If you have been reading about Heptapeptide 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.
Updated 2026-08-01. Numbers and descriptions here follow the published literature rather than marketing material.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. The first four residues correspond to the ACTH(4-10) fragment, while the terminal Pro-Gly-Pro extension was added to improve metabolic stability. Its molecular formula is C37H51N9O10S and its monoisotopic mass is approximately 813.9 Da. The compound is classified as a peptide research chemical and as a registered pharmaceutical product in Russia, but it does not hold marketing approval in the European Union or the United States. Naming conventions vary across supplier catalogs.
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.
The C-terminal Pro-Gly-Pro extension is not incidental. Proline-rich tails are known to resist several common peptidases, and the published literature attributes the longer half-life of Semax, relative to unmodified ACTH fragments, to this feature. The modification also removes the melanocyte-stimulating and corticosteroidogenic activity that characterizes longer ACTH-derived sequences. Because the molecule is small and hydrophilic, it is typically formulated as an aqueous solution for intranasal or parenteral delivery. Acetylation or amidation at the termini appears in closely related research peptides and shifts the mass by a fixed increment.
Reported pharmacological work centers on neurotrophic signaling, including changes in BDNF and NGF expression in hippocampal tissue in animal models. Human data come largely from studies conducted in Russia, and how well those results generalize to other populations remains an open question. Regulatory status differs sharply by jurisdiction: Semax is a registered prescription medicine in Russia, while it holds no approved marketing status in the United States or the European Union. Outside such jurisdictions it is generally handled as a research chemical, which affects both documentation and quality expectations.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Seven-residue peptide |
| Molecular mass | 813.9 Da | Monoisotopic value |
| Appearance | White to off-white powder | Lyophilized form |
| Solubility | Freely soluble in water | Also soluble in saline and polar solvents |
| Storage (dry) | -20 °C or lower | Desiccated, protected from light |
Pharmacological accounts link semax to melanocortin signalling and to modulation of neurotrophic factor expression, particularly brain-derived neurotrophic factor and nerve growth factor. Much of this evidence comes from rodent studies using intranasal delivery, a route chosen because it allows peptides to reach the central nervous system with limited systemic exposure. Whether the same mechanisms operate in humans at comparable magnitude remains an open question. The precise receptor or receptors responsible for the reported behavioural and neuroprotective effects have not been conclusively identified.
Clinical reports describe use in ischaemic stroke, transient ischaemic attack, optic nerve conditions, and cognitive complaints, but most of these studies are small and were conducted in a single region. Systematic reviews have generally described the evidence base as limited in size and variable in methodological quality. Randomised controlled data suitable for international regulatory assessment are scarce. As a result, major treatment guidelines outside Russia do not include the peptide, and interest in it remains largely research-driven rather than routine clinical.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It is described in the literature as an analogue of the ACTH(4–10) fragment, a short N-terminal portion of adrenocorticotropic hormone that retains some neurotropic activity without the full hormonal effects of the parent peptide. The molecule carries a methionine residue at the N-terminus and two proline residues near the C-terminus, features that shape both its interactions with receptor systems and its chemical stability. The free peptide corresponds to the formula C37H51N9O10S and a molecular mass near 813.9 Da.
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.
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.
In 1952, iproniazid, an antimycobacterial agent, was discovered to have psychoactive properties while researched as a possible treatment for tuberculosis. Researchers noted that patients given iproniazid became cheerful, more optimistic, and more physically active. Soon after its development, iproniazid and related substances were shown to slow enzymatic breakdown of serotonin, dopamine, and norepinephrine via inhibition of the enzyme monoamine oxidase. For this reason, this class of drugs became known as monoamine oxidase inhibitors, or MAOIs. During this time development of distinctively different antidepressant agents was also researched. Imipramine became the first clinically useful tricyclic antidepressant (TCA). Imipramine was found to affect numerous neurotransmitter systems and to block the reuptake of norepinephrine and serotonin from the synapse, therefore increasing the levels of these neurotransmitters. Use of MAOIs and TCAs gave major advances in treatment of depression but their use was limited by unpleasant side effects and significant safety and toxicity issues. Throughout the 1960s and 1970s, the catecholamine hypothesis of emotion and its relation to depression was of wide interest and that the decreased levels of certain neurotransmitters, such as norepinephrine, serotonin, and dopamine might play a role in the pathogenesis of depression. This led to the development of fluoxetine, the first SSRI.
== Chemical properties == Temozolomide is an imidazotetrazine derivative. It is slightly soluble in water and aqueous acids, and decomposes at 212 °C (414 °F). It was discovered in 2021 that temozolomide is an explosive, tentatively assigned as UN Class 1. Temozolomide has also been reported to be a comparatively safe and stable in situ source of diazomethane in organic synthesis. In particular, use as a methylating and cyclopropanating reagent has been demonstrated.
