If you have been reading about ACTH(4-10) 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 2026-03-14. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
Regulatory status differs sharply between jurisdictions. In Russia the peptide is registered as a prescription nasal preparation, while agencies such as the United States Food and Drug Administration have not approved it for any indication. Products sold elsewhere are typically labeled for laboratory research only, and such labels shift responsibility for safe handling to the purchaser. Because the same name covers pharmaceutical-grade nasal drops and bulk research powder, identity and purity documentation becomes the main practical concern when comparing sources.
Semax is a synthetic seven-amino-acid peptide whose sequence extends the ACTH(4-10) fragment with a C-terminal proline-glycine-proline tripeptide. The commonly cited sequence is Met-Glu-His-Phe-Pro-Gly-Pro, giving a molecular formula near C37H51N9O10S and a molecular weight close to 813.9 g/mol. It belongs to the broader class of synthetic ACTH fragments studied for central nervous system effects rather than for adrenal steroid stimulation. In practice the material appears as a lyophilized white powder for laboratory work or as a dilute saline solution in clinical settings.
Development is attributed to researchers at the Institute of Molecular Genetics in Moscow during the early 1980s, building on earlier Soviet work with ACTH fragments. Russian regulatory approval followed for intranasal use, and the compound has remained commercially available there for decades. Most published human data originate from Russian and, later, some Eastern European clinical reports, which are not always accessible in English translation. Outside that region the material is generally handled as a research chemical rather than a licensed medicine.
| Property | Value | Notes |
|---|---|---|
| Molecular weight | ~813.9 Da (free heptapeptide) | N-acetylated form is about 42 Da heavier |
| Residue count | 7 (heptapeptide) | Four residues from ACTH(4-10), three added |
| Appearance | White to off-white powder | Usually supplied lyophilized |
| Solubility class | Freely soluble in water | Also dissolves in DMSO and polar organic solvents |
| Related parent fragment | ACTH(4-10) | Parent motif is Met-Glu-His-Phe |
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.
Scientific literature on semax is unevenly distributed. A substantial share of published work originates from a small number of laboratories in Russia, while independent replication elsewhere is limited. Human data consist mostly of small trials with short follow-up, and several reported outcomes rely on subjective rating scales. Questions about how much intact peptide reaches the central nervous system after nasal administration, and how long it persists there, are still unresolved. The compound is best described as an active research subject rather than a settled pharmacological agent.
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.
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=== Production during the Manhattan Project === During World War II the U.S. government established the Manhattan Project, for developing an atomic bomb. The three primary research and production sites of the project were the plutonium production facility at what is now the Hanford Site, the uranium enrichment facilities at Oak Ridge, Tennessee, and the weapons research and design lab, now known as Los Alamos National Laboratory, LANL.
Observations and theories regarding nature and human health, separate from Western traditions, had emerged independently in other civilizations such as those in China and the Indian subcontinent. In ancient China, earlier conceptions can be found dispersed across several different disciplines, including the work of herbologists, physicians, alchemists, and philosophers. The Taoist tradition of Chinese alchemy, for example, emphasized health (with the ultimate goal being the elixir of life). The system of classical Chinese medicine usually revolved around the theory of yin and yang, and the five phases. Taoist philosophers, such as Zhuangzi in the 4th century BCE, also expressed ideas related to evolution, such as denying the fixity of biological species and speculating that species had developed differing attributes in response to differing environments. One of the oldest organised systems of medicine is known from ancient India in the form of Ayurveda, which originated around 1500 BCE from Atharvaveda (one of the four most ancient books of Indian knowledge, wisdom and culture). The ancient Indian Ayurveda tradition independently developed the concept of three humours, resembling that of the four humours of ancient Greek medicine, though the Ayurvedic system included further complications, such as the body being composed of five elements and seven basic tissues. Ayurvedic writers also classified living things into four categories based on the method of birth (from the womb, eggs, heat & moisture, and seeds) and explained the conception of a fetus in detail.
Serum levels of the C21 11-oxygenated steroids: 21-deoxycorticosterone, also known as 11β-hydroxyprogesterone (11OHP4) and 21-deoxycortisol (21dF), have been known to be elevated in both non-classical and classical forms of CAH, and liquid chromatography–mass spectrometry profiles that include these steroids have been proposed for clinical applications, including newborn screening. Classical CAH patients receiving glucocorticoid therapy had C19 11-oxygenated steroid serum levels that were elevated compared to healthy controls. In CAH patients with poor disease control, 11-oxygenated androgens remain elevated for longer than 17OHP, thus serving as a better biomarker for the effectiveness of the disease control. In males with CAH, 11-oxygenated androgen levels may indicate the presence of testicular adrenal rest tumors.
