counterion 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 2026-03-24. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
Quality documentation for research-grade peptide usually includes a certificate of analysis stating purity, identity, and residual counterion content. Batch-to-batch variation in purity and salt form is a recognized issue, and comparisons across suppliers require attention to the exact counterion, for example acetate versus trifluoroacetate. Sequence verification by tandem mass spectrometry provides stronger evidence than a single mass measurement. For any study reporting biological results, the analytical method and the measured purity should be stated explicitly. Independent verification of supplier claims is considered good practice.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | ACTH(4-7) analogue |
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Free N terminus, unmodified side chains |
| Molecular weight | 813.9 Da | Free base; salt forms differ |
| Appearance | White to off-white powder | Lyophilised solid |
| Solubility | Freely soluble in water | Hydrophilic; polar solvents preferred |
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。
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.
== Uses == Traditional tribes such as the Orang Asli sell the flowers as a folk medicine. In laboratory rat experiments, extracts from the buds of this plant have shown potential in accelerating wound healing.
=== Gauge === The gauge of the chain is the thickness of the drive links, and is dictated by the gauge of the bar on which it is to be run. Usual gauges are 0.043, 0.050, 0.058, 0.063 and 0.080 inches (1.1, 1.3, 1.5, 1.6 and 2.0 mm). Chain and bar gauge must match; a chain that is too large will not fit, one that is too small will fall sideways and cut poorly.
Indigenous Americans in northern Peru also used bottle gourds as floats for fishing nets. Bulletproof vest – Ichcahuipilli, was a military armor used by various Mesoamerican cultures. It consisted of a layered cotton shirt, at least 2 inches thick, hardened with brine and other substances. It was originally intended to protect the wearer against projectiles and other weaponry, such as spears, arrows, and obsidian swords, but later was discovered to be capable of stopping musket shots. Bunk bed – the Iroquoian longhouses housed several families together. The concept of bunk beds was developed by these Native American peoples, since these longhouses included several bed combinations which featured one bed built on top of another, akin to bunk beds in modern times.
=== Other biosynthetic pathways === Carbamoyl phosphate is a carbamate mixed anhydride that is an intermediate in the urea cycle and the biosynthesis of pyrimidines. 5-carboxyamino-1-(5-phospho-D-ribosyl)imidazole (N5-CAIR), a carbamate derivative of aminoimidazole, is an intermediate in the biosynthesis of inosine. Both carbamates are produced via reaction of −NH2 groups with carboxyphosphate (HO−C(O)−OPO2−3).
Sources: en.wikipedia.org
=== 100% fruit juice === Research suggests that 100% fruit juice is not associated with an increased risk of diabetes. A 2018 review concluded that 100% fruit juice increases the risk of tooth decay in children, but there is "no conclusive evidence that consumption of 100% fruit juice has adverse health effects." A 2025 umbrella review concluded that "the balance of evidence does not support the exclusion of 100% juice from food-based guides to healthy eating".
Endocrine: Impotence, increased or decreased libido: gynecomastia in the male; breast enlargement and galactorrhea in the female; testicular swelling; elevation or depression of blood sugar levels. Other: Jaundice (simulating obstructive); altered liver function; parotid swelling; alopecia; flushing; weight gain or loss; urinary frequency, nocturia; perspiration.
== Beryllium-7 == Beryllium-7 is an isotope with a half-life of 53.22 days that is generated naturally as a cosmogenic nuclide. It is also a nuisance byproduct in nuclear reactors and accelerators. The rate at which the short-lived 7Be is transferred from the air to the ground is controlled in part by the weather. 7Be decay in the Sun (the half-life in stars can be greatly different from the normal as it is a free rather than a bound electron that is captured) is one of the sources of solar neutrinos, and the first type ever detected using the Homestake experiment. Presence of 7Be in sediments is often used to establish that they are fresh, i.e. less than about 3–4 months in age, or about two half-lives of 7Be.
Alpha particles were first described in the investigations of radioactivity by Ernest Rutherford in 1899, and by 1907 they were identified as He2+ ions. By 1928, George Gamow had solved the theory of alpha decay via tunneling. The alpha particle is trapped inside the nucleus by an attractive nuclear potential well and a repulsive electromagnetic potential barrier. Classically, it is forbidden to escape, but according to the (then) newly discovered principles of quantum mechanics, it has a tiny (but non-zero) probability of "tunneling" through the barrier and appearing on the other side to escape the nucleus. Gamow solved a model potential for the nucleus and derived, from first principles, a relationship between the half-life of the decay, and the energy of the emission, which had been previously discovered empirically and was known as the Geiger–Nuttall law.
. Stress intensity replaced strain energy release rate and a term called fracture toughness replaced surface weakness energy. Both of these terms are simply related to the energy terms that Griffith used:
Sources: en.wikipedia.org
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.
It contains the 4-7 fragment of adrenocorticotropic hormone extended at the C terminus. That truncation removes the region associated with steroidogenic activity. The design intent was to keep neurotrophic properties while avoiding full hormonal effects.
No natural source of the intact heptapeptide is known. It is produced by solid-phase peptide synthesis. Some related ACTH fragments arise as hormone processing products, but the Pro-Gly-Pro extension is a designed addition rather than a natural sequence.
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.