If you have been reading about lyophilized powder 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 2026-06-22. Where a claim depends on a specific study, the study is described rather than over-claimed.
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。
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 is supplied as a lyophilized powder that appears white to off-white. It dissolves readily in water, phosphate-buffered saline, and other aqueous media, which simplifies preparation of working solutions for laboratory use. The nasal products registered in Russia are dilute aqueous solutions, typically around 0.1 percent peptide by weight. Organic solvents are rarely necessary and can complicate handling. Because the peptide is hygroscopic, weighing should be performed quickly and with minimal exposure to ambient humidity.
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.
| Property | Value | Notes |
|---|---|---|
| 结构类别 | 线性合成七肽 | 无环化结构，不含二硫键 |
| 氨基酸序列 | Met-Glu-His-Phe-Pro-Gly-Pro | N 端为甲硫氨酸 |
| 分子量 | 约 814 Da | 游离碱形式的计算值 |
| 外观 | 白色至类白色粉末 | 具吸湿性 |
| 溶解性 | 易溶于水 | 亦可溶于甲醇等极性溶剂 |
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.
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.
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.
Narco News – news site focusing on drug war in Latin America Drug Policy Facts Major Studies of Drugs and Drug Policy Full text of major government commission reports on the drug laws from around the world over the last 100 years Historical Research on the Drug War Full text of numerous full histories of the drug war and thousands of original historical documents Cato Institute Drug Prohibition Research
=== Future coverage in health care plans === Randomized clinical trials of GLP-1 antagonists found that more than one-third of participants who were overweight or obese lost 20% or more of their weight. Due to substantial weight loss it is predicted that health care spending would decrease for people who are obese or overweight after taking GLP-1 antagonists to lose weight. This creates an incentive for health care plans and Medicare to include weight loss treatments.
=== Pharmacokinetics === Literature reviews have stated that fluvoxamine is metabolized primarily by CYP2D6 and to a minor extent by CYP1A2. However, CYP2D6 poor metabolizers do not have considerably higher fluvoxamine levels than extensive metabolizers. Fluvoxamine inhibits oxidative drug metabolising enzymes (particularly CYP1A2, and less potently CYP3A4 and CYP2D6) The mean plasma half-life of fluvoxamine after multiple oral doses of 100 mg/day in healthy, young volunteers was 13.6-15.6 hours. In the elderly, however the half life ranged from 17.4 to 25.9. Steady-state plasma fluvoxamine concentrations were 2-3 fold higher in children than in adolescents.
Sources: en.wikipedia.org
After the end of World War II, Enewetak came under the control of the United States as part of the Trust Territory of the Pacific Islands, until the independence of the Marshall Islands in 1986. During its tenure, the United States evacuated the local residents many times, often involuntarily. The atoll was used for nuclear testing, as part of the Pacific Proving Grounds. Before testing commenced, the U.S. exhumed the bodies of United States servicemen killed in the Battle of Enewetak and returned them to the United States to be re-buried by their families. Forty-three nuclear tests were fired at Enewetak from 1948 to 1958. The first hydrogen bomb test, code-named Ivy Mike, occurred in late 1952 as part of Operation Ivy; it vaporized the islet of Elugelab and created two new elements: Fermium and Einsteinium. This test included B-17 Flying Fortress drones to fly through the radioactive cloud to test onboard samples. B-17 mother ships controlled the drones while flying within visual distance of them. In all, 16 to 20 B-17s took part in this operation, of which half were controlling aircraft and half were drones. To examine the explosion clouds of the nuclear bombs in 1957/58, several rockets (mostly from rockoons) were launched. One USAF airman, Jimmy Robinson, was lost at sea during the tests. Robinson's F-84 Thunderjet crashed and sank 3.5 miles (5.6 km) short of the island. Robinson's body was never recovered.
== Biology / Functions == Efficient presentation of antigenic peptides by MHC class I molecules provides the key signal for adaptive immune responses by cytotoxic (CD8+) T lymphocytes. In the "endogenous" antigen presentation pathway, proteins synthesized by cells undergo cytosolic degradation and some of their peptide fragments are transported to the ER, where suitable-length peptides are loaded onto MHC class I molecules. In the ER, ERAP1 shortens longer peptides to the optimal length for stable binding onto MHC class I molecules (Figure 1). ERAP1, like other APP components, is induced by interferon gamma, a cytokine inducing antigen presentation. ERAP1 preferentially trims N-extended substrates of 9-16 residues to optimally sized 8-10 residue peptides. This "molecular ruler" mechanism is unique to ERAP1. ERAP1 also functions in the presentation of extracellular antigens in the cross-presentation pathway. ERAP1 "trimming" modulates the peptide repertoire presented by MHC class I molecules and thereby shapes the adaptive immune response. In murine models, ERAAP (the murine homologue of human ERAP1) deficiency results in a strong alteration and increased immunogenicity of the peptide repertoire presented by MHC-I. Murine models with genetic deficiency for ERAAP have been instrumental for understanding the role of peptide trimming in the ER. Besides peptide trimming in the ER, ERAP1 has been proposed to perform additional functions depending on its location.
