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Semax Background And Molecular Structure — Explained

By Editorial Desk · published 2025-09-09 · last reviewed 2025-09-26 · News

The short version of ACTH(4–10) fits in a sentence. The long version — which is the one that helps — is below.

Reviewed 2025-09-26. Anything still debated is marked as such rather than presented as settled.

Semax Background and Molecular Structure

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.

Semax Background and Chemistry

The compound is registered in Russia as a pharmaceutical product, most commonly formulated as a nasal solution, and has been used in that setting since the 1990s. Outside that jurisdiction it is generally handled as a research chemical rather than an approved medicine. Regulatory status therefore differs sharply between countries, and material sold internationally may not correspond to the Russian pharmaceutical formulation. Documentation with commercial samples is typically limited to a certificate of analysis covering purity and identity, not clinical status or local legal classification.

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.

Semax at a glance

PropertyValueNotes
Molecular weight~813.9 Da (free heptapeptide)N-acetylated form is about 42 Da heavier
Residue count7 (heptapeptide)Four residues from ACTH(4-10), three added
AppearanceWhite to off-white powderUsually supplied lyophilized
Solubility classFreely soluble in waterAlso dissolves in DMSO and polar organic solvents
Related parent fragmentACTH(4-10)Parent motif is Met-Glu-His-Phe

Semax Origin and Molecular Structure

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.

The compound was developed in the 1980s at the Institute of Molecular Genetics in Moscow, where it emerged from research on short ACTH fragments and their effects on the central nervous system. Russian pharmaceutical listings describe it as a nootropic and neuroprotective agent, most often formulated as nasal drops. It is not a marketed medicine in the United States or the European Union, and no pharmacopoeial monograph covers it. Consequently, most published clinical experience with the substance originates from a small number of research centres, mainly in Russia and neighbouring countries.

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Semax Peptide Background and Identity

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.

Semax Structure and Research Background

Clinical evidence consists largely of small trials with modest sample sizes, often without independent replication. Reported endpoints include cognitive scores, recovery after stroke, and visual function, but study designs vary widely and few trials meet contemporary reporting standards. Systematic reviewers have noted a high risk of bias in several of these reports. No large multicenter trial conducted outside Russia has been published. The compound is therefore best described as investigational in most jurisdictions, with its clinical role still unresolved.

Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its chain combines the first seven residues of corticotropin with a C-terminal proline-glycine-proline extension, a modification intended to slow enzymatic breakdown. The free peptide has a molecular mass near 813.9 daltons. It belongs to the class of ACTH-derived fragments studied for central nervous system activity rather than for adrenal steroid stimulation. This structural relationship to a natural hormone fragment is the usual starting point for describing the compound in the literature.

Further detail

After electrophoresis is complete, the molecules in the gel can be stained to make them visible. DNA may be visualized using ethidium bromide which, when intercalated into DNA, fluoresce under ultraviolet light, while protein may be visualised using silver stain or Coomassie brilliant blue dye. Other methods may also be used to visualize the separation of the mixture's components on the gel. If the molecules to be separated contain radioactivity, for example in a DNA sequencing gel, an autoradiogram can be recorded of the gel. Photographs can be taken of gels, often using a gel doc system. Gels are then commonly labelled for presentation using a number of tools, such as Adobe Illustrator, GIMP, ImageJ, Microsoft PowerPoint, and sciugo.

Polypropylene glycol or polypropylene oxide is the polymer (or macromolecule) of propylene glycol. Chemically it is a polyether, and, more generally speaking, it's a polyalkylene glycol (PAG) H S Code 3907.2000. The term polypropylene glycol or PPG is reserved for polymer of low- to medium-range molar mass when the nature of the end-group, which is usually a hydroxyl group, still matters. The term "oxide" is used for high-molar-mass polymer when end-groups no longer affect polymer properties. Between 60 and 70% of propylene oxide is converted to polyether polyols by the process called alkoxylation.

