heptapeptide is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2026-07-18. Where a claim depends on a specific study, the study is described rather than over-claimed.
Development took place during the 1980s at institutes of the Russian Academy of Sciences, where peptide fragments of ACTH were screened for cognitive and neuroprotective effects. The compound received regulatory approval in Russia as a nasal preparation, marketed for conditions such as ischemic stroke, transient ischemic attacks, and optic nerve disorders. Registration in other countries has not followed. Most published clinical reports originate from a small number of Russian research groups, and independent replication outside that setting remains limited. The regulatory status therefore differs sharply between Russia and the rest of the world.
Laboratory work points toward modulation of neurotrophic signaling, particularly expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal tissue. Studies also describe effects on monoamine turnover, inflammatory mediators, and oxidative markers. These observations come mainly from animal models and cultured cells, so the causal chain in humans is not firmly established. Whether the reported molecular changes translate into measurable clinical benefit is an open question. Reviews generally present the mechanism as plausible rather than demonstrated.
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.
| Property | Value | Notes |
|---|---|---|
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Heptapeptide; ACTH(4-10) analog extended at C-terminus |
| Molecular mass | ~813.9 Da | Free peptide, unmodified |
| Appearance | White to off-white powder | Typical lyophilized solid |
| Solubility | Soluble in water and saline | Also soluble in common aqueous buffers |
| Storage (solid) | -20 °C, desiccated | Protect from moisture and repeated thawing |
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.
Solid semax is typically supplied as a lyophilised powder that is hygroscopic and sensitive to moisture, light, and repeated temperature cycling. Long-term storage of the dry peptide is generally recommended at approximately -20 degrees Celsius, while shorter working periods may use refrigeration at 2 to 8 degrees Celsius. Vials should remain tightly closed and desiccated when brought to room temperature, because condensation can damage the material before it is weighed. Dividing a batch into aliquots is preferable to thawing one container repeatedly.
Dissolution is normally performed in water, phosphate-buffered saline, or normal saline, since the peptide is freely soluble in aqueous media and is rarely handled with strong organic solvents. Solution pH should be kept near neutral, because extreme acidity or alkalinity accelerates backbone hydrolysis and encourages oxidation of the methionine side chain. Once dissolved, the material is less stable than the dry powder and is commonly divided into single-use portions and frozen. Buffers containing primary amines, such as Tris, are often avoided because of possible side reactions.
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.
溶液状态的稳定性明显低于冻干粉。肽类在水溶液中可能经历水解、氧化与聚集，其中甲硫氨酸和天冬酰胺等残基常是敏感位点。Semax 含有甲硫氨酸，因此氧化风险相对突出。工作液一般主张现配现用，或冷藏并在数日内用尽。缓冲液种类、pH 和离子强度都会影响降解速率，而关于最佳条件的公开数据并不统一。
常规纯度与身份确认依赖反相高效液相色谱，并辅以质谱测定分子量。氨基酸组成分析可用于验证序列构成，肽图分析则能进一步定位修饰或降解产物。杂质谱通常关注缺失序列肽、截短片段和氧化产物。不同方法的检出限并不相同，因此各实验室报告的纯度数值不宜直接横向比较。
== Oxidative bisulfite sequencing == 5-Methylcytosine and 5-hydroxymethylcytosine both read as a C in bisulfite sequencing. In oxidative bisulfite sequencing (oxBS), Tet is used to convert 5-hydroxymethylcytosine to 5-formylcytosine, which subsequently converts to uracil during bisulfite treatment. The only base that then reads as a C is 5‑methylcytosine, giving a map of the true methylation status in the DNA sample. Levels of 5‑hydroxymethylcytosine can also be quantified by measuring the difference between bisulfite and oxidative bisulfite sequencing. Another method, Tet-assisted oxidative bisulfite sequencing (TAB-Seq) by Chuan He at the University of Chicago, converts the bases differently: 5hmC reads as C, while 5mC and C both read as T. To achieve this, 5hmC bases are first "protected" by conversion to β-glucosyl-5-hydroxymethylcytosine (5gmC). The Tet enzyme is introduced to convert all 5mC to 5caC. Bisulfite then converts both C and 5caC into uracil. 5gmC will be read out like C in PCR amplification.
Formol titration, invented by the Danish chemist S. P. L. Sørensen in 1907, utilizes formaldehyde in the presence of potassium or sodium hydroxide to measure amino acid concentration and ammonia with the aid of a pH meter. The reagents will also react with proline which can give a slightly higher YAN measurement than NOPA. The formol titration method also has the disadvantages of involving the use and disposal of formaldehyde which is a known carcinogen and the highly toxic reagent barium chloride. Ammonia and ammonium can be measured using an ion-selective electrode and a pH meter.
In March 1982, the US implemented an embargo of Libyan oil, and in January 1986 ordered all US companies to cease operating in the country, although several hundred workers remained when the Libyan government doubled their pay. In spring 1986, the US Navy again performed exercises in the Gulf of Sirte; the Libyan military retaliated, but failed