In 1924, Louis de Broglie proposed that all particles—particularly subatomic particles such as electrons—have an associated wave. Erwin Schrödinger, fascinated by this idea, developed an equation that describes an electron as a wave function instead of a point. This approach predicted many of the spectral phenomena that Bohr's model failed to explain, but it was difficult to visualize, and faced opposition. One of its critics, Max Born, proposed instead that Schrödinger's wave function did not describe the physical extent of an electron (like a charge distribution in classical electromagnetism), but rather gave the probability that an electron would, when measured, be found at a particular point. This reconciled the ideas of wave-like and particle-like electrons: the behavior of an electron, or of any other subatomic entity, has both wave-like and particle-like aspects, and whether one aspect or the other is observed depend upon the experiment. Schrödinger's wave model for hydrogen replaced Bohr's circular orbits with atomic orbitals giving only the probability of finding an electron at positions around the nucleus. The orbitals come in a variety of shapes depending on their energy level and angular momentum. The shapes of atomic orbitals are found by solving the Schrödinger equation. Analytic solutions of the Schrödinger equation are known for the hydrogen atom and hydrogen-like atoms such as the hydrogen molecular ion. Beginning with the helium atom—which contains just two electrons—numerical methods are used to solve the Schrödinger equation.
Sources: en.wikipedia.org
== Contraindications and special caution == Benzodiazepines require special precaution if used in the elderly, during pregnancy, in children, alcohol or drug-dependent individuals and individuals with comorbid psychiatric disorders.
During 2020, as the COVID‑19 pandemic escalated globally and vaccine development intensified, the World Health Organization (WHO) COVAX facility adopted the motto "No one is safe unless everyone is safe" to emphasize the need for equitable vaccination. The facility set a goal of supplying COVID‑19 vaccines to nearly 100 low-to-middle income countries that could not afford them. COVAX sought to fundraise US$6.8 billion to purchase and deliver vaccines to participating countries in proportion to their populations. On 18 December 2020, the facility announced agreements with vaccine manufacturers to supply 1.3 billion doses for 92 low-middle income countries in the first half of 2021. Yet, by mid-December, some 16 countries representing only 14% of the world's population had preordered more than 10 billion vaccine doses or about 51% of the available world supply. Specifically, Canada, Australia, and Japan – having only 1% of the world's COVID‑19 cases – had collectively reserved some 1 billion vaccine doses, while the COVAX facility had reserved only a few hundred million doses. At the Group of Seven summit in June 2021, the United States promised to distribute 500 million vaccine doses internationally; this distribution began on 17 August. Preorders from rich countries were made during 2020 with 13 different vaccine manufacturers, whereas those for low-to-middle income countries were made primarily for the Oxford–AstraZeneca COVID-19 vaccine, which is lowest in cost and has no special refrigeration needs.
=== Negative effects === However, there are concerns regarding the role of movies in shaping the younger individual's perceptions of defining mental illness. Previous research regarding the film One Flew Over the Cuckoo's Nest (1975) with college students found that the portrayal of mental illness can negatively influence the individual's attitudes regarding individuals with mental illness, psychiatric institutions, and associated factors, leading to discrimination and general lack of opportunity for work, housing, and finding community for those experiencing mental illness. The public's misconception of certain mental illnesses poses a more significant threat than their negative opinions and judgments of those with issues with mental health. It may alter their ability to recognize signs and symptoms of certain mental illnesses in themselves or people they know if they are not consistent with the image they have come to know and recognize through media. Many people believe that the mental health content in mass media is checked by professionals for accuracy and, therefore, safe to believe and gather conclusions from. However, as many television shows do no such thing, people are led to believe inaccurate portrayals. Furthermore, mass media's depiction of mental illnesses causing violent or dangerous behavior may lead the public to believe that mentally ill people are more likely to harm others than in reality. This phenomenon can lead to the public being less likely to help or visit friends and family who are experiencing mental illness.
Sources: en.wikipedia.org
不存在。它是依据 ACTH 的一段序列人工设计的分子，天然蛋白质中找不到与之完全相同的七肽。名称属于研究代号，而非天然物质名。
Semax 对应 ACTH 第 4 至第 10 位的片段，并在两端做了替换与延长，使其不再具备促肾上腺皮质激素的典型内分泌活性。这一改动同时改变了它在体内的稳定性与分布特征。
俄罗斯将其列为处方药物，需要医生开具处方。多数其他国家把它当作研究化合物，不能作为药品销售或宣称疗效。具体合法性取决于当地法规。
Solid peptide is best kept frozen at about minus 20 degrees Celsius in a sealed container with desiccant. It should be allowed to reach room temperature before opening to prevent condensation. Repeated warming and cooling of the same vial is discouraged.