ACTH analog raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-07-25. Anything still debated is marked as such rather than presented as settled.
The parent fragment ACTH(4-10) carries the sequence Met-Glu-His-Phe-Arg-Trp-Gly. Semax replaces the arginine and tryptophan positions with a proline-glycine-proline tail, giving Met-Glu-His-Phe-Pro-Gly-Pro. That change removes residues associated with adrenal stimulation, so the peptide does not drive cortisol release the way full ACTH does. This distinction shapes how the compound is grouped in the literature, where it sits with neuropeptides and peptide neuromodulators rather than with corticosteroids.
Regulatory status varies sharply by country. Semax is registered for medical use in Russia, where it appears in formularies as a nasal solution, and it also holds registration in a small number of neighbouring states. It has no approval from the United States Food and Drug Administration or the European Medicines Agency, and it is not a scheduled controlled substance in most jurisdictions. Elsewhere it circulates mainly as laboratory material, so purity documentation comes from suppliers rather than from a national pharmacopoeia.
Semax is a synthetic peptide created in the Soviet Union during the early 1980s by researchers working in Moscow. It was built from the short adrenocorticotropic hormone fragment known as ACTH(4-10), and the chain was then extended with three additional amino acids. The resulting molecule was named semax and entered clinical use in Russia in 1994. It is generally described as a nootropic and neuroprotective agent rather than as a hormone analogue.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Analogue of the ACTH(4-10) fragment |
| Amino acid sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Single-letter form MEHFPGP |
| Molecular formula | C37H51N9O10S | Free peptide, nominal mass near 814 Da |
| First registration | 1994, Russia | Nasal formulation for neurological indications |
| Typical purity grade | 95% or higher by HPLC | Research material; higher grades used as reference standards |
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.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. It was developed as a fragment analog of adrenocorticotropic hormone, modeled specifically on the ACTH(4-10) region. The first four residues reproduce that fragment, while a Pro-Gly-Pro tripeptide is appended at the C-terminus. Work on the compound originated in Russia, where it entered clinical use as an intranasal preparation. Its sequence places it among short regulatory peptides studied for effects on the central nervous system rather than on the adrenal axis.
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.
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.
==== Learning ==== Since the seminal studies of Charles Darwin on earthworm intelligence much work has been done on the capacity of earthworms, in particular members of the widespread Lumbricus terrestris, to learn, although some doubts were raised about the use of T-maze experiments for demonstrating learning by earthworms.
== Cell Turgor == Pressurized flow of latex has been studied in multiple Asclepias species as a form of defense in addition to the secondary metabolites stored in the latex. In order to augment the defense of the plant some non-articulated laticifer cells contain highly pressurized stores of latex. It has been noted that pressure may be produced by the osmotic uptake of water into the laticifer cell resulting in a turgid cell. When pierced the cell bursts and latex travels quickly through the canal system to stop the herbivore. A desert species, Bursera schlechtendalii, pressurizes the canals right where leaves attach to the stem so that when a grazer eats a leaf latex shoots out. This process is termed the “squirt gun” defense.
The protagonist of the story, Paul Espeseth, renames himself "Pending Vegan" in order to acknowledge his "increasing uneasiness with the relationship between man and beast." In 2016, a three-part Korean novel by Han Kang titled The Vegetarian was published in the U.S., which focuses on a woman named Young-hye, who "sees vegetarianism as a way of not inflicting harm on anything," with eating meat symbolizing human violence itself, and later identifies as a plant rather than as a human "and stops eating entirely." Some argued the book was more about mental illness than vegetarianism. Others compared it to fictional works by Margaret Atwood.
=== Example case === The Appalachian CAD event of October 2002 illustrates some shortcomings of short-term weather models for predicting a CAD event. This event was characterized by a stable saturated layer of cold air from surface up to the 700mb pressure level over the states of Virginia, North Carolina, and South Carolina. This mass of cold air was blocked by the Appalachians and did not dissipate even as a coastal cyclone to east strengthened. During this event, short term weather models predicted this cold mass clearing, leading to fairer weather conditions for the region such as warmer conditions and the absence of a layer of stratus clouds. However, the model performed poorly because they did not account for excessive solar radiation transmission through the cloud layers and shallow mixing promoted by the model's convective parameterization scheme. While these errors have been corrected in updated models, they resulted in an inaccurate forecast.
