The short version of N-acetyl Semax fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-07-26 and is reviewed periodically as new material appears.
Published research has focused mainly on neurological and cognitive endpoints in animal models, with proposed mechanisms involving brain-derived neurotrophic factor and related signalling pathways. A substantial share of the human data originates from a limited number of research groups, and independent replication in other countries remains sparse. Regulatory status reflects that distribution: the peptide is registered as a medicine in Russia and appears in some neighbouring markets, while elsewhere it is handled as a research chemical without approved therapeutic labelling. Questions about dose-response relationships, long-term effects, and comparability across studies are still open.
Lyophilised powder is normally kept at -20 °C in a desiccated container, with some suppliers recommending -80 °C for long-term archival storage. Repeated freeze-thaw cycles are the most common cause of avoidable loss, so aliquoting before freezing reduces variability between working sessions. Dissolved peptide is far less stable than the dry solid and is usually prepared fresh or held briefly at 4 °C. Aqueous solutions support both hydrolysis of the backbone and oxidation of the N-terminal methionine, and these two routes dominate degradation under ordinary laboratory conditions.
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.
| Property | Value | Notes |
|---|---|---|
| Purity assay | RP-HPLC, UV 214 nm | Typical research grade 95 percent or higher |
| Mass confirmation | ESI-MS or MALDI-TOF | Compared with theoretical value |
| Main degradation route | Methionine oxidation | Sulfoxide formation in solution |
| Powder storage | -20 °C, desiccated | Amber vial, minimal headspace |
| Working solution | Sterile water or saline | Prepare fresh; avoid repeated thawing |
Material sold for laboratory use varies widely in stated purity and documentation. A certificate of analysis should list the analytical method, the column and detector used, and the observed purity value. Independent verification by an outside laboratory is the practical way to confirm identity when documentation is absent or internally inconsistent. Regulatory status differs by country, and a product legal in one jurisdiction may be unapproved or controlled in another.
Identity and purity of semax are established with reversed-phase high-performance liquid chromatography coupled to ultraviolet detection, usually at 214 nanometres. Mass spectrometry, most often electrospray ionisation in positive mode, confirms the molecular mass and reveals truncated sequences. Amino acid analysis and peptide mapping after enzymatic digestion provide additional structural confirmation. Laboratories typically report purity as the percentage area of the main peak, a figure that does not capture isomeric or oxidised variants unless the method resolves them.
The peptide is prone to several degradation pathways. Oxidation of the methionine residue produces a sulfoxide that elutes close to the parent peak in many chromatographic systems. Hydrolysis of peptide bonds and deamidation of susceptible residues in related sequences also reduce purity over time. Lyophilised material kept dry at minus twenty degrees Celsius and shielded from light is the most stable form commonly described in laboratory practice.
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.
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.
Published studies are dominated by animal models of stroke, ischemia, and cognitive impairment, with a smaller number of human trials conducted in Russia. Many of the human reports are small, single-center, and published in Russian-language journals, which limits independent scrutiny. Outcome measures vary between studies and often rely on clinician-rated scales rather than objective biomarkers. Systematic reviews have noted the methodological weaknesses and called for larger, preregistered trials before firm conclusions can be drawn.
Claims about enhanced focus, memory, or mood in healthy people rest mostly on anecdotal reports and community discussion rather than on controlled data. It remains unclear whether any cognitive benefit observed in patients recovering from brain injury would extend to uninjured users. Dose-response relationships, long-term safety, and interactions with other drugs are not well characterized in the peer-reviewed literature. Questions about optimal route of administration and treatment duration likewise remain open.
Semax binds to melanocortin receptors and is thought to influence neuronal survival and plasticity rather than to act through the adrenal axis. Laboratory work has shown increased expression of brain-derived neurotrophic factor and nerve growth factor in treated tissue. Changes in c-Fos, a marker of neuronal activation, have also been reported. Because the peptide is rapidly degraded by peptidases, its effects are generally attributed to downstream signaling cascades rather than to sustained receptor occupancy.
