polymer containing the carbonyl functionalities gets attacked by the activated polymer chain and generates a polymer attached to the associated carbon along with an alcohol group, in this example. These examples show us the potential of fine tuning end groups of polymer chains to target certain copolymer structures.
NADH dehydrogenase is an enzyme that converts nicotinamide adenine dinucleotide (NAD) from its reduced form (NADH) to its oxidized form (NAD+). Members of the NADH dehydrogenase family and analogues are commonly systematically named using the format NADH:acceptor oxidoreductase. The chemical reaction these enzymes catalyze is generally represented with the following equation:
=== 1950s === 1950: Isabella Abbott became the first Native Hawaiian woman to receive a PhD in any science; hers was in botany. 1950: Esther Lederberg was the first to isolate lambda bacteriophage, a DNA virus, from Escherichia coli K-12. 1952: Grace Hopper completed what is considered to be the first compiler, a program that allows a computer user to use English-like words instead of numbers. It was known as the A-0 compiler. 1956: The Wu experiment was a nuclear physics experiment conducted in 1956 by the physicist Chien-Shiung Wu, born in China but having become an American citizen in 1954, in collaboration with the Low Temperature Group of the US National Bureau of Standards. That experiment showed that parity could be violated in weak interaction.
Sources: en.wikipedia.org
It is described as a synthetic analogue of the ACTH(4–10) fragment, a short segment of adrenocorticotropic hormone. Its sequence differs from that fragment and includes two proline residues, which influence stability and behaviour in solution.
It appears in Russian pharmaceutical listings as a nasal formulation, but it is not an authorised medicine in the United States or the European Union. Outside those markets it is normally encountered as a research chemical rather than a prescription product.
Laboratory and animal work points to melanocortin signalling and changes in neurotrophic factor levels, especially brain-derived neurotrophic factor. The exact receptor targets and the degree to which these findings transfer to humans are still unresolved.
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.