neurotrophic factor 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 2026-01-02. Where a claim depends on a specific study, the study is described rather than over-claimed.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It corresponds to the ACTH(4-7) fragment extended at the C-terminus by a Pro-Gly-Pro tripeptide, an addition intended to slow enzymatic breakdown. The molecular formula is C37H51N9O10S and the molecular mass is approximately 814 daltons. In the literature it is often described as an ACTH(4-10) analog, although that label reflects a naming convention as much as a precise structural relationship. The compound was developed in Russia and remains most closely associated with that research tradition.
Laboratory descriptions of the material are consistent across suppliers. It appears as a white to off-white lyophilized powder that dissolves readily in water and in polar organic solvents such as dimethyl sulfoxide. Aqueous solutions are clear and colorless at low concentrations. Because the peptide contains methionine, oxidation at the sulfur atom is a recognized degradation pathway, and handling notes usually call for protected, desiccated storage. Reported purity for research-grade lots is generally above 95 percent as measured by reversed-phase high-performance liquid chromatography.
Development of the compound took place in the Soviet Union during the 1980s, largely through peptide research groups affiliated with the Shemyakin-Ovchinnikov Institute and Moscow State University. Investigators screened fragments of adrenocorticotropic hormone for activity on the central nervous system while attempting to separate cognitive effects from hormonal ones. The shortened sequence was selected because it retained behavioral activity in animal models without stimulating corticosteroid release. Early publications described the molecule as an ACTH(4-10) analog.
Published research on this peptide originates mainly from Russian laboratories, and the wider international literature is comparatively thin. Studies have used rodent models of stroke, hypoxia, and memory tasks, with a smaller number of human trials reported. Reported outcomes include changes in attention and memory measures, along with effects on neurotrophic factor expression in some experiments. Small sample sizes, inconsistent dosing protocols, and limited independent replication are widely noted limitations, so the strength of the clinical evidence remains an open question.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Contains one methionine sulfur atom |
| Molecular mass | Approximately 814 Da | Consistent with a seven-residue peptide |
| Appearance | White to off-white powder | Typical lyophilized form |
| Solubility | Freely soluble in water | Also soluble in dimethyl sulfoxide |
| Typical storage | -20 °C, desiccated | Limits methionine oxidation |
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.
Development took place during the 1980s at institutes of the Russian Academy of Sciences, where peptide fragments of ACTH were screened for cognitive and neuroprotective effects. The compound received regulatory approval in Russia as a nasal preparation, marketed for conditions such as ischemic stroke, transient ischemic attacks, and optic nerve disorders. Registration in other countries has not followed. Most published clinical reports originate from a small number of Russian research groups, and independent replication outside that setting remains limited. The regulatory status therefore differs sharply between Russia and the rest of the world.
Laboratory work points toward modulation of neurotrophic signaling, particularly expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal tissue. Studies also describe effects on monoamine turnover, inflammatory mediators, and oxidative markers. These observations come mainly from animal models and cultured cells, so the causal chain in humans is not firmly established. Whether the reported molecular changes translate into measurable clinical benefit is an open question. Reviews generally present the mechanism as plausible rather than demonstrated.
The McDLT was a hamburger sold by the fast-food restaurant chain McDonald's from 1984 to 1991. The product's marketing focused on keeping the hot and cold components separate until the customer assembled them, popularized by the slogan "Keep the hot side hot, and the cool side cool." McDonald's discontinued the sandwich in early 1991, citing complaints about its bulky polystyrene packaging, which caused logistical difficulties in restaurant kitchens and environmental concerns. Later accounts have described the McDLT as a failed McDonald's product.
an identified market; and, a certain rate of consumption (demand) to maintain profit and outweigh perceived risks. Under these conditions competition is discouraged, ensuring criminal monopolies sustain profits. Legal substitution of goods or services may (by increasing competition) force the dynamic of organized criminal operations to adjust, as will deterrence measures (reducing demand), and the restriction of resources (controlling the ability to supply or produce to supply).
== Distribution and habitat == R. hasseltii can only be found on several locations in Kerinci Seblat National Park, Sumatra, Indonesia, and Peninsular Malaysia, including Taman Negara and Temengor Forest Reserve. The type locality of the species in what is now West Sumatra, where it was first described, had gone extinct as a result of local plantation expansion. This plant is entirely dependent on host species from the genus Tetrastigma.
