A practical reference on ACTH analog: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-12-23. Anything still debated is marked as such rather than presented as settled.
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.
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.
从分子层面看，Semax 是线性七肽，没有二硫键、糖基或脂链修饰，N 端为游离氨基，C 端为游离羧基。分子含组氨酸与谷氨酸侧链，因此在水和甲醇等极性溶剂中溶解良好，在非极性溶剂中溶解有限。计算分子量约为 814 Da，与其质子化离子的质荷比吻合，可用于质谱确认。
稳定性主要由水解与氧化两条路径支配。肽键在中性或弱酸性条件下相对稳定，遇到强碱或长时间高温则明显断裂；甲硫氨酸侧链容易被氧化成亚砜，使主峰前移并拉低实际含量。金属离子、光照和反复冻融会进一步促进降解或聚集。冻干粉在低温避光条件下可存放较长时间，配制后的水溶液通常需要冷藏并尽快用完。
纯度评估以反相高效液相色谱为主，通过主峰面积百分比给出粗略结果，再配合电喷雾质谱核对分子量。氨基酸分析可验证组成比例，手性色谱或毛细管电泳用于检查残基构型。常见杂质包括缺失序列的短肽、氧化产物与二聚体。由于多数市售品不附带完整检验报告，独立第三方检测常被用来核实标称值。
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic heptapeptide | Analog of an ACTH fragment |
| Amino acid length | Seven residues | Met-Glu-His-Phe-Pro-Gly-Pro |
| Origin | Moscow, 1980s | Institute of Molecular Genetics |
| Approved regions | Russia and some neighboring states | Not cleared in Western markets |
| Common trade names | Multiple national brands | Sold as a nasal formulation |
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.
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.
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.
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.
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.
=== Others === Jessamine Lovelace — the ghost guardian of the London Institute. Also known as Jessamine Gray after her secret marriage to Tessa's brother Nate in The Infernal Devices. Jesse Blackthorn — Tatiana's deceased son and Grace Blackthorn's adoptive brother. His spirit can only be seen by his mother, Grace, and Lucie.
==== Denervation supersensitivity ==== When the innervation to Substance P nerve terminals is lost, post-synaptic cells compensate for the loss of adequate neurotransmitter by increasing the expression of post-synaptic receptors. This, ultimately, leads to a condition known as denervation supersensitivity as the post-synaptic nerves will become hypersensitive to any release of Substance P into the synaptic cleft.
I cannot remember how they first came to be offered to us. But they were distributed in the dressing rooms. We didn't have to take them but most of the players did. The tablets were mostly white but once or twice they were yellow. They were used through the 1961–62 season and the championship season which followed it. Drug-taking had previously been virtually unnamed in the club. But once it had started we could have as many tablets as we liked. On match days they were handed out to most players as a matter of course. Soon some of the players could not do without the drugs. The club agreed that drugs had been used but that they "could not possibly have had any harmful effect." Dunlop, however, said he had become an addict. In November 1942, the Italian cyclist Fausto Coppi took "seven packets of amphetamine" to beat the world hour record on the track. In 1960, the Danish rider Knud Enemark Jensen collapsed during the 100 km team time trial at the Olympic Games in Rome and died later in hospital. The autopsy showed he had taken amphetamine and another drug, Ronicol, which dilates the blood vessels. The chairman of the Dutch cycling federation, Piet van Dijk, said of Rome that "dope – whole cartloads – [were] used in such royal quantities." The 1950s British cycling professional Jock Andrews would joke: "You need never go off-course chasing the peloton in a big race – just follow the trail of empty syringes and dope wrappers." The Dutch cycling team manager Kees Pellenaars told of a rider in his care:
Sources: en.wikipedia.org
=== First confirmed cases: May–June 2022 === On 12 May 2022, the North Korean government declared a "severe national emergency", after samples from an unspecified number of people tested positive for COVID-19. This marked the first time that North Korea had publicly acknowledged the existence of COVID-19 cases in the country. The Korean Central News Agency stated that Supreme Leader Kim Jong Un had called an emergency meeting of the Politburo of the Workers' Party of Korea after learning of the samples, which were sourced from residents of Pyongyang and had symptoms "consistent with" the Omicron variant. The Politburo recommended the implementation of a "maximum" emergency quarantine, to include nationwide lockdowns, border restrictions, and restrictions on group sizes in workplaces. During the politburo meeting, the previous anti-pandemic strategy was criticised. NK News reported that the entire country had been placed under a lockdown two days prior, though farmers in border regions close to South Korea were seen still tending the fields. It was later reported by state media that at least one North Korean died after testing positive, and that 187,800 people are now under quarantine due to "fever". On 13 May, Kim Jong Un held a meeting at the State Emergency Epidemic Prevention Headquarters, where he called for further anti-pandemic work, lockdowns, and isolation of suspected cases. The effort to stop the spread was declared to be a supreme task of the party.
=== Taste and odor === Pure water is usually described as tasteless and odorless, although humans have specific sensors that can feel the presence of water in their mouths, and frogs are known to be able to smell it. However, water from ordinary sources (including mineral water) usually has many dissolved substances that may give it varying tastes and odors. Humans and other animals have developed senses that enable them to evaluate the potability of water to avoid water that is too salty or putrid.
=== Artificial pancreas === There has also been substantial effort to develop a fully automated insulin delivery system or "artificial pancreas" that could sense glucose levels and inject appropriate insulin without conscious input from the user. Current "hybrid closed-loop systems" use a continuous glucose monitor to sense blood sugar levels, and a subcutaneous insulin pump to deliver insulin; however, due to the delay between insulin injection and its action, current systems require the user to initiate insulin before taking meals. Several improvements to these systems are currently undergoing clinical trials in humans, including a dual-hormone system that injects glucagon in addition to insulin, and an implantable device that injects insulin intraperitoneally where it can be absorbed more quickly.
Sources: en.wikipedia.org
It originated at the Institute of Molecular Genetics in Moscow during the 1980s. The work was carried out by a Russian research group that specialized in peptide neuropharmacology.
It is registered as a medicine in Russia and has been used clinically there for decades. No regulatory agency in Western Europe or North America has approved it for any indication.
Semax corresponds to the four-to-ten fragment of adrenocorticotropic hormone. Because it omits the first three residues, it lacks the adrenal-stimulating action of the full hormone.
电喷雾或基质辅助激光解吸电离质谱是常用手段，测得的质子化离子质荷比可换算为分子量。结果与理论值落在合理误差内，才支持结构一致的判断。