Heptapeptide comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2025-09-29. Where a claim depends on a specific study, the study is described rather than over-claimed.
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 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.
| 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.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It was derived from the ACTH(4-10) fragment, a short segment of adrenocorticotropic hormone that lacks the hormonal activity associated with the full-length peptide. Researchers at the Institute of Molecular Genetics in Moscow developed the compound during the 1980s. It has been registered as a pharmaceutical product in Russia and several neighbouring countries, where it is supplied as a nasal solution, and it is also sold internationally as a research chemical.
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.
Pain and stiffness (moderate to severe) in the neck, shoulders, upper arms, thighs, and hips, which inhibits activity, especially in the morning, but which usually persists to some degree throughout the day. Pain can also occur in the groin area and in the buttocks. The pain can be limited to one of these areas as well. It is a disease of the "girdles" meaning shoulder girdle or pelvic girdle. Fatigue and lack of appetite (possibly leading to weight loss) Anemia An overall feeling of illness or flu-like symptoms. Low-grade (mild) fever or abnormal temperature is sometimes present. High or spiking fevers may occur in patients who also have giant cell arteritis. Generalized weakness Note that this is generalized weakness, not muscle weakness. The presence of muscle weakness likely indicates a different diagnosis. Inflammatory swelling and pain of wrists and/or knees (only ~25% of cases) Pitting edema (non-inflammatory swelling) of wrists, ankles, hands, and feet (only ~10% of cases)
Euromac, an EU-funded consortium of medical and research institutes across Europe which is building a patient registry and raising standards of care for people with McArdle Disease. Archived 2021-04-22 at the Wayback Machine International Association for Muscle Glycogen Storage Disease (IamGSD). Walking With McArdle's - IamGSD videos EUROMAC Introduction - Video about McArdle disease and the EUROMAC Registry of McArdle disease and other rare glycogenoses patients
=== CO2 absorption === Hydrated products of Portland cement, such as concrete and mortars, slowly reabsorb atmospheric CO2 gas, which has been released during calcination in a kiln. This natural process, reversed to calcination, is called carbonation. As it depends on CO2 diffusion into the bulk of concrete, its rate depends on many parameters, such as environmental conditions and surface area exposed to the atmosphere. Carbonation is particularly significant at the latter stages of the concrete life - after demolition and crushing of the debris. It is estimated that nearly 30% of atmospheric CO2 generated by cement production is reabsorbed during the life-cycle of cement products. Carbonation process is considered as a mechanism of concrete degradation. It reduces pH of concrete that promotes reinforcement steel corrosion. However, as the product of Ca(OH)2 carbonation, CaCO3, occupies a greater volume, porosity of concrete reduces. This increases strength and hardness of concrete. There are proposals to reduce carbon footprint of hydraulic cement by adopting non-hydraulic cement, lime mortar, for certain applications. It reabsorbs some of the CO2 during hardening, and has a lower energy requirement in production than Portland cement. A few other attempts to increase absorption of carbon dioxide include cements based on magnesium (Sorel cement).
== Clinical significance == MetO increases with age in body tissues, which is believed by some to contribute to biological ageing. Moreover, levels of methionine sulfoxide reductase A (MsrA) decline in aging tissues in mice and in association with age-related disease in humans. There is thus a rationale for thinking that by maintaining the structureincreased levels or activity of MsrA might retard the rate of aging. Indeed, transgenic Drosophila (fruit flies) that overexpress methionine sulfoxide reductase show extended lifespan. However, the effects of MsrA overexpression in mice were ambiguous. MsrA is found in both the cytosol and the energy-producing mitochondria, where most of the body's endogenous free radicals are produced. Transgenically increasing the levels of MsrA in either the cytosol or the mitochondria had no significant effect on lifespan assessed by most standard statistical tests, and may possibly have led to early deaths in the cytosol-specific mice, although the survival curves appeared to suggest a slight increase in maximum (90%) survivorship, as did analysis using Boschloo's test, a binomial test designed to test greater extreme variation. Deletion of this gene has been associated with insulin resistance in mice, while overexpression reduces insulin resistance in old mice.
