Everything below concerns ACTH(4-10). We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-08-01. Where a claim depends on a specific study, the study is described rather than over-claimed.
Pharmacokinetic accounts emphasize rapid breakdown. After intravenous dosing the intact peptide disappears from blood within minutes, and nasal delivery produces low but measurable concentrations. Metabolites rather than the parent molecule may account for part of the observed activity, although the relative contribution is unresolved. Dosing in the literature varies widely and no optimal schedule has been agreed. These gaps are regularly cited as a reason the findings have not produced broad clinical adoption beyond the original research setting.
Proposed mechanisms center on neurotrophic signaling rather than on classical melanocortin receptor activation. Rodent experiments have reported shifts in the expression of brain-derived neurotrophic factor and nerve growth factor after administration, together with changes in the associated receptor systems. Several authors argue that the peptide acts largely through its degradation products and their interaction with peptidergic pathways, but this remains a hypothesis rather than a settled finding. No single molecular target has been identified in a way that the field broadly accepts.
Published research covers ischemic stroke, traumatic brain injury, cognitive impairment, optic nerve conditions and attention-related measures. Much of the human evidence comes from small trials conducted in one country, which limits how far the results generalize. Animal models supply the larger share of the data, and effects seen in rodents do not transfer automatically to people. Reviews have noted that methodological reporting is often incomplete, making it difficult to pool results or compare treatment schedules across studies.
Terminology around the compound varies by source. It appears in catalogues and papers as Semax, as the heptapeptide ACTH(4-7)-Pro-Gly-Pro, and under various alphanumeric laboratory codes used by individual suppliers. These names refer to the same sequence but may imply different salt forms, purity grades, or counter-ions. Peptide databases usually list the free base mass, while product descriptions sometimes report acetate or trifluoroacetate salts with a different formula weight. Because naming conventions for research peptides are not standardised across vendors, checking the declared sequence and measured mass is more reliable than relying on a trade name alone.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its design combines the ACTH(4-7) core fragment with a C-terminal Pro-Gly-Pro extension, a modification intended to improve stability and prolong activity. The molecule is hydrophilic, carries no lipid chains or glycosylation, and has a theoretical mass just over 810 daltons in its free form. All seven residues are proteinogenic amino acids, so no non-natural building blocks appear in the backbone. A free N-terminal methionine and C-terminal proline define the unmodified parent peptide.
The compound was developed during the 1980s at the Institute of Molecular Genetics in Moscow as part of research on fragments of adrenocorticotropic hormone. Early work examined short ACTH-derived sequences that retained neurotrophic effects while lacking the endocrine activity of the full hormone. Semax entered clinical use in Russia during the 1990s, where it received registration for several neurological indications. Outside that region it remained primarily a laboratory research material rather than an approved therapeutic. English-language literature on it grew more slowly and frequently cited the original Russian studies.
| Property | Value | Notes |
|---|---|---|
| Primary research models | Rodent studies | Largest share of published data |
| Reported markers | BDNF and NGF expression | Measured mainly in animal tissue |
| Common administration | Intranasal | Matches the registered formulation |
| Blood residence time | Minutes | Rapid enzymatic degradation |
| Evidence quality | Small trials, limited replication | Noted repeatedly in reviews |
Material sold for laboratory use varies widely in stated purity and documentation. A certificate of analysis should list the analytical method, the column and detector used, and the observed purity value. Independent verification by an outside laboratory is the practical way to confirm identity when documentation is absent or internally inconsistent. Regulatory status differs by country, and a product legal in one jurisdiction may be unapproved or controlled in another.
Identity and purity of semax are established with reversed-phase high-performance liquid chromatography coupled to ultraviolet detection, usually at 214 nanometres. Mass spectrometry, most often electrospray ionisation in positive mode, confirms the molecular mass and reveals truncated sequences. Amino acid analysis and peptide mapping after enzymatic digestion provide additional structural confirmation. Laboratories typically report purity as the percentage area of the main peak, a figure that does not capture isomeric or oxidised variants unless the method resolves them.
The peptide is prone to several degradation pathways. Oxidation of the methionine residue produces a sulfoxide that elutes close to the parent peak in many chromatographic systems. Hydrolysis of peptide bonds and deamidation of susceptible residues in related sequences also reduce purity over time. Lyophilised material kept dry at minus twenty degrees Celsius and shielded from light is the most stable form commonly described in laboratory practice.
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.
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.