From 1996 to 2002 additional functionality was included, from wireless networking and georeferencing of samples, to the adoption of XML standards and Internet purchasing. As of 2012, some LIMS have added additional characteristics such as clinical functionality, electronic laboratory notebook (ELN) functionality, as well a rise in the software as a service (SaaS) distribution model.
Sources: en.wikipedia.org
== Biosynthesis == In Bacillus cereus, cereulide is biosynthesised by the non-ribosomal peptide synthetase of the heterodimer proteins CesA and CesB. In non-ribosomal peptide synthetase, individual amino acids are added, modified, and linked. Addition is facilitated by the adenylation (A) domain. Modification is accomplished by the ketoreductase (KR) and epimerization (E) domains. Finally, the growing peptides are linked by condensation domains. The transportation between domains is facilitated by a peptide carrier protein or thiolation (T) domain, which houses the growing peptide chain. Additionally, a thioesterase (TE) domain is used by the final module to cleave and cyclize the final peptide product. The peptides produced from both CesA and CesB are linked with an ester rather than amide bond; given the cyclic structure of cereulide, this cyclic ester (or lactone) linkage makes cereulide a depsipeptide. CesA is a 387 kDa heterodimer protein composed of CesA1 and CesA2 modules. CesA1 adds ketoisocaproic acid to the adenylation domain. The thiolation domain will then move the ketoisocaproic acid along the ketoreductase domain, which reduces ketoisocaproic acid into D-α-hydroxyisocaproic acid with the cofactor NADPH. In module CesA2, L-alanine is added to the adenylation domain. The condensation domain will facilitate a nucleophilic attack by the free amine on L-alanine onto the thioester of D-α-hydroxyisocaproic acid (D-HIC) on the CesA1 module. This event links the peptides and situates the growing peptide molecule on the thiolation domain of CesA2.
From clinical trials, only 14% of heart attacks occur from artery closure at plaques producing 75% or greater stenosis before the vessel closing. If the fibrous cap separating a soft atheroma from the bloodstream within the artery ruptures, tissue fragments are exposed and released. These tissue fragments are very clot-promoting, containing collagen and tissue factor; they activate platelets and activate the system of coagulation. The result is the formation of a thrombus (blood clot) overlying the atheroma, which obstructs blood flow acutely. With the obstruction of blood flow, downstream tissues are starved of oxygen and nutrients. If this is the myocardium (heart muscle) angina (cardiac chest pain) or myocardial infarction (heart attack) develops.
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== January 11, 1982 (Monday) == The lowest temperature ever recorded in England was measured at Newport, Shropshire, where the thermometer reading was −26.1 °C (−15.0 °F). Filming began on Return of the Jedi, the third film in the Star Wars franchise, and the conclusion of the original trilogy, with production starting at sound stages the Elstree Studios in England at Borehamwood, Hertfordshire. Born: Denis Kolodin, Russian footballer with 23 caps for the Russia national team; in Kamyshin, Russian SFSR, Soviet Union Blake Heron, American actor known for his starring role in the 1996 film Shiloh; in Rockville Centre, New York (d. from a drug overdose, 2017) Died: Jiro Horikoshi, Japanese aeronautical engineer who designed the Zero fighter. A. W. Haydon, 75, American inventor wand specialist in miniaturization, known for his invention of 82 devices and innovations, including the microswitch used in computers, as well other devices for use by the general public, by the U.S. military and by NASA Sir Kenneth Strong, 81, British Army Major General and advisor of the Normandy Landings on D-Day in 1944, as well as negotiating the surrender of both Italy and Japan Carl M. Voyles, 83, American Canadian football head coach for the Hamilton Tiger-Cats, known for guiding the team to winning the 1953 Grey Cup Manya Surve, 37, Indian gangster, suspected in multiple murders and robberies, became the first of 622 criminals in Bombay to die in an "encounter killing" by police in the Maharashtra state.
Sources: en.wikipedia.org
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.
Semax is a synthetic analog of the ACTH(4-10) fragment rather than a copy of the full hormone. Truncation plus the added tail removes the steroidogenic portion of ACTH. That distinction explains why it is studied for nervous-system effects instead of adrenal stimulation.
It is registered as a prescription product in Russia and has been used there clinically, chiefly by the intranasal route. No approval exists in the United States or the European Union. Availability elsewhere typically falls under research-chemical distribution, with varying purity documentation.
It is a short synthetic peptide built from seven amino acids: methionine, glutamic acid, histidine, phenylalanine and three prolines. The sequence derives from the 4-10 fragment of adrenocorticotropic hormone with an added proline-glycine-proline tail. No plant or animal extract is involved; the material is produced by solid-phase peptide synthesis.