In July 2006, according to the New York Times, unpublished e-mails from FDA safety official David Graham argued telithromycin had not been proven safe, that safer drugs were available for the same indications, and that the approval was a mistake and should be immediately withdrawn. Between the start of telithromycin's marketing in mid-2004 and September 2006, there were 13 cases of liver failure, including at least four deaths, vision problems, blackouts, syncope, and potentially fatal cases of myasthenia gravis. The Times said that the FDA was embroiled in a "fierce battle" over the approval, fueled by exposure in the press. Senator Charles E. Grassley (R-Iowa, chairman, Senate Finance Committee), Representatives Edward J. Markey (D-Mass) and Henry A. Waxman (D-Calif) held hearings.
The exterior of an individual segment is a thin cuticle over the skin, commonly pigmented red to brown, which has specialized cells that secrete mucus over the cuticle to keep the body moist and ease movement through the soil. Under the skin is a layer of nerve tissue, and two layers of muscles—a thin outer layer of circular muscle, and a much thicker inner layer of longitudinal muscles. Interior to the muscle layer is a fluid-filled chamber called a coelom that by its pressurization provides structure to the worm's boneless body. The segments are separated from each other by septa (the plural of "septum") which are perforated transverse walls, allowing the coelomic fluid to pass between segments. A pair of structures called nephrostomes are located at the back of each septum; a nephric tubule leads from each nephrostome through the septum and into the following segment. This tubule then leads to the main body fluid filtering organ, the nephridium or metanephridium, which removes metabolic waste from the coelomic fluid and expels it through pores called nephridiopores on the worm's sides; usually, two nephridia (sometimes more) are found in most segments. At the centre of a worm is the digestive tract, which runs straight through from mouth to anus without coiling, and is flanked above and below by blood vessels (the dorsal blood vessel and the ventral blood vessel as well as a subneural blood vessel) and the ventral nerve cord, and is surrounded in each segment by a pair of pallial blood vessels that connect the dorsal to the subneural blood vessels.
Sources: en.wikipedia.org
== Physical characteristics == When first extracted from the pine cone, they are covered with a hard shell (seed coat), thin in some species and thick in others. The nutrition is stored in the embryo (sporophyte) in the center. Although a nut in the culinary sense, in the botanical sense, pine nuts are seeds; being a gymnosperm, they lack a carpel (fruit) outside. The shell must be removed before the pine nut can be eaten. Unshelled pine nuts have a long shelf life if kept dry and refrigerated (−5 to 2 °C or 23 to 36 °F); shelled nuts (and unshelled nuts in warm conditions) deteriorate rapidly, becoming rancid within a few weeks or even days in warm, humid conditions. Pine nuts are commercially available in the shelled form, but due to poor storage, they can have poor flavor and may already be rancid at the time of purchase. Consequently, pine nuts are often frozen to preserve their flavor. European pine nuts may be distinguished from Asian ones by their greater length than girth; Asian pine nuts are stubbier, shaped somewhat like long kernels of corn. The American piñon nuts are known for their large size and ease of shelling. In the United States, Pinus edulis, the hard shell of New Mexico and Colorado, became a sought-after species due to the trading post system and the Navajo people who used the nuts as a means of commerce. The Italian pine nut (P. pinea) was brought to the United States by immigrants and became a favored treat along the East Coast in the early 1930s, when bumper crops of American pine nuts were readily available at low prices.
== Prevention and management == Maintaining a healthy body weight and engaging in regular physical activity can help mitigate the risk of developing insulin resistance. The primary treatment for insulin resistance is exercise and weight loss. Both metformin and thiazolidinediones improve insulin sensitivity. Metformin is approved for prediabetes and type 2 diabetes and has become one of the more commonly prescribed medications for insulin resistance. The Diabetes Prevention Program (DPP) showed that exercise and diet were nearly twice as effective as metformin at reducing the risk of progressing to type 2 diabetes. However, the participants in the DPP trial regained about 40% of the weight that they had lost at the end of 2.8 years, resulting in a similar incidence of diabetes development in both the lifestyle intervention and the control arms of the trial. In epidemiological studies, higher levels of physical activity (more than 90 minutes per day) reduce the risk of diabetes by 28%. Furthermore, physical training has also generally been seen to be an effective antagonist of insulin resistance in obese or overweight children and adolescents (under the age of 19).