常规纯度与身份确认依赖反相高效液相色谱，并辅以质谱测定分子量。氨基酸组成分析可用于验证序列构成，肽图分析则能进一步定位修饰或降解产物。杂质谱通常关注缺失序列肽、截短片段和氧化产物。不同方法的检出限并不相同，因此各实验室报告的纯度数值不宜直接横向比较。
多数实验室与市售的 Semax 以冻干粉形式提供。冻干粉通常建议保存在 -20 °C 或更低温度下，同时避免光照与反复升温。短期运输有时采用冷藏条件，但长期保存仍以冷冻为主。分包操作应尽量减少开盖次数，以降低吸湿和微生物污染的风险。开封后若未一次用完，建议在干燥环境中密封并尽快放回低温储存。
溶液状态的稳定性明显低于冻干粉。肽类在水溶液中可能经历水解、氧化与聚集，其中甲硫氨酸和天冬酰胺等残基常是敏感位点。Semax 含有甲硫氨酸，因此氧化风险相对突出。工作液一般主张现配现用，或冷藏并在数日内用尽。缓冲液种类、pH 和离子强度都会影响降解速率，而关于最佳条件的公开数据并不统一。
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.
Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead as a research chemical.
Exponential amplification: At every cycle, the amount of product is doubled (assuming 100% reaction efficiency). After 30 cycles, a single copy of DNA can be increased up to 1,000,000,000 (one billion) copies. In a sense, then, the replication of a discrete strand of DNA is being manipulated in a tube under controlled conditions. The reaction is very sensitive: only minute quantities of DNA must be present. Leveling off stage: The reaction slows as the DNA polymerase loses activity and as consumption of reagents, such as dNTPs and primers, causes them to become more limited. Plateau: No more product accumulates due to exhaustion of reagents and enzyme.
== Tourism == The World Economic Forum's Travel & Tourism Competitiveness Index 2017 Report, ranked Thailand 34 of 136 nations (1=most competitive, 136=least competitive). Other ASEAN nations ranked were: Singapore, 6; Malaysia, 26; Indonesia, 42; Vietnam, 67; Philippines, 79; Laos, 94; Cambodia, 101. International Tourist Arrivals and Receipts: Thailand ranked number nine in 2016, with 32.5 million arrivals. It ranked third in international tourism receipts, US$49.9 billion. Global Destinations Cities Index 2016: In this seventh annual survey published by MasterCard, Bangkok ranked number one of 100 cities worldwide as the top global destination city as determined by number of visitors. It displaced London, the previous number one. Other ASEAN cities ranked in the survey were Singapore, 6; Ho Chi Minh City, 42; Hanoi, 52; Jakarta, 66; and Manila, 74. Travel and Tourism Competitiveness Report 2015: Thailand ranked 35 of 141 nations. Among ASEAN nations, Singapore was ranked 11; Malaysia, 25: Indonesia, 50; Philippines, 74; Vietnam, 75; Laos, 96; Cambodia, 105; and Myanmar, 134. International Tourist Arrivals: Thailand ranked number ten in 2013, up five places from 2012 with 26.5 million arrivals. International Tourist Receipts: Ranked number seven in the world in 2013, up two places from 2012, with receipts estimated at US$42.1 billion. Total tourism contribution to GDP: Thailand ranked 18 of 184 nations in 2014, with travel and tourism income totalling 2,345 billion baht or 19.3 percent of GDP.
== Uses == Purified water is suitable for many applications, including autoclaves, hand-pieces, laboratory testing, laser cutting, and automotive use. Purification removes contaminants that may interfere with processes, or leave residues on evaporation. Although water is generally considered to be a good electrical conductor—for example, domestic electrical systems are considered particularly hazardous to people if they may be in contact with wet surfaces—pure water is a poor conductor. The conductivity of water is measured in Siemens per meter (S/m). Sea-water is typically 5 S/m, drinking water is typically in the range of 5-50 mS/m, while highly purified water can be as low as 5.5 μS/m (0.055 μS/cm), a ratio of about 1,000,000:1,000:1. Purified water is used in the pharmaceutical industry. Water of this grade is widely used as a raw material, ingredient, and solvent in the processing, formulation, and manufacture of pharmaceutical products, active pharmaceutical ingredients (APIs) and intermediates, compendial articles, and analytical reagents. The microbiological content of the water is of importance and the water must be regularly monitored and tested to show that it remains within microbiological control. Purified water is also used in the commercial beverage industry as the primary ingredient of any given trademarked bottling formula, in order to maintain critical consistency of taste, clarity, and color. This guarantees the consumer reliably safe and satisfying drinking.
== History == “Synthesize a multi-component mixture of compounds in a single process and screen it also a single process”. This is the principle of combinatorial chemistry invented by Prof. Furka Á. (Eötvös Loránd University Budapest Hungary) in 1982, and described it including the method of synthesis of combinatorial libraries and that of a deconvolution strategy in a document notarized in the same year. Motivations that led to the invention had been published in 2002. DNA encoded chemical libraries (DECLs) are synthesized by the combinatorial chemistry principle and it clearly agrees with their application.