Nonetheless, ECB Vice President Luis de Guindos stated that central bank liquidity swap lines between the Federal Reserve and the ECB remained "business as usual". International Monetary Fund Director Kristalina Georgieva also spoke in defense of Powell and the Federal Reserve's independence given the role of the United States dollar as the world's reserve currency.

The third mechanism responsible for the translocation is based on the formation of the inverted micelles. Inverted micelles are aggregates of colloidal surfactants in which the polar groups are concentrated in the interior and the lipophilic groups extend outward into the solvent. According to this model, a penetratin dimer combines with the negatively charged phospholipids, thus generating the formation of an inverted micelle inside of the lipid bilayer. The structure of the inverted micelles permits the peptide to remain in a hydrophilic environment. Nonetheless, this mechanism is still a matter of discussion, because the distribution of the penetratin between the inner and outer membrane is non-symmetric. This non-symmetric distribution produces an electrical field that has been well established. Increasing the amount of peptide on the outer leaflets causes the electric field to reach a critical value that can generate an electroporation-like event. The last mechanism implied that internalization occurs by peptides that belong to the family of primary amphipathic peptides, MPG and Pep-1. Two similar models have been proposed based on physicochemical studies, consisting of circular dichroism, Fourier transform infrared, and nuclear magnetic resonance spectroscopy. These models are associated with electrophysiological measurements and investigations that have the ability to mimic model membranes such as monolayer at the air-water interface. The structure giving rise to the pores is the major difference between the proposed MPG and Pep-1 model.

40 mg/day: India National Institute of Nutrition, Hyderabad 45 mg/day or 300 mg/week: the World Health Organization 80 mg/day: the European Commission Council on nutrition labeling 90 mg/day (males) and 75 mg/day (females): Health Canada 2007 90 mg/day (males) and 75 mg/day (females): United States National Academy of Sciences 100 mg/day: Japan National Institute of Health and Nutrition 110 mg/day (males) and 95 mg/day (females): European Food Safety Authority

Sources: en.wikipedia.org

Background from the literature

=== Youth levels === Townsend represented England at under-16, under-17 and under-19 level. He played three times for the under-16s between 2006 and 2007, making his debut in a 1–1 draw away with Wales on 20 October 2006 and his last appearance in a 2–0 away loss to Germany in April 2007. He scored twice on his under-17 debut, in a 6–1 win over Northern Ireland in August 2007, and went on to make six appearances, the last in a 0–0 draw with Portugal on 5 February 2008. Townsend's first two appearances at under-19 level came in the group stage of the 2009 European Championship; he was an unused substitute in the final, which England lost to Ukraine. He played four times in 2010, once as a starter in a friendly, and three times as a substitute in qualifiers for the 2010 competition. Townsend received his first call up to the England under-21 team in October 2012 for the Euro 2013 play-off matches against Serbia. He made his debut in the first leg as a 65th-minute substitute for Liverpool's Raheem Sterling. He also played in two U21 friendlies, in 2012 and 2013. In May 2013, Townsend was charged by The Football Association over alleged breaches of its rules on betting. He subsequently voluntarily withdrew from England's squad for the upcoming European Under-21 Championship finals. He later admitted to charges under the FA's rules for breaching football betting regulations. After a personal hearing, he was fined £18,000 and suspended for four months backdated to 23 May, with three months suspended until 1 July 2016.

=== Abnormal collagen === Abnormal collagen fibrils are often found in diabetes. Due to increased levels of lysyl oxidase, collagen increases cross-linking. This thickens the basement membrane, another hallmark of NL.

