N-acetyl Semax is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2026-01-15. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Practical handling follows from those properties. Bulk material is best divided into single-use portions soon after receipt, because each thaw exposes the whole container to moisture and temperature cycling. Vials should be allowed to reach room temperature before opening to prevent condensation on the powder. Low-binding plasticware reduces loss of dilute solutions, and sterile filtration is used when a preparation must remain free of microbial growth. Records of batch number, reconstitution date and storage history are what allow a later analytical result to be interpreted meaningfully.
Identity and purity of Semax are established mainly by reversed-phase high-performance liquid chromatography coupled with mass spectrometry. The chromatographic trace gives a purity estimate as a percentage of total peak area, while electrospray or matrix-assisted laser desorption ionization confirms the molecular mass against the calculated value. Amino acid analysis and sequence-specific fragmentation provide further confirmation when a supplier's chain of custody is unclear. Vendors frequently quote a purity figure without stating the detection wavelength or the integration method, which limits how far one number can be compared with another.
| 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 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.
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.
Solid material is normally kept at minus 20 degrees Celsius in a sealed, desiccated container. Reconstituted solutions are less stable and are usually divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are avoided because they promote aggregation and loss of activity. Light exposure is minimized by using amber glassware or foil wrapping. Published stability data for this peptide are sparse, so recommended storage conditions rest mainly on general practice for short synthetic peptides rather than on dedicated study.
Identity and purity are commonly assessed by reversed-phase high-performance liquid chromatography, with ultraviolet detection near 214 nanometers for the peptide backbone. Mass spectrometry, either electrospray or matrix-assisted laser desorption, confirms molecular mass and detects truncation or modification products. Amino acid analysis can verify composition. Because the sequence contains no strongly absorbing aromatic residue apart from phenylalanine, detection wavelengths are chosen carefully. Purity values above 95 percent are typical for research-grade material.
各国监管态度分化明显。俄罗斯按处方药管理，部分东欧国家留有使用记录；欧盟与美国未批准其作为药物上市，市面流通品通常标注为研究用化学品。身份差异意味着标示含量、纯度与无菌性缺少统一核查。体育领域还牵涉反兴奋剂名录，跨境携带则受目的地药品法规约束。
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。
Published studies are dominated by animal models of stroke, ischemia, and cognitive impairment, with a smaller number of human trials conducted in Russia. Many of the human reports are small, single-center, and published in Russian-language journals, which limits independent scrutiny. Outcome measures vary between studies and often rely on clinician-rated scales rather than objective biomarkers. Systematic reviews have noted the methodological weaknesses and called for larger, preregistered trials before firm conclusions can be drawn.
Claims about enhanced focus, memory, or mood in healthy people rest mostly on anecdotal reports and community discussion rather than on controlled data. It remains unclear whether any cognitive benefit observed in patients recovering from brain injury would extend to uninjured users. Dose-response relationships, long-term safety, and interactions with other drugs are not well characterized in the peer-reviewed literature. Questions about optimal route of administration and treatment duration likewise remain open.
Semax binds to melanocortin receptors and is thought to influence neuronal survival and plasticity rather than to act through the adrenal axis. Laboratory work has shown increased expression of brain-derived neurotrophic factor and nerve growth factor in treated tissue. Changes in c-Fos, a marker of neuronal activation, have also been reported. Because the peptide is rapidly degraded by peptidases, its effects are generally attributed to downstream signaling cascades rather than to sustained receptor occupancy.
=== Slow-release formulation === 5-HTP's short half-life is impractical for chronic drug therapy. Research conducted at Duke University in mice has demonstrated that 5-HTP when administered as slow-release appears to gain drug properties. Slow-release delivery attenuates or abolishes the peaks and valleys in 5-HTP exposure during treatment. Slow-release delivery of 5-HTP markedly improved the safety profile of 5-HTP and conferred stable plasma exposure of 5-HTP and strong and sustained enhancement of brain serotonin function. This discovery indicates that 5-HTP slow-release medications represent a new avenue for treatment of brain disorders responsive to serotonergic enhancement.
Hughes Helicopters was a major manufacturer of military and civilian helicopters from the 1950s to the 1980s. The company began in 1947, as a unit of Hughes Aircraft, then was part of the Hughes Tool Company after 1955. It became the Hughes Helicopter Division, Summa Corporation in 1972, and was reformed as Hughes Helicopters, Inc. in 1981. However, throughout its history, the company was informally known as "Hughes Helicopters". It was sold to McDonnell Douglas in 1984 and made a subsidiary under the name McDonnell Douglas Helicopter Systems, which was later renamed MD Helicopters when McDonnell Douglas merged with Boeing.
The prefix bi- (for joining of ring systems) is translated as 联 (lián, 'join', 'couple'), as in 联苯 for biphenyl. The stereochemical descriptors cis- and trans- are translated as 顺 (shùn, 'along') and 反 (fǎn, 'against'). The relational prefixes ortho-, meta-, and para- are translated as 邻 (lín, 'neighboring'), 间 (jiàn, 'between'), and 对 (duì, 'opposing'), respectively. The structural modification descriptors cyclo-, nor- and homo- are translated as 环 (huán, 'ring'), 降 (jiàng, 'lowered'), and 高 (gāo, 'high'). For example, norbornene is translated as 降冰片烯, in which the trivial name (冰片) for bornyl [literally, camphor] is used. When substitutive nomenclature is used for naming heterocycles, the suffix 杂 (zá, 'mixed') is used in the same way as '-a' in English (as in aza, thia, oxa, etc.). As an example, DABCO (1,4-diazabicylo[2.2.2]octane) is named 1,4-二氮杂二环［2.2.2］辛烷. The common unsaturated groups allyl and propargyl are translated as 烯丙(基) (xībǐng(jī), 'alkene-prop-(yl)') and 炔丙(基) (qūebǐng(jī), 'alkyne-prop-(yl)'). Thus, using 高 for homo- and 烯丙 for allyl, 3-buten-1-ol is also called 高烯丙醇 (i.e., homoallyl alcohol) in Chinese via semisystematic nomenclature. The Chinese Wikipedia page may be consulted for further details.