=== Metabolism === Melatonin is metabolized with an elimination half-life ranging from 20 to 50 minutes. The primary metabolic pathway transforms melatonin into 6-hydroxymelatonin, which is then conjugated with sulfate and excreted in urine as a waste product. It is primarily metabolized by the liver enzyme CYP1A2 and to a lesser extent by CYP1A1, CYP2C19, and CYP1B1.
==== Structure-based methods ==== Ideally, the structure of a drug target is known, which allows for structure-based pharmacophore modeling. A structure-based model integrates key structural properties of the protein's binding site, such as the spatial distribution of interaction points, with features identified from ligand based pharmacophore models to generate a holistic simulation of the ligand-protein interaction. A major challenge in structure-based modeling is to narrow down pharmacophore features, of which many are initially identified, to a set of high priority features, as modeling too many features is a computational challenge. Another challenge is the incompatibility of pharmacophore modeling with quantitative structure-activity relationship (QSAR) profiling. Accurate QSAR models rely on inclusion of many potential targets, not just the therapeutic target. For example, important pharmacophores may yield high-affinity interactions with therapeutic targets, but they may also lead to undesirable off-target activity, and they may also be substrates of metabolic enzymes, such as Cytochrome P450s. Therefore, pharmacophore modeling against therapeutic targets is only one component of the compound's total structure-activity relationship.
A molecular assembler, as defined by K. Eric Drexler, is a "proposed device able to guide chemical reactions by positioning reactive molecules with atomic precision". A molecular assembler is a molecular machine. Some biological molecules such as ribosomes fit this definition as biological machines. This is because they receive instructions from messenger RNA and then assemble specific sequences of amino acids to construct protein molecules.
Sources: en.wikipedia.org
Food and Drug Administration (FDA) New Dietary Ingredient (NDI) notification, evaluated under Australia's Therapeutic Goods Administration (TGA) ingredient framework, and is protected by multiple international patent applications related to banana peel extract and its applications.
== History == The first description of phenylalanine was made in 1879, when Schulze and Barbieri identified a compound with the empirical formula, C9H11NO2, in yellow lupine (Lupinus luteus) seedlings. In 1882, Erlenmeyer and Lipp first synthesized phenylalanine from phenylacetaldehyde, hydrogen cyanide, and ammonia. The genetic codon for phenylalanine was first discovered by J. Heinrich Matthaei and Marshall W. Nirenberg in 1961. They showed that by using mRNA to insert multiple uracil repeats into the genome of the bacterium E. coli, they could cause the bacterium to produce a polypeptide consisting solely of repeated phenylalanine amino acids. This discovery helped to establish the nature of the coding relationship that links information stored in genomic nucleic acid with protein expression in the living cell.
== External links == Antivenom Index, a joint project of the Association of Zoos and Aquariums and the American Association of Poison Control Centers which helps locate rare antivenoms Venom Response Program of the Miami-Dade Fire Rescue service
Guayaquileños are a thousand times get better" It is also denounced that he used to constantly insult Peruvians in private letters, accusing them of barbaric people for their lack of affection for republican ideas, in addition to admitting that he used to give false compliments to Peruvian politicians, to manipulate them so that they do not interfere with his Bolivian Federation project (in the largest project of the Great Homeland), as well as showing indifference to Corruption in Peru, or even encouraging it among the caudillos to weaken Peru (even seeking its total disarmament under the pretext financial insufficiency): "(...) The Empire [Federation of the Andes] will come true, or there will be a deluge of blood in America: therefore I entrust you with energy and perseverance. What do you have to fear from the imbeciles of Peru? Don't you already have the consent of Gamarra and La-Fuente? Aren't our friends the owners of the council of that cabinet, don't they have a majority in lodge 5, aren't they protected by our squad, and guaranteed by my power? Leave me alone with the plainsman Paez, and with these doctors from Bogotá; working well over there, I answer for the event. Meanwhile, that government destroys the liberals under the guise of anarchists. (...) When you see those pusillanimous Gamarra and La-Fuente look pale before the anarchists, ask them to take their cockade for a few days: when they fear too much, authorize them to take a million dollars divisibly from the Peruvian funds.
Sources: en.wikipedia.org
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.
The extension was introduced to slow enzymatic breakdown of the peptide in biological systems. Natural ACTH fragments are degraded rapidly by peptidases. Adding the tripeptide was intended to extend the window during which the molecule remains intact.
Most published work consists of animal experiments conducted in a small number of laboratories. Human data are limited in number and size. Whether the observed effects translate into reliable clinical benefit is still unresolved.
The sequence is Met-Glu-His-Phe-Pro-Gly-Pro, a seven-residue peptide. The first four residues correspond to the ACTH(4-10) fragment, and Pro-Gly-Pro is added at the C-terminus. N-acetylated versions also appear in the literature and differ in mass.