BioMarin Pharmaceutical Inc. is an American biotechnology company headquartered in San Rafael, California. It has offices and facilities in the United States, South America, Asia, and Europe. BioMarin's core business and research are in enzyme replacement therapies (ERTs). BioMarin was the first company to provide therapeutics for mucopolysaccharidosis type I (MPS I), by manufacturing laronidase (Aldurazyme, commercialized by Genzyme Corporation). BioMarin was also the first company to provide therapeutics for phenylketonuria (PKU). Over the years, BioMarin has been criticised for drug pricing and for specific instances of denying access to drugs in clinical trials.
Sources: en.wikipedia.org
King Crimson toured to support both albums, including double bill shows with Tool. The tour was documented on the live album Heavy ConstruKction in 2000 and the Heaven & Earth (1997–2008) box set in 2019. Led Zeppelin bassist John Paul Jones and his band supported Crimson on some live shows. On 9 November 2001, King Crimson released a limited edition live EP called Level Five, featuring three new pieces: "Dangerous Curves", "Level Five" and "Virtuous Circle", plus versions of "The ConstruKction of Light" and ProjeKct's "The Deception of the Thrush", followed by an unlisted track called "ProjeKct 12th and X" after one minute of silence. A second EP followed in October 2002, Happy with What You Have to Be Happy With. This featured eleven tracks (including a live version of "Larks' Tongues in Aspic, Part IV"). Half of the tracks were processed vocal snippets by Belew, and the songs themselves varied between Soundscapes, gamelan, heavy metal and blues. The double duo line-up released King Crimson's thirteenth album, The Power to Believe, in March 2003. Fripp described it as "the culmination of three years of Crimsonising". The album incorporated, reworked and retitled versions of "Deception of the Thrush" ("The Power to Believe III"), tracks from their previous two EPs, and an extract from a Fripp Soundscape with added instrumentation and vocals, alongside "Level Five" (the final installment of the "Larks' Tongues in Aspic" suite). The Power to Believe reached No. 162 in the UK and No. 150 in the US.
The evidence suggests "consumers pay lower electricity net-of-tax prices in countries where there are still incumbents owned by national governments." With the sharp rise in fossil fuel prices that came from the 2022 Russian invasion of Ukraine and the fossil fuel cartel OPEC deciding to restrict supply, the EU Commission proposed a windfall fossil fuel tax. There are not yet common standards on energy enterprise governance, although a number of member states ensure that workers and energy bill payers have the right to vote for directors.
=== Ministerial changes === The first ministerial change occurred in July 2023. Daniela Carneiro, after requesting disaffiliation from União Brasil, was replaced by Celso Sabino (UNIÃO-PA) in the Ministry of Tourism. On 6 September 2023, the first ministerial reform of the government was carried out, with the aim of obtaining greater governability. Lula replaced Ana Moser with the deputy André Fufuca (PP-BA) in the Ministry of Sport and Márcio França (PSB-SP) with Silvio Costa Filho, of the Republicanos, in the Ministry of Ports and Airports. Márcio França assumed the newly created Ministry of Entrepreneurship and Small Businesses. On Wednesday, 31 January 2024, Lula officially dismissed Flávio Dino from the leadership of the Ministry of Justice, after having nominated him to the position of justice of the Supreme Federal Court (STF) in the seat left by Rosa Weber with her compulsory retirement. To replace him, Ricardo Lewandowski was appointed, a former member of the Supreme Court who had left the body in the previous year, also due to compulsory retirement. On 6 September 2024, the Minister of Human Rights, Silvio Almeida, was dismissed from the position after it was disclosed that the NGO MeToo Brasil had received complaints of sexual harassment against him. On 9 September, the president announced that the Minas Gerais State deputy Macaé Evaristo (PT) will occupy the leadership of the Ministry of Human Rights.
The nociceptin opioid peptide receptor (NOP), also known as the nociceptin/orphanin FQ (N/OFQ) receptor or kappa-type 3 opioid receptor, is a protein that in humans is encoded by the OPRL1 (opioid receptor-like 1) gene. The nociceptin receptor is a member of the opioid subfamily of G protein-coupled receptors whose natural ligand is the 17 amino acid neuropeptide known as nociceptin (N/OFQ). This receptor is involved in the regulation of numerous brain activities, particularly instinctive and emotional behaviors. Antagonists targeting NOP are under investigation for their role as treatments for depression and Parkinson's disease, whereas NOP agonists have been shown to act as powerful, non-addictive painkillers in non-human primates. Although NOP shares high sequence identity (~60%) with the ‘classical’ opioid receptors μ-OP (MOP), κ-OP (KOP), and δ-OP (DOP), it possesses little or no affinity for opioid peptides or morphine-like compounds. Likewise, classical opioid receptors possess little affinity towards NOP's endogenous ligand nociceptin, which is structurally related to dynorphin A.