Semax 是人工设计的七肽，序列为 Met-Glu-His-Phe-Pro-Gly-Pro，骨架取自促肾上腺皮质激素片段 ACTH(4-10)。它于二十世纪八十年代在苏联的分子遗传学研究机构内合成。设计目标是保留该片段与注意力和记忆相关的活性，同时剔除促皮质激素释放等内分泌作用。此后俄罗斯将其登记为药品并进入临床使用。
当时的短肽研究普遍关注能否穿越血脑屏障、在低剂量下产生中枢效应，Semax 属于这一路线。鼻内给药是其主要使用方式，俄语文献报道的适应症涵盖缺血性卒中、短暂性脑缺血发作、认知功能减退以及视神经病变。这些研究大多发表在当地期刊上，样本规模与终点设置同西方试验惯例存在差异，国际同行对其临床证据的强度看法不一。
High-velocity: Between 600 m/s (2,000 ft/s) and 1,000 m/s (3,500 ft/s) Usually caused by powerful assault or hunting rifles and usually cause Gustilo Type 3 wounds. The risk of infection is especially high due to the large area of injury and destroyed tissue. Bullets from handguns are sometimes less than 300 m/s (980 ft/s) but with modern pistol loads, they usually are slightly above 300 m/s (980 ft/s), while bullets from most modern rifles exceed 750 m/s (2,500 ft/s). One recently developed class of firearm projectiles is the hyper-velocity bullet, such cartridges are usually made for achieving such high speed, purpose-built in factories or made by amateurs. Examples of hyper velocity cartridges include the .220 Swift, .17 Remington and .17 Mach IV cartridges. The US military commonly uses 5.56mm bullets, which have a relatively low mass as compared with other bullets (2,6-4,0 grams); however, the speed of these bullets is relatively fast (approximately 850 m/s (2,800 ft/s), placing them in the high velocity category). As a result, they produce a larger amount of kinetic energy, which is transmitted to the tissues of the target. High energy transfer results in more tissue disruption, which plays a role in incapacitation, but other factors such as wound size and shot placement are also important.
== Concept == In 1975, Pizza Hut began testing concepts with Applegate's Landing. with restaurants that featured Colonial-style exteriors and eclectic interiors that included a truck with a salad bar in the bed. The chain offered much of the same pizza and pasta dishes, with some additions like hamburgers and bread pudding. Applegate's Landing went defunct in the mid-1980s except for one location in McPherson, Kansas, that closed in late 1995.
== Other uses == Contraction (economics), a general slowdown in economic activity; the opposite of economic expansion Contraction (physics), change in the volume of matter in response to a change in temperature Lanthanide contraction, the decrease in size of the ionic radius of lanthanide elements with their growing atomic number Contracted (film), a 2013 horror thriller film by Eric England and its sequel Contracted: Phase II (2015) which directed by Josh Forbes
These adenylyl cyclases are toxins secreted by pathogenic bacteria such as Bacillus anthracis, Bordetella pertussis, Pseudomonas aeruginosa, and Vibrio vulnificus during infections. These bacteria also secrete proteins that enable the AC-II to enter host cells, where the exogenous AC activity undermines normal cellular processes. The genes for Class II ACs are known as cyaA, one of which is anthrax toxin. Several crystal structures are known for AC-II enzymes.
More recently, accelerator mass spectrometry has become the method of choice; it counts all the 14C atoms in the sample and not just the few that happen to decay during the measurements; it can therefore be used with much smaller samples (as small as individual plant seeds), and gives results much more quickly. The development of radiocarbon dating has had a profound impact on archaeology. In addition to permitting more accurate dating within archaeological sites than previous methods, it allows comparison of dates of events across great distances. Histories of archaeology often refer to its impact as the "radiocarbon revolution". Radiocarbon dating has allowed key transitions in prehistory to be dated, such as the end of the last ice age, and the beginning of the Neolithic and Bronze Age in different regions.
