This is a working overview of ACTH fragment, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
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.
Practical handling follows from those properties. Bulk material is best divided into single-use portions soon after receipt, because each thaw exposes the whole container to moisture and temperature cycling. Vials should be allowed to reach room temperature before opening to prevent condensation on the powder. Low-binding plasticware reduces loss of dilute solutions, and sterile filtration is used when a preparation must remain free of microbial growth. Records of batch number, reconstitution date and storage history are what allow a later analytical result to be interpreted meaningfully.
Identity and purity of Semax are established mainly by reversed-phase high-performance liquid chromatography coupled with mass spectrometry. The chromatographic trace gives a purity estimate as a percentage of total peak area, while electrospray or matrix-assisted laser desorption ionization confirms the molecular mass against the calculated value. Amino acid analysis and sequence-specific fragmentation provide further confirmation when a supplier's chain of custody is unclear. Vendors frequently quote a purity figure without stating the detection wavelength or the integration method, which limits how far one number can be compared with another.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide (ACTH fragment analog) | Not a steroid; does not belong to the melanocortin agonist drugs by marketing category |
| Molecular formula | C37H51N9O10S (commonly cited) | Reported values vary slightly with salt and counter-ion content |
| Appearance | White to off-white lyophilized powder | A single batch may appear as a loose cake or fluffy solid |
| Solubility | Freely soluble in water and aqueous buffer | Stock solutions are usually prepared in sterile water or saline |
| Typical storage | −20 °C or below, desiccated and protected from light | Seal opened vials promptly to limit moisture uptake |
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.
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.
Lyophilized material is chemically stable for extended periods when kept dry, cold, and protected from light. The powder is hygroscopic, so vials should be warmed to room temperature before opening to reduce condensation on the contents. Once dissolved, the peptide is far less stable because peptide bonds are susceptible to hydrolysis and the methionine residue can oxidize. Solutions are typically aliquoted and held at 2-8 °C for short intervals or frozen for longer ones, and repeated freeze-thaw cycles should be avoided.
Routine characterization relies on reversed-phase high-performance liquid chromatography to establish purity and on mass spectrometry to confirm molecular identity. Electrospray ionization and matrix-assisted laser desorption ionization are both used for mass verification. Amino acid analysis and peptide mapping can detect sequence errors. Common impurities include truncated sequences, methionine sulfoxide formed by oxidation, and deamidated products. Chromatograms are usually recorded near 214 nm, where the peptide backbone absorbs, and purity is reported as the percentage area of the principal peak.
Intramuscular fat (also known as intramuscular triglycerides, intramuscular triacylglycerol, or intramyocellular triacylglycerol [IMTG]) is located inside skeletal muscle fibers. It is stored in lipid droplets that exist in close proximity to the mitochondria, where it serves as an energy store that can be used during exercise. In humans, excess accumulation of intramuscular fat has been associated with conditions such as insulin resistance and type 2 diabetes. The human immunodeficiency virus (HIV)-lipodystrophy syndrome is associated with over-accumulation of intramuscular fat, which may contribute to AIDS wasting syndrome.
