If you have been reading about intranasal delivery and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-05-28. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Stability depends heavily on physical state. Lyophilized powder held dry, cold and dark retains its content over long periods, whereas dissolved peptide begins to change within days at room temperature. The most cited degradation route is oxidation of the methionine residue, which converts the peptide to a sulfoxide form that elutes differently on chromatography. Hydrolysis of amide bonds and adsorption onto container walls contribute smaller losses. Buffers that exclude oxygen from the headspace slow the oxidation pathway, but no single condition prevents all change indefinitely.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White lyophilized powder | Typical for synthetic peptides |
| Solubility | Freely soluble in water | Also soluble in saline |
| Storage temperature | -20 C or below | Protect from repeated freeze-thaw |
| Analytical method | Reverse-phase HPLC | Confirms purity and identity |
| Common synonym | ACTH(4-10) analog | Reflects structural origin |
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.
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。
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。
The mechanisms attributed to semax are inferred from animal and cell studies rather than traced to one confirmed target. The most frequently cited pathway involves increased expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal and cortical tissue. Some work points to engagement of melanocortin receptors, particularly MC4, which the parent ACTH fragment can activate. Effects on dopaminergic and serotonergic signalling have also been reported. No single account explains all observed results, and the relative weight of each pathway remains unsettled.
Published studies examine a fairly narrow set of endpoints. Rodent experiments commonly measure maze learning, infarct volume after induced ischemia, and tissue levels of neurotrophic factors. Clinical reports from Russian centres describe attention, memory and recovery scores in patients after stroke or transient ischemic attack. Most of those human studies are small and few have been repeated by independent groups. Outcome measures differ between studies, which limits direct comparison.
Circulation time for the peptide is short because peptidases cleave it readily. The Pro-Gly-Pro tail is thought to slow breakdown compared with the bare ACTH fragment, but the gain appears modest. Absorption after intranasal dosing is limited, and only a fraction of a dose is expected to reach the central nervous system. Laboratory concentrations therefore sit well above levels achieved systemically, a gap that complicates translation from bench findings to clinical claims.
Identity and purity are confirmed with reversed-phase high-performance liquid chromatography, typically monitored at 214 nanometres where the peptide bond absorbs. Mass spectrometry, either electrospray or MALDI-TOF, verifies molecular mass against the theoretical value and detects truncation or adduct formation. Amino acid analysis and peptide mapping provide additional confirmation when required. The most frequently reported impurities are deletion sequences from incomplete coupling, methionine sulfoxide from oxidation, and dimeric species formed through non-covalent aggregation. Impurity profiles depend strongly on the synthesis and purification route chosen by the producer.
Published research has focused mainly on neurological and cognitive endpoints in animal models, with proposed mechanisms involving brain-derived neurotrophic factor and related signalling pathways. A substantial share of the human data originates from a limited number of research groups, and independent replication in other countries remains sparse. Regulatory status reflects that distribution: the peptide is registered as a medicine in Russia and appears in some neighbouring markets, while elsewhere it is handled as a research chemical without approved therapeutic labelling. Questions about dose-response relationships, long-term effects, and comparability across studies are still open.
Lyophilised powder is normally kept at -20 °C in a desiccated container, with some suppliers recommending -80 °C for long-term archival storage. Repeated freeze-thaw cycles are the most common cause of avoidable loss, so aliquoting before freezing reduces variability between working sessions. Dissolved peptide is far less stable than the dry solid and is usually prepared fresh or held briefly at 4 °C. Aqueous solutions support both hydrolysis of the backbone and oxidation of the N-terminal methionine, and these two routes dominate degradation under ordinary laboratory conditions.
== History == Symptoms of scurvy have been recorded in Ancient Egypt as early as 1550 BC. It was first reported amongst soldiers and sailors having inadequate access to fruits and vegetables which resulted in vitamin C deficiency. In Ancient Greece, the physician Hippocrates (460–370 BC) described symptoms of scurvy, specifically a "swelling and obstruction of the spleen." Pliny the Elder described sailors consuming sea kale to prevent scurvy in his Naturalis historia (77–79 AD). In 406 AD, the Chinese monk Faxian wrote that ginger was carried on Chinese ships to prevent scurvy. The knowledge that consuming certain foods is a cure for scurvy has been repeatedly forgotten and rediscovered into the early 20th century. Scurvy occurred during the Great Famine of Ireland in 1845 and also the American Civil War. In 2002, scurvy outbreaks were recorded in Afghanistan following the most intense phase of the war.