Sources: en.wikipedia.org
Nucleases are enzymes that cut DNA strands by catalyzing the hydrolysis of the phosphodiester bonds. Nucleases that hydrolyse nucleotides from the ends of DNA strands are called exonucleases, while endonucleases cut within strands. The most frequently used nucleases in molecular biology are the restriction endonucleases, which cut DNA at specific sequences. For instance, the EcoRV enzyme shown to the left recognizes the 6-base sequence 5′-GATATC-3′ and makes a cut at the horizontal line. In nature, these enzymes protect bacteria against phage infection by digesting the phage DNA when it enters the bacterial cell, acting as part of the restriction modification system. In technology, these sequence-specific nucleases are used in molecular cloning and DNA fingerprinting. Enzymes called DNA ligases can rejoin cut or broken DNA strands. Ligases are particularly important in lagging strand DNA replication, as they join the short segments of DNA produced at the replication fork into a complete copy of the DNA template. They are also used in DNA repair and genetic recombination.
Cyberwarfare in the United States is a part of the American military strategy of proactive cyber defence and the use of cyberwarfare as a platform for attack. The new United States military strategy makes explicit that a cyberattack is casus belli just as a traditional act of war. U.S. government security expert Richard A. Clarke, in his book Cyber War (May 2010), had defined "cyberwarfare" as "actions by a nation-state to penetrate another nation's computers or networks for the purposes of causing damage or disruption." The Economist describes cyberspace as "the fifth domain of warfare," and William J. Lynn, U.S. Deputy Secretary of Defense, states that "as a doctrinal matter, the Pentagon has formally recognized cyberspace as a new domain in warfare . . . [which] has become just as critical to military operations as land, sea, air, and space." When Russia was still a part of the Soviet Union in 1982, a portion of a Trans-Siberia pipeline within its territory exploded, allegedly due to a Trojan Horse computer malware implanted in the pirated Canadian software by the Central Intelligence Agency. The malware caused the SCADA system running the pipeline to malfunction. The "Farewell Dossier" provided information on this attack, and wrote that compromised computer chips would become a part of Soviet military equipment, flawed turbines would be placed in the gas pipeline, and defective plans would disrupt the output of chemical plants and a tractor factory.
Among numerous advances in experimental techniques he has developed experimental methods for using DNA microarrays to investigate the basic principles of genome organization. Member Natl. Acad. Sci. USA. Thomas Bruice (1925–2019). American bioorganic chemist at UC Santa Barbara, pioneering researcher in chemical biology. Member Natl. Acad. Sci. USA.
=== Flight-time equivalent dose === Natural background radiation typically increases with altitude above the earth's surface. Utilizing this phenomenon, dose resulting from radiological exposures can be expressed in units of flight-time. Flight-time equivalent dose is defined as the time spent in an aircraft at cruising altitude required to receive a radiological dose approximately equivalent to a radiological exposure such as a medical x-ray. One hour of flight-time is approximately equivalent to a dose of 0.004 millisieverts.
There are also common comorbid psychiatric conditions with aging anorexics, including major depression, anxiety disorder, obsessive compulsive disorder, bipolar disorder, schizophrenia, and dementia. The signs and symptoms that go along with anorexia of aging are similar to what is observed in adolescent anorexia, including sudden weight loss, unexplained hair loss or dental problems, and a desire to eat alone. There are also several medical conditions that can result from anorexia in the elderly. An increased risk of illness and death can be a result of anorexia. There is also a decline in muscle and bone mass as a result of a reduction in protein intake during anorexia. Another result of anorexia in the aging population is irreparable damage to kidneys, heart or colon and an imbalance of electrolytes. Many assessments are available to diagnose anorexia in the aging community. These assessments include the Simplified Nutritional Assessment Questionnaire (SNAQ) and Functional Assessment of Anorexia/Cachexia Therapy (FAACT). Specific to the geriatric populace, the interRAI system identifies detrimental conditions in assisted living facilities and nursing homes. Even a simple screening for nutritional insufficiencies such as low levels of important vitamins, can help to identify someone who has anorexia of aging. Anorexia in the elderly should be identified by the retirement communities but is often overlooked, especially in patients with dementia.
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.
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.