Once the heterologous protein has been fused with the bacterial cell surface protein, it is exposed to either an enzyme, a cell (expressing a target protein) or an antibody (usually fluorescently tagged), depending on the application of the experiment. The sample is then passed through a beam of light during FACS, in a very narrow stream of fluid so that only one cell can pass at a time, and the fluorescence emitted is detected. Information on the size of the cell can be obtained by the scattering of light and if binding of the heterologous protein with the target protein/cell has occurred, there will be more fluorescence emitted.
Sources: en.wikipedia.org
==== Cyanohydrins and cyanogenic glycosides ==== Cyanohydrins and their glycosides, referred to as cyanogenic glycosides, are widespread in nature and occur in several thousand plant species. More than one hundred naturally occurring cyanogenic glycosides have been identified. Plants utilize cyanogenic glycosides for defense and possibly also as a nitrogen storage buffer. They are biosynthesized from a limited number of amino acids and various carbohydrates. Upon tissue damage, the glycosides come into contact with enzymes (Β-glucosidase and hydroxynitrillyase), which first release the aglycone (a cyanohydrin) and subsequently cleave it into a carbonyl compound and toxic hydrocyanic acid. Amygdalin is a glycoside of mandelonitrile and one of the most widespread cyanogenic glycosides; it occurs particularly in the seeds of the rose family (Rosaceae), including cultivated apple, apricot, peach, plum, cherry, and almond tree. Whereas amygdalin is confined to the seeds of peaches, other parts of the plant predominantly contain prunasin. Prunasin is likewise a glycoside of mandelonitrile; however, its sugar moiety is a monosaccharide (rather than a disaccharide as in amygdalin). In almonds and bitter almonds, prunasin serves as a biosynthetic precursor of amygdalin. Prunasin is also present in laurel cherry. Prunasin and sambunigrin, along with several other cyanogenic glycosides, occur in passion flower; in papaya, prunasin predominates.
=== Lotion === Lotions are similar to solution but are thicker and tend to be more emollient in nature than the solution. They are usually oil mixed with water, and more often than not have less alcohol than solution. Lotions can be drying if they contain a high amount of alcohol.
=== Megaloblastic anemia === Neutrophil hypersegmentation is one of the earliest, most sensitive and specific signs of megaloblastic anemia (mainly caused by hypovitaminosis of vitamin B12 & folic acid). Nuclear hypersegmentation of DNA in neutrophils strongly suggests megaloblastosis when associated with macro-ovalocytosis. If megaloblastosis is suspected, a formal lobe count/neutrophil (i.e. lobe index) above 3.5% can be obtained. Hypersegmentation persists for an average of 14 days after institution of specific therapy.
Very strong: H1 Strong: 5-HT2A, α1-adrenergic Moderate: D2, mACh Weak: 5-HT2C, D1, α2-adrenergic In spite of its atypical nature and different profile of activity, trimipramine has been shown in head-to-head clinical studies to possess equivalent effectiveness to other antidepressants, including but not limited to other TCAs (e.g., amitriptyline, imipramine, doxepin, amineptine), tetracyclic antidepressants (TeCAs) (e.g., maprotiline), monoamine oxidase inhibitors (MAOIs) (e.g., phenelzine, isocarboxazid), and selective serotonin reuptake inhibitors (e.g., fluoxetine). In addition, trimipramine has been found to possess greater anxiolytic effects than other TCAs such as amitriptyline and doxepin in head-to-head comparisons. Indeed, its prominent anxiolytic effects have been said to distinguish it from most other TCAs. The atypicality of trimipramine in relation to its lack of monoamine reuptake inhibition is described as challenging the monoamine hypothesis of depression. The major metabolite of trimipramine, desmethyltrimipramine, is considered to possess pharmacological activity similar to that of other demethylated tertiary amine TCA variants.
Sources: en.wikipedia.org
Registered medical products are most often 0.1% nasal drops. Research suppliers ship lyophilized powder, usually in milligram quantities, which is dissolved before use. The active peptide is the same in both cases; presentation and excipients differ.
No. The peptide is synthetic, although it is modelled on a fragment of a naturally occurring hormone. ACTH(4-10) is generated when ACTH is cleaved, but the Pro-Gly-Pro extension is not a known endogenous sequence. It is therefore a designed analogue rather than a natural metabolite.
The label reflects reported effects on attention, memory and recovery after neurological injury in regional clinical reports. Those reports are mostly small and have not been widely replicated outside the region. The classification is descriptive and does not imply a single defined mechanism.
It is described as a synthetic analogue of the ACTH(4–10) fragment, a short segment of adrenocorticotropic hormone. Its sequence differs from that fragment and includes two proline residues, which influence stability and behaviour in solution.