== Further reading == Alexander, Mark, and John Sparry. Jump Commander: In Combat with the 82nd Airborne in World War II. Philadelphia: Casemate, 2010. ISBN 1-935149-28-8 OCLC 506253036 Angress, Werner T. Witness to the Storm: A Jewish Journey from Nazi Berlin to the 82nd Airborne, 1920–1945. Durham, NC: Miriam Angress, 2012. ISBN 1-4774-5701-1 OCLC 804824030 Anzuoni, Robert P. I'm the 82nd Airborne Division!: A History of the All American Division in World War II After Action Reports. Atglen, PA : Schiffer Publishing, 2005. ISBN 0-7643-2347-4 OCLC 62555533 Anzuoni, Robert P. The All American: An Illustrated History of the 82nd Airborne Division, 1917 to the Present. Atglen, PA: Schiffer Pub, 2001. ISBN 0-7643-1321-5 OCLC 49935879 Barry, Robert F. Power Pack: The Dominican Republic, 1965–1966. Portsmouth, Va: Messenger, 1965. OCLC 6655474 Baugh, James Emory. From Skies of Blue: My Experiences with the Eighty-Second Airborne During World War II. New York: iUniverse, 2003. ISBN 0-595-74982-8 OCLC 64584040 Breuer, William B. Drop Zone, Sicily: Allied Airborne Strike, July 1943. Novato, CA: Presidio, 1983. ISBN 0-89141-196-8 OCLC 9945654 Burriss, T. Moffatt. Strike and Hold: A Memoir of the 82nd Airborne in World War II. Washington, D.C.: Brassey's, 2000. ISBN 1-57488-258-9 OCLC 43903491 Caraccilo, Dominic J. The Ready Brigade of the 82nd Airborne in Desert Storm: A Combat Memoir by the Headquarters Company Commander. Jefferson, N.C.: McFarland, 1993. ISBN 0-89950-829-4 OCLC 27265069 Carter, Ross S. Those Devils in Baggy Pants. Cutchogue, NY: Buccaneer Books, 1996.
==== Male–male competition ==== Most cephalopods engage in aggressive sex: a protein in the male capsule sheath stimulates this behavior. They also engage in male–male aggression, where larger males tend to win the interactions. When a female is near, the males charge one another continuously and flail their arms. If neither male backs away, the arms extend to the back, exposing the mouth, followed by the biting of arm tips. During mate competition males also participate in a technique called flushing. This technique is used by the second male attempting to mate with a female. Flushing removes spermatophores in the buccal cavity that was placed there by the first mate by forcing water into the cavity. Another behavior that males engage in is sneaker mating or mimicry – smaller males adjust their behavior to that of a female in order to reduce aggression. By using this technique, they are able to fertilize the eggs while the larger male is distracted by a different male. During this process, the sneaker males quickly insert drop-like sperm into the seminal receptacle.
== In research == In her book, Becoming a Stepfamily, Patricia Papernow (1993) suggests that each stepfamily goes through seven distinct stages of development, which can be divided into the early, middle, and late stages. The early stages consist of the fantasy, immersion, and awareness stages. In the fantasy stage, both children and parents are typically "stuck" in their fantasies or wishes for what their family could be like. The developmental task for this stage is for each member to articulate their wants and needs. In the Immersion stage, the family is typically struggling to live out the fantasy of a "perfect" blended family. In this stage, it is critical for the "insider spouse" (i.e. the biological parent who typically forms the emotional hub of the family) to understand that the feelings of the "outsider spouse" and children are real. The task of this stage is to persist in the struggle to become aware of the various experiences. This stage is followed by the awareness stage, in which the family gathers information about what the new family looks like (e.g., roles, traditions, "family culture") and how each member feels about it. The tasks of this stage are twofold: individual and joint. The individual task is for each member to begin to put words to the feelings they are experiencing, and to voice their needs to other family members. The joint task is for family members to begin to transcend the "experiential gaps" and to try to form an understanding of other members' roles and experiences. The middle stages consist of the mobilization and action stages.
=== The Americas === Europeans introduced saffron to the Americas when immigrant members of the Schwenkfelder Church left Europe with a trunk containing its corms. Church members had grown it widely in Europe. By 1730, the Pennsylvania Dutch cultivated saffron throughout eastern Pennsylvania. Spanish colonies in the Caribbean bought large amounts of this new American saffron, and high demand ensured that saffron's list price on the Philadelphia commodities exchange was equal to gold. Trade with the Caribbean later collapsed in the aftermath of the War of 1812, when many saffron-bearing merchant vessels were destroyed. Yet the Pennsylvania Dutch continued to grow lesser amounts of saffron for local trade and use in their cakes, noodles, and chicken or trout dishes. American saffron cultivation survives into modern times, mainly in Lancaster County, Pennsylvania.