== Development == Developed as a next generation aptamer technology, Optimer ligands were produced to improve the performance, manufacturability, and commercialisation of aptamers. Optimer ligands are selected via an automated, high throughput in vitro screening process. 3 distinct discovery platforms are integrated into the Optimer platform for optimized discovery according to target type. Starting from a diverse library of potential nucleic acid binders, the Optimer library is refined and enriched for sequences that have the required binding characteristics including affinity, specificity, cross reactivity, and buffer compatibility. The enriched Optimer population is subsequently screened to identify the best performing Optimer ligand sequence. Following selection of the appropriate sequence the identified Optimer undergoes a process to determine the minimum oligonucleotide fragment within this sequence that possesses the correct target-binding characteristics. The Optimer is trimmed to contain only this sequence, removing additional free non-target binding nucleotide bases. This reduces the molecular weight of the Optimer from 29 kDa to 5 kDa and increases the stability of the molecule through a reduction in entropy, as additional motion of the free nucleotides is removed.
Sources: en.wikipedia.org
=== Whipple's triad === The symptoms of low blood sugar alone are not specific enough to characterize a hypoglycemic episode. A single blood sugar reading below 70 mg/dL is also not specific enough to characterize a hypoglycemic episode. Whipple's triad is a set of three conditions that need to be met to accurately characterize a hypoglycemic episode. The three conditions are the following:
After having tried for a long time to make bread with potatoes, Antoine Parmentier understood that this tuber should be considered as a versatile vegetable, and that its use required the popularization of recipes that would make it a main food. In his Examen chymique des pommes de terre published in 1773, he cites (but without giving the precise date) the composition of a menu that he had served to friends:
=== Statehood era === The U.S. conducted underground tests of nuclear weapons on Amchitka Island from 1965 to 1971 as part of the Vela Uniform program. The final detonation, the Cannikin, was the largest underground nuclear explosion by the U.S. The Alaska Native Claims Settlement Act became law in 1971. In 1977, the Ounalashka Corporation (from Unalaska) declared a dividend. This was the first village corporation to declare and pay a dividend to its shareholders. The Aleutian Islands were designated a UNESCO biosphere reserve in 1976. The Aleutians were one of 17 biosphere reserves in the United States withdrawn by request of the U.S. government from the programme in June 2017.
=== Chemical precursor === Castor oil can react with other materials to produce other chemical compounds that have numerous applications. Transesterification followed by steam cracking gives undecylenic acid, a precursor to specialized polymer nylon 11, and heptanal, a component in fragrances. Breakdown of castor oil in strong base gives 2-octanol, both a fragrance component and a specialized solvent, and the dicarboxylic acid sebacic acid. Hydrogenation of castor oil saturates the alkenes, giving a waxy lubricant. Castor oil may be epoxidized by reacting the OH groups with epichlorohydrin to make the triglycidyl ether of castor oil which is useful in epoxy technology. This is available commercially as Heloxy 505. The production of lithium grease consumes a significant amount of castor oil. Hydrogenation of castor oil yields 12-hydroxystearic acid, a precursor to lithium 12-hydroxystearate, a thickener in lubricating greases. Since it has a relatively high dielectric constant (4.7), highly refined and dried castor oil is sometimes used as a dielectric fluid within high-performance, high-voltage capacitors.
These early experiments with animal blood provoked a heated controversy in Britain and France. Finally, in 1668, the Royal Society and the French government both banned the procedure. The Vatican condemned these experiments in 1670. Blood transfusions fell into obscurity for the next 150 years.
Sources: en.wikipedia.org
It is registered as a pharmaceutical product in Russia, where it is typically supplied as a nasal solution. In most other countries it is not an approved drug and is traded as a research chemical instead. Approval status depends entirely on the jurisdiction involved.
Most published work uses intranasal administration, matching the route of the registered Russian formulation. Some animal experiments use intravenous or intraperitoneal injection. The route matters because the intact peptide is cleared rapidly from blood, so exposure differs between methods.
A purity value describes the share of the powder accounted for by the target peptide, usually by high-performance liquid chromatography. It does not confirm that the sequence is correct, which requires mass spectrometry or amino acid analysis. Purity and identity are separate checks.
It is a synthetic peptide of seven amino acids. Its backbone corresponds to a fragment of adrenocorticotropic hormone extended at the carboxyl end. The material is distributed as a lyophilized solid for laboratory use.