Alpha collagen is specifically designed to deliver specific ratios of α- chain peptides as building blocks. The targeted cells can process the α- chain peptides to form triple helix collagen, and replenish the collagen in the targeted site. Scientists believe that Alpha collagen can help to deliver specific ratios of peptides to benefit the targeted cells. Alpha collagen is designed to be used as a supplement for osteoarthritis, based on the theory of the different environments of the extracellular matrix (ECM). The ECM of joint cartilage comprises many classes of macromolecules; collagen (type I, II, VI, X collagen fibrils) and proteoglycans. The ratio and the proportion of collagen play an important role in the tensile and compressive strength, as well as the elasticity of the tissue. The content of collagen in cartilage is different between joints and soft tissue structures. For example, cartilage in the knee has a different structure to the ankle. Cartilage, skin, and spinal discs are subject to continuous regeneration during which anabolic and catabolic processes are in equilibrium. Any imbalance in this equilibrium between matrix degeneration and regeneration results in a decrease in the components of the ECM, and leads to loss of chondral damage. Therefore, it is important to tackle the degenerative process before the inflammatory metalloproteases set in by replenishing the collagen in the ECM. Collagen supplementation has been shown in research studies (in vitro and in vivo) to increase the thickness or volume of the cartilage tissue.

Cancellous bone, spongy bone, or trabecular bone is the internal tissue of the skeletal bone and is an open-cell porous network that follows the material properties of biofoams. Cancellous bone has a higher surface-area-to-volume ratio than cortical bone and it is less dense. This makes it weaker and more flexible. The greater surface area also makes it suitable for metabolic activities such as the exchange of calcium ions. Cancellous bone is typically found at the ends of long bones, near joints, and in the interior of vertebrae. Cancellous bone is highly vascular and often contains red bone marrow where hematopoiesis, the production of blood cells, occurs. The primary anatomical and functional unit of cancellous bone is the trabecula. The trabeculae are aligned towards the mechanical load distribution that a bone experiences within long bones such as the femur. As far as short bones are concerned, trabecular alignment has been studied in the vertebral pedicle. Thin formations of osteoblasts covered in endosteum create an irregular network of spaces, known as trabeculae. Within these spaces are bone marrow and hematopoietic stem cells that give rise to platelets, red blood cells and white blood cells. Trabecular marrow is composed of a network of rod- and plate-like elements that make the overall organ lighter and allow room for blood vessels and marrow. Trabecular bone accounts for the remaining 20% of total bone mass but has nearly ten times the surface area of compact bone.

Sources: en.wikipedia.org

Further detail

== Interactions == Lixisenatide and other GLP-1 receptor agonist slow emptying of stomach contents, which may affect the absorption of orally administered medications. For effective use, oral contraceptives should be taken 1 hour before or 11 hours after taking lixisenatide-containing products. Acetaminophen and antibiotics are among other drugs that are affected by this action of lixisenatide.

== Composition == Silk is made up of two primary proteins; a fibrous protein known as fibroin, and a sticky protein known as sericin, with the two comprising 70–80% and 20–30% of silk, respectively. The source of these silk amino acids is typically the cocoons of the domestic silk moth, Bombyx mori, although other sources are known. Silk peptides are produced by acid hydrolysis of silk followed by neutralization of excess acid, filtration, and further processing steps to remove salts and other impurities followed by freeze drying. The resultant product contains a mixture of peptides typically between 2 and 20 amino acids in length, with a major component being the 18 amino acid fragment GAGAGSGAGAGSGAGAGS comprising three repeat units of the β‑sheet motif Gly-Ala-Gly-Ala-Gly-Ser derived from the repetitive crystalline domain of silk fibroin protein.

Potassium salts such as carnallite, langbeinite, polyhalite, and sylvite form extensive evaporite deposits in ancient lake bottoms and seabeds, making extraction of potassium salts in these environments commercially viable. The principal source of potassium – potash – is mined in Canada, Russia, Belarus, Kazakhstan, Germany, Israel, the U.S., Jordan, and other places around the world. The first mined deposits were located near Staßfurt, Germany, but the deposits span from Great Britain over Germany into Poland. They are located in the Zechstein and were deposited in the Middle to Late Permian. Canada leads the world production of potash; the easiest deposits to mine lie 1,000 meters (3,300 feet) below the surface of the Canadian province of Saskatchewan. The water of the Dead Sea is used by Israel and Jordan as a source of potash, while the concentration in normal oceans is too low for commercial production at current prices.