== Toxicity == Overdose is commonly broken into two categories – liver toxicity (from paracetamol poisoning) and dextropropoxyphene overdose. It may also account for mood- or thought-altering effects. An overdose of dextropropoxyphene may lead to various systemic effects. Excessive opioid receptor stimulation is responsible for the CNS depression, respiratory depression, aspiration pneumonia, miosis, and gastrointestinal effects seen in propoxyphene poisoning. In the presence of amphetamine, propoxyphene overdose increases CNS stimulation and may cause fatal convulsive seizures. In addition, both propoxyphene and its metabolite norpropoxyphene have local anesthetic effects at concentrations about 10 times those necessary for opioid effects. Norpropoxyphene is a more potent local anesthetic than propoxyphene, and they are both more potent than lidocaine. Local anesthetic activity appears to be responsible for the arrhythmias and cardiovascular depression seen in propoxyphene poisoning. Both propoxyphene and norpropoxyphene are potent blockers of cardiac membrane sodium channels, and are more potent than lidocaine, quinidine, and procainamide in this respect. As a result, propoxyphene and norpropoxyphene appear to have the characteristics of a Vaughn-Williams Class Ic antiarrhythmic. These direct cardiac effects include decreased heart rate (i.e. cardiovascular depression), decreased contractility, and decreased electrical conductivity (i.e., increased PR, AH, HV, and QRS intervals).
Sources: en.wikipedia.org
Later that month, during the final days before the United States fell off the "fiscal cliff", Biden's relationship with McConnell again proved important as the two negotiated a deal that led to the American Taxpayer Relief Act of 2012 being passed at the start of 2013.
== See also == International Journal of Pediatric Obesity Task Force on Childhood Obesity Classification of childhood obesity Obesity and the environment Social influences on fitness behavior Social stigma of obesity Sugary drink tax EPODE International Network Transport:
== Practical IR spectroscopy == The infrared spectrum of a sample is recorded by passing a beam of infrared light through the sample. When the frequency of the IR matches the vibrational frequency of a bond or collection of bonds, absorption occurs. Examination of the transmitted light reveals how much energy was absorbed at each frequency (or wavelength). This measurement can be achieved by scanning the wavelength range using a monochromator. Alternatively, the entire wavelength range is measured using a Fourier transform instrument and then a transmittance or absorbance spectrum is extracted. This technique is commonly used for analyzing samples with covalent bonds. The number of bands roughly correlates with symmetry and molecular complexity. A variety of devices are used to hold the sample in the path of the IR beam These devices are selected on the basis of their transparency in the region of interest and their resilience toward the sample.
== Growth == The growth amidst whitefish species can be altered due to intraspecific competition. Fish populations such as Vendace and Roach share zooplankton for food which is crucial for young populations of whitefish. As this competition occurs, growth rate can be affected within multiple age groups or at an older age.
The two substrates of this enzyme are S-(hydroxymethyl)glutathione and oxidised nicotinamide adenine dinucleotide (NAD+). Its products are S-formylglutathione, reduced NADH, and a proton. The enzyme can also use the alternative cofactor, nicotinamide adenine dinucleotide phosphate. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is S-(hydroxymethyl)glutathione:NAD+ oxidoreductase. Other names in common use include NAD-linked formaldehyde dehydrogenase (incorrect), formaldehyde dehydrogenase (incorrect), formic dehydrogenase (incorrect), class III alcohol dehydrogenase, ADH3, &chi, -ADH, FDH (incorrect), formaldehyde dehydrogenase (glutathione) (incorrect), GS-FDH (incorrect), glutathione-dependent formaldehyde dehydrogenase (incorrect), NAD-dependent formaldehyde dehydrogenase, GD-FALDH, and NAD- and glutathione-dependent formaldehyde dehydrogenase. This enzyme participates in methane metabolism.
Sources: en.wikipedia.org
The main proposal is modulation of neurotrophic factors such as brain-derived neurotrophic factor, supported largely by animal experiments. Receptor-level targets have not been firmly established. Most reviews describe the mechanism as only partially characterized.
The compound is registered as a medicine in Russia, so clinical work has concentrated there. Trials elsewhere are few and generally small. This geographic concentration is a recognized limitation in evidence reviews.
Some fraction may reach the central nervous system through olfactory pathways, and this is often cited as the rationale for the nasal route. The size of that fraction in humans is not well quantified. Blood concentrations after nasal dosing are low, which complicates measurement.
It is a synthetic seven-amino-acid peptide built from the ACTH(4-7) sequence plus a Pro-Gly-Pro tail. It belongs to the family of short ACTH fragments studied for nervous-system effects. Its backbone contains only standard amino acids.