Sources: en.wikipedia.org
Hsc70 (Hsp73/HSPA8) is a constitutively expressed chaperone protein. It typically makes up one to three percent of total cellular protein. Hsp70 (encoded by three very closely related paralogs: HSPA1A, HSPA1B, and HSPA1L) is a stress-induced protein. High levels can be produced by cells in response to hyperthermia, oxidative stress, and changes in pH. Binding immunoglobulin protein (BiP or Grp78) is a protein localized to the endoplasmic reticulum. It is involved in protein folding there, and can be upregulated in response to stress or starvation. mtHsp70 or Grp75 is the mitochondrial Hsp70. The following is a list of human Hsp70 genes and their corresponding proteins:
== Academia == In 2004, Peña taught as an adjunct professor at the Catholic University of Asunción, teaching financial theory. In 2005, he became a professor of economic policy at the same establishment. In addition, Peña has contributed to scholarship on monetary policy and finance. In 2017, he was invited by the Professor and current Ecuadorian ambassador to Chile Roberto Izurieta to participate as a visiting professor at the Graduate School of Political Management of the George Washington University in Washington D.C., where Peña shared his experience on public administration in Paraguay. He also was the thesis advisor of Geovanny Vicente, CNN columnist and professor at Columbia University.
The gingiva often possess a textured surface that is referred to as being stippled (engraved points). Stippling only presents on the attached gingiva bound to underlying alveolar bone, not the freely moveable alveolar mucosa or free gingiva. Stippling used to be thought to indicate health, but it has since been shown that smooth gingiva is not an indication of disease, unless it is smooth due to a loss of previously existing stippling. Stippling is a consequence of the microscopic elevations and depressions of the surface of the gingival tissue due to the connective tissue projections within the tissue. The degree of keratinization and the prominence of stippling appear to be related. To be more specific, stippling occurs at sites of fusion of the epithelial ridges (also known as rete pegs – depression of epithelium) and correspond to the fusion of the valleys created by the connective tissue papillae (elevation of connective tissue papilla). An example of stippling could be dots found on a basketball or an orange.
is a parameter which measures the steepness of the power-law rise of the ascending flank of the first peak of the radial distribution function, and is quantitatively related to the repulsive part of the interatomic potential. Finally,
Westbrook* (1968), writer, son of syndicated columnist Sheilah Graham Westbrook Phillip Lopate (1964), essayist and fiction writer Ron Padgett (1964), poet and translator, winner of the Shelley Memorial Award in 2009 and Robert Frost Medal in 2018 Steven Millhauser (1965), novelist and winner of the Pulitzer Prize for Fiction for Martin Dressler: The Tale of an American Dreamer Aaron Fogel (1967), poet Eric Van Lustbader (1967), espionage and thriller novelist, writer of Jason Bourne novels Thomas Hauser (1968), author of nonfiction and biographer David Shapiro (1968), poet, literary critic, professor at William Paterson University Hilton Obenzinger (1969), novelist, poet, history and criticism writer Paul Auster (1970), postmodern writer; author of The New York Trilogy, Moon Palace, and the Brooklyn Follies Bob Holman (1970), poet and activist identified with the oral tradition David Lehman (1970), poet, editor of The Best American Poetry series Joshua Rubenstein (1971), writer, winner of a National Jewish Book Award in 2002 Alex Abella (1972), Cuban-American writer Brad Gooch (1973), writer, professor of English at William Paterson University John Prados (1973), author and historian on World War II and the Cold War Todd McEwen (1975), writer, professor at the University of Kent Stephen O'Connor (1975), writer and professor at Sarah Lawrence College Damien Bona (1977), chronicler of the Academy Awards Mason Wiley (1977), co-author of The Official Preppy Handbook Kevin Baker (1980), novelist and freelance journalist Jeffrey Harrison (1980), poet who won the 1988 Amy Lowell Poetry Travelling Scholarship Lou Antonelli (1981), science fiction writer Douglas Sadownick (1981), writer and psychologist Michael Friedman (1982), novelist and author Michael Azerrad (1983), author, journalist, musician Thomas Dyja (1984), writer, historian, winner of the 1997 Casey