== Further reading == William P. Kirk "Krypton 85: a Review of the Literature and an Analysis of Radiation Hazards", Environmental Protection Agency, Office of Research and Monitoring, Washington (1972)
=== Microwave-assisted freeze dryers === Microwave-assisted freeze dryers utilize microwaves to allow for deeper penetration into the sample to expedite the sublimation and heating processes in freeze-drying. This method can be complicated to set up and run as the microwaves can create an electrical field capable of causing gases in the sample chamber to become plasma. This plasma could potentially burn the sample, so maintaining a microwave strength appropriate for the vacuum levels is imperative. The rate of sublimation in a product can affect the microwave impedance, in which power of the microwave must be changed accordingly.
=== Industrial synthesis === The industrial synthesis of pantothenic acid starts with the aldol condensation of isobutyraldehyde and formaldehyde. The resulting hydroxypivaldehyde is converted to its cyanohydrin derivative. which is cyclised to give racemic pantolactone. This sequence of reactions was first published in 1904.
Sources: en.wikipedia.org
=== Cognitive function === GH has also been studied in the context of cognitive function, including learning and memory. GH in humans appears to improve cognitive function and may be useful in the treatment of patients with cognitive impairment that is a result of GH deficiency.
==== American involvement ==== In the mid-2010s, the US identified China as a primary source of illicit fentanyl and other synthetic opioids. American anti-drug intervention regarding China is influenced and constrained by the geopolitical sensitivities of US-China relations. The US employs several approaches: exerting diplomatic pressure on China to impose internal controls on illicit drugs; seeking cooperation in US and international law enforcement efforts; unilaterally imposing targeted sanctions; and bringing criminal indictments against Chinese companies and individuals. The effectiveness of these approaches depends significantly on China's level of implementation and enforcement, which is directly related to the fluctuating state of overall US-China relations. Following China's scheduling of fentanyl-class substances in 2019, the flow of synthetic opioids from China to the US appeared to subside; trafficking from China shifted to precursor chemicals and related equipment, and Mexico's drug cartels emerged as major clients. In November 2023, President Biden announced an agreement with General Secretary Xi Jinping for China to crack down on the export of precursor chemicals and pill presses to the Western Hemisphere. A US House committee report released in April 2024 found companies making fentanyl precursors in China can still apply for Chinese state tax rebates and other financial benefits after exporting the product.
==== Secondary-Ion MS ==== SIMS is a micro-analytical technique valuable for three-dimensional analysis of a materials elemental composition and isotopic ratios. This method can be utilized in characterization of bulk materials with a detection limit in the low parts per billion (10−9 or ng/g) range. Particles as small as a few hundreds of nanometers can be detected. Ion production in this technique is dependent on the bombardment of solid samples with a focused beam of primary ions. The sputtered, secondary ions are directed onto the mass spectrometry system to be measured. The secondary ions are a result of kinetic energy transfer from the primary ions. These primary ions penetrate into the solid sample to some depth. This method can be used to detect any element, however the sputtering process is highly matrix dependent and ion yields vary. This method is especially useful, because it can be fully automated to find uranium particles in a sample of many million particles in a matter of hours. Particles of interest can then be imaged and further analyzed with very high isotopic precision.
Sources: en.wikipedia.org
== Career == After her PhD, Chutia continued her research at Dibrugarh University for another year as a CSIR-postdoctoral fellow. She entered the field of plasma physics at the Physical Research Laboratory in Ahmedabad and then joined the Institute for Plasma Research in Gandhinagar. She then returned to the Institute of Advanced Study in Science and Technology as a faculty member and set up the Plasma Physics Laboratory. After finishing a fellowship awarded by the Japanese government in 1988 to work at the Plasma Laboratory of the Institute of Space and Astronautical Science, Tokyo, in 2005 she became the director of the Institute of Advanced Study in Science and Technology.