"Molecular mechanisms of insulin resistance and associated diseases". Clinica Chimica Acta. 375 (1–2): 20–35. doi:10.1016/j.cca.2006.07.005. PMID 16956601. Tomazic, J; Karner, P; Vidmar, L; Maticic, M; Sharma, PM; Janez, A (2005). "Effect of metformin and rosiglitazone on lipid metabolism in HIV infected patients receiving protease inhibitor containing HAART". Acta Dermatovenerologica Alpina, Pannonica et Adriatica. 14 (3): 99–105. PMID 16200335. Tomažič, Janez; Silič, Anja; Karner, Primož; Vidmar, Ludvik; Matičič, Mojca; Poljak, Mario; Ihan, Alojz; Janež, Andrej (2004). "Lipodystrophy and metabolic abnormalities in Slovenian HIV-infected patients". Wiener Klinische Wochenschrift. 116 (21–22): 755–9. doi:10.1007/s00508-004-0268-9. PMID 15628647. S2CID 24715784. Tomazic, M.; Janez, A.; Sketelj, A.; Kocijancic, A.; Eckel, J.; Sharma, P. (2002). "Comparison of alterations in insulin signalling pathway in adipocytes from type II diabetic pregnant women and women with gestational diabetes mellitus". Diabetologia. 45 (4): 502–8. doi:10.1007/s00125-002-0791-z. PMID 12032625. (Retracted) Hevener, A.; Reichart, D.; Janez, A.; Olefsky, J. (2002). "Female Rats Do Not Exhibit Free Fatty Acid-Induced Insulin Resistance". Diabetes. 51 (6): 1907–12. doi:10.2337/diabetes.51.6.1907. PMID 12031980. Hevener, A. L.; Reichart, D.; Janez, A.; Olefsky, J. (2001). "Thiazolidinedione Treatment Prevents Free Fatty Acid-Induced Insulin Resistance in Male Wistar Rats". Diabetes. 50 (10): 2316–22. doi:10.2337/diabetes.50.10.2316. PMID 11574414. Ravnik-Oblak, M; Janez, A; Kocijanicic, A (2001).

=== Recombinant human CNTF (Axokine) === A recombinant version of human CNTF (rhCNTF), trade name Axokine, is a modified version with a 15 amino acid truncation of the C-terminus and two amino acid substitutions. It is three to five times more potent than CNTF in in vitro and in vivo assays and has improved stability properties. Like CNTF it is a neurotrophic factor, and may stimulate nerve cells to survive. It was tested in the 1990s as a treatment for amyotrophic lateral sclerosis. It did not improve muscle control as much as expected, but trial participants did report a loss of appetite. Phase III clinical trials for the drug against obesity were conducted in 2003 by Axokine's maker, Regeneron Pharmaceuticals, demonstrating a small positive effect in some patients, but the drug was not commercialized. A major problem with the treatment was that in nearly 70% of the subjects tested, antibodies against Axokine were produced after approximately three months of treatment. In the minority of subjects who did not develop the antibodies, weight loss averaged 12.5 pounds in one year, versus 4.5 pounds for placebo-treated subjects. In order to obtain this benefit, subjects needed to receive daily subcutaneous injections of one microgram Axokine per kilogram body weight. Xencor patent application raises the disturbing idea that subjects producing antibodies against CNTF analogues may eventually suffer severe adverse effects, as these antibodies could potentially interfere with the neuroprotective functions of endogenous CNTF.

Sources: en.wikipedia.org

Frequently asked questions

What is the amino acid sequence of Semax?

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.

How does Semax relate to ACTH?

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.

Is Semax an approved medicine?

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.

Is semax an approved medicine?

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.

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