Award David Rakoff (1986), comedic essayist Louise Wareham Leonard (1987), writer Al Weisel (1987), freelance writer Adrienne Brodeur (1988), author, program director at Aspen Institute Glen Hirshberg (1988), author, recipient of the 2007 Shirley Jackson Award Adam Mansbach (1988), author and former professor of literature at Rutgers University–Camden Darryl Pinckney (1988), novelist, playwright, and essayist Mako Yoshikawa (1988), novelist, professor at Emerson College Ben Coes (1989), author of political thriller and espionage novels Wade Graham (1989), author, historian, environmentalist G. Winston James (1989), poet, author, activist Robert Salkowitz (1989), author on technology innovation Carol Guess (1990), novelist and poet; professor at Western Washington University John Reed (1990), novelist; author of Snowball's Chance David S. Levinson (1991), short-story writer and novelist Robert Kolker (1991), writer, author of Hidden Valley Road Kelly Link (1991), Hugo Award-winning author; founder of Small Beer Press; editor of St. Martin's Press's Year's Best Fantasy and Horror Loren Goodman (1991), postmodern poet, professor at Underwood International College Andrew Carroll (1992), author, editor, activist, and historian Jordan Davis (1992), poet John Bemelmans Marciano (1992), children's book author and illustrator, grandson of Ludwig Bemelmans, author of Madeline Marie Mutsuki Mockett (1992), writer Melissa de la Cruz (1993), writer known for work in young adult fiction Jay Michaelson (1993), writer and LGBTQ activist Maxine Swann (1994), fiction writer Robert Westfield (1994), writer who won two Lambda Literary Awards Megan McCafferty (1995), chick lit writer, Jessica Darling series, which were plagiarized by Kaavya Viswanathan Tova Mirvis (1995), author Saleemah Abdul-Ghafur (1996), author and Islamic activist Fredrik Stanton (1996), author of Great Negotiations and former publisher for the Columbia Daily Spectator Aravind Adiga (1997), Man Booker Prize-winning novelist Jamel Brinkley (1997), author, winner of the 2018 Ernest J. Gaines Award for Literary Excellence John Coletti (1997), author Gotham Chopra (1997), author, son of health advocate Deepak Chopra Lauren Grodstein (1997), author, professor of Rutgers University–Camden Abdi Nazemian (1998), Iranian-American author, winner of the 2017 Lambda Literary Award for Debut Fiction Trevor Shane (1998), writer Daniel Alarcón (1999), novelist Katherine Howe (1999), novelist, author of The Physick Book of Deliverance Dane Rebecca Pawel (1999), author of mystery novels; winner of the 2004 Edgar Allan Poe Award for Best First Novel Alex Marzano-Lesnevich (2001), author, winner of a 2018 Lambda Literary Award and Chautauqua Prize Fiona Sze-Lorrain (2003), French writer, poet, translator, musician Ben Dolnick (2004), writer, son of biographer Edward Dolnick, member of the Ochs-Sulzberger family that owns The New York Times Danielle Valore Evans (2004), fiction writer Adam Gidwitz (2004), author of best selling children's books Alaya Dawn Johnson (2004), author and winner of the 2015 Andre Norton Award Tongo Eisen-Martin (2004), poet laureate of San Francisco Sidik Fofana (2005), public school teacher and writer, winner of a 2023 Whiting Award Victoria Loustalot (2006), writer of memoir and essays Crystal Hana Kim (2009), writer, If You Leave Me Morgan Parker (2010), poet and Cave Canem Fellow Rachel Heng (2011), Singaporean writer Ben Philippe (2011), author, screenwriter, recipient of the 2020 William C. Morris Award Rowan Hisayo Buchanan (2012), British-American writer, recipient of the Betty Trask Award and the Authors' Club Best First Novel Award Sylvia Khoury (2012), writer and playwright, recipient of a 2021 Whiting Award Yanyi (2013), poet
Sources: en.wikipedia.org
Reversed-phase HPLC gives the main purity figure, most often with UV detection near 214 nanometres. Mass spectrometry then confirms the molecular mass. Together the two methods distinguish a correct sequence from a closely related impurity.
The main chemical risks are methionine oxidation and backbone hydrolysis in solution. Moisture and repeated temperature cycling accelerate both processes. Dry powder held cold and desiccated is considerably more stable than any reconstituted preparation.
It holds a medicine registration in Russia, where it has been used clinically for decades. In most other countries it is treated as a research chemical. That split explains the uneven distribution of clinical literature.
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.