In 2019, the Economist Intelligence Unit's biannual Worldwide Cost of Living survey ranked Moscow 102nd among the 133 most expensive cities. ECA International's Cost of Living 2019 Survey ranked Moscow 120th among 482 locations globally.
Are, or think they may be, pregnant Have abnormal vaginal bleeding that has not been explained (controversial) Have untreated cervical or uterine cancer Have, or may have, breast cancer Have abnormalities of the cervix or uterus (controversial) Have had pelvic inflammatory disease within the past three months Have had an STI such as chlamydia or gonorrhea within the past three months Have liver disease or tumor Have an allergy to levonorgestrel or any of the inactive ingredients included in the device Insertion of an IUD is acceptable after a dilation and evacuation (D&E) abortion (second-trimester abortion), but may be associated with a higher expulsion rate. To reduce the risk of infection, insertion of an IUD is not recommended for women that have had a medical abortion but have not yet had an ultrasound to confirm that the abortion was complete, or that have not yet had their first menstruation following the medical abortion. A full list of contraindications can be found in the WHO Medical Eligibility Criteria for Contraceptive Use and the CDC United States Medical Eligibility Criteria for Contraceptive Use.
Sources: en.wikipedia.org
In vitro studies indicate gepotidacin can inhibit specific drug transporters, but the clinical significance of these findings requires further evaluation. Excretion is mainly fecal (~52%, 30% unchanged) and urinary (~31%, 20% unchanged), with the latter being the major route for absorbed drug. Renal impairment leads to elevated gepotidacin exposure, with the degree of increase directly linked to the severity of kidney dysfunction. This effect is particularly pronounced in patients with end-stage renal disease undergoing hemodialysis. Additionally, impaired kidney function decreases urinary excretion of the drug, which may necessitate dosage adjustments in severe cases to ensure safe and effective treatment. Severe hepatic impairment also elevates gepotidacin exposure, while moderate hepatic impairment did not show a clinically relevant effect during clinical trials.
=== Production === Aqueous humour is secreted into the posterior chamber by the ciliary body, specifically the non-pigmented epithelium of the ciliary body (pars plicata). 5 alpha-dihydrocortisol, an enzyme inhibited by 5-alpha reductase inhibitors, may be involved in production of aqueous humour.
== Hosts and disease development == Penicillium expansum has a wide host range, causing similar symptoms on fruits which include apples, pears, cherries, and citrus. Initial infection most often occurs at sites of fruit injury, such as bruises or puncture wounds. Although infections may start in the field, infected spots often become evident post-harvest, and expand while fruit is in storage. Infected areas are clearly delineated and light brown, and soft decaying tissue can be easily "scooped" out of the surrounding healthy tissue. Spore masses later appear on the surfaces of infected fruit, initially appearing as white mycelium, then turning blue to blue-green in color as the asexual spores mature. Fruit affected by P. expansum typically has an earthy, musty odor. Lesions measure 1–1.25 inches in diameter eight to ten weeks after infection if kept under cold storage conditions. Age factors into P. expansum infection, in that overripe or mature fruits are most susceptible to infection, while those picked underripe are less likely to become infected. In apples, the colors of the lesions may vary with variety, from lighter-brown on green and yellow apple varieties, to dark-brown on the deeper-red and other darker-color varieties. Varieties particularly susceptible to P. expansum infection include McIntosh, Golden Supreme, and Golden Delicious. Both sweet and sour cherries are affected by P. expansum. Cherry varieties found to be particularly susceptible to P. expansum infection were mainly early varieties, including Navalinda and Burlat.
=== Glutaminolysis and transamination === Aside from the citric acid cycle, α-ketoglutarate is made by glutaminolysis in which the enzyme glutaminase removes the amino group from glutamine to form glutamate which is converted to α-ketoglutarate by any one of three enzymes, glutamate dehydrogenase, alanine transaminase, or aspartate transaminase (see The glutaminolytic pathways). It is also made through the action of pyridoxal phosphate-dependent enzymes (alanine transaminase) in which glutamate is converted to α-Ketoglutarate by "donating" its −NH2 to other compounds (see transamination). These reactions are reversible. In the reverse direction of these reactions, α-ketoglutarate contributes to the production of amino acids such as glutamine, proline, arginine, and lysine as well as the lowering of cellular carbon and nitrogen (i.e., N) levels; this prevents excessive levels of these two potentially toxic elements from accumulating in cells and tissues. The neurotoxin, ammonia (i.e., NH3), is also prevented from accumulating in tissues. In this metabolic pathway the −NH2 group on an amino acid is transferred to α-ketoglutarate; this forms the α-keto acid of the original amino acid and the amine-containing product of α-ketoglutarate, glutamate. The cellular glutamate passes into the circulation and is taken up by the liver where it delivers its acquired −NH2 group to the urea cycle. In effect, the latter pathway removes excess ammonia from the body in the form of urinary urea.
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.
Suppliers normally quote a percentage of total chromatographic peak area, most often from reversed-phase HPLC. That figure says nothing about what the remaining percentage contains, and it depends on the detection wavelength used. A mass spectrometry result is a separate and stronger check on identity.