Trails has seen several spin-offs and works in other types of media, including manga, audio dramas, and anime. Ys vs. Trails in the Sky is a crossover fighting game featuring characters from Trails and Falcom's Ys series. It was released exclusively in Japan in July 2010 but received an English fan translation patch in October 2021. The Legend of Nayuta: Boundless Trails was released in Japan in July 2012 and worldwide in 2023. It does not take place within Zemuria and also differs from the rest of the series by being an action role-playing game. The Legend of Heroes: Trails at Sunrise is a Japanese-only gacha game developed by UserJoy Technology. It was first released in 2016 as a browser game before being ported to other platforms. An original video animation adaptation of Trails in the Sky SC was produced by Kinema Citrus. Part one was released in November 2011 while the second was released in February 2012. They were licensed by Sentai Filmworks for release in North America that same year. A 12-episode anime series produced by Tatsunoko Production, The Legend of Heroes: Trails of Cold Steel – Northern War, aired in early 2023. A mobile game based on the anime was released in Japan in December 2023 and worldwide in May 2024. Several manga adaptations of games in the series have been released. Trails in the Sky also received a novelization. Other manga, such as The Legend of Heroes: Trails from Zero Pre-Story -The Ring of Judgment- and Trails in the Sky Gaiden: The Tale of Loewe, are original works that provide backstory to certain characters.
The tenets of Sikhism do not advocate a particular stance on either vegetarianism or the consumption of meat, but leave the decision of diet to the individual. The tenth guru, Guru Gobind Singh, however, prohibited "Amritdhari" Sikhs, or those that follow the Sikh Rehat Maryada (the Official Sikh Code of Conduct) from eating Kutha meat, or meat which has been obtained from animals which have been killed in a ritualistic way. This is understood to have been for the political reason of maintaining independence from the then-new Muslim hegemony, as Muslims largely adhere to the ritualistic halal diet. "Amritdharis" that belong to some Sikh sects (e.g. Akhand Kirtani Jatha, Damdami Taksal, Namdhari and Rarionwalay, etc.) are vehemently against the consumption of meat and eggs (though they do consume and encourage the consumption of milk, butter and cheese). This vegetarian stance has been traced back to the times of the British Raj, with the advent of many new Vaishnava converts. In response to the varying views on diet throughout the Sikh population, Sikh Gurus have sought to clarify the Sikh view on diet, stressing their preference only for simplicity of diet. Guru Nanak said that over-consumption of food (Lobh, Greed) involves a drain on the Earth's resources and thus on life. Passages from the Guru Granth Sahib (the holy book of Sikhs, also known as the Adi Granth) say that it is "foolish" to argue for the superiority of animal life, because though all life is related, only human life carries more importance: "Only fools argue whether to eat meat or not.
==== Antarctic plate ==== Marion hotspot (25) 46°54′S 37°36′E, w= 0.5 az= 080° ±12° Crozet hotspot (52) 46°06′S 50°12′E, w= 0.8 az= 109° ±10° rate= 25 ±13 mm/yr Possibly related to the Karoo-Ferrar geologic province (183 Ma) Kerguelen hotspot (20) 49°36′S 69°00′E, w= 0.2 az= 050° ±30° rate= 3 ±1 mm/yr Related to the Kerguelen Plateau (130 Ma) Heard hotspot (53), possibly part of Kerguelen hotspot 53°06′S 73°30′E, w= 0.2 az= 030° ±20° Île Saint-Paul and Île Amsterdam could be part of the Kerguelen hotspot trail (St. Paul is possibly not another hotspot) Balleny hotspot (2) 67°36′S 164°48′E, w= 0.2 az= 325° ±7° Erebus hotspot (54) 77°30′S 167°12′E
Sources: en.wikipedia.org
It is associated with the melanocortin receptor family, particularly subtypes found in the central nervous system. This interaction is separate from the adrenal pathway activated by full-length ACTH.
Peptidases degrade the compound within minutes in circulation. This short half-life is one reason nasal delivery is used, placing the substance close to the olfactory and trigeminal pathways.
No large multicenter trials have been published in English-language journals. The existing human evidence consists mainly of smaller studies conducted in Russia, which limits generalization.
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.