Sources: en.wikipedia.org
=== 2000-present === In 2000, the company opened a central laboratory in Singapore, building on clinical-development services formed in Singapore in 1996. In 2013, it expanded the capacity of the laboratory by 50%. In March 2001, the company sold Covance Pharmaceutical Packaging Services to Fisher Scientific for $137.5 million. In August 2005, it acquired GFI Clinical Services, an 80-bed clinical pharmacology business, from West Pharmaceutical Services for $5.7 million. In April 2006, the company acquired eight early phase clinical pharmacology sites from Radiant Research for $65 million. In June 2006, it acquired Signet Laboratories, a provider of monoclonal antibodies used in the research of cancer, infectious disease, and neurodegenerative disease, for $8.95 million. In 2007, the company opened a laboratory in Shanghai, China. In 2019, it opened a research and development center in Shanghai. In August 2008, the company acquired a campus in Greenfield, Indiana from Eli Lilly and Company and executed a 10-year service drug development service agreement with Lilly. In December 2008, the company acquired a minority equity stake in Caprion Proteomics, a provider of proteomics-based services to the pharmaceutical industry. The company was acquired by Chicago Growth Partners in July 2012. In 2009, the company acquired the Gene Expression Laboratory from Merck & Co. and entered into a five-year, $145 million contract to provide Merck with genomic analysis services.
The first isolation of deoxyribonucleic acid (DNA) was done in 1869 by Friedrich Miescher. DNA extraction is the process of isolating DNA from the cells of an organism isolated from a sample, typically a biological sample such as blood, saliva, or tissue. It involves breaking open the cells, removing proteins and other contaminants, and purifying the DNA so that it is free of other cellular components. The purified DNA can then be used for downstream applications such as PCR, sequencing, or cloning. Currently, it is a routine procedure in molecular biology or forensic analyses. This process can be done in several ways, depending on the type of the sample and the downstream application, the most common methods are: mechanical, chemical and enzymatic lysis, precipitation, purification, and concentration. The specific method used to extract the DNA, such as phenol-chloroform extraction, alcohol precipitation, or silica-based purification. For the chemical method, many different kits are used for extraction, and selecting the correct one will save time on kit optimization and extraction procedures. PCR sensitivity detection is considered to show the variation between the commercial kits. There are many different methods for extracting DNA, but some common steps include:
reactivity The tendency of a particular chemical substance to undergo a chemical reaction, either by itself or with other substances, generally referring to either or both of two distinct observations: whether or not a substance reacts under a specific set of circumstances, and how quickly it reacts (i.e. the reaction rate). Thermodynamically, a chemical reaction occurs because the products (taken as a group) exist at a lower free energy than the reactants, and hence are more energetically "stable", but the concept of reactivity may also embody kinetic factors, depending on the usage. Chemical stability and chemical compatibility are related but distinct concepts.
The common form of the inhibitory term also obscures the relationship between the inhibitor binding to the enzyme and its relationship to any other binding term, be it the Michaelis–Menten equation or a dose response curve associated with ligand receptor binding. To demonstrate the relationship the following rearrangement can be made:
Sources: en.wikipedia.org
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.
It was developed in the Soviet Union during the early 1980s by groups at the Institute of Molecular Genetics in Moscow. Russian approval for intranasal use followed, and it has been marketed there since. Western laboratories encountered it mainly through translated literature and, later, through online research-chemical trade.
It holds a Russian registration as a prescription nasal product but has no approval from the European Medicines Agency or the United States Food and Drug Administration. Buyers outside Russia usually receive material sold strictly for laboratory research. That distinction matters because research-grade and pharmaceutical-grade products carry different documentation and testing expectations.
Suppliers normally quote a percentage of total chromatographic peak area, most often from reversed-phase HPLC. That figure says nothing about what the remaining percentage contains, and it depends on the detection wavelength used. A mass spectrometry result is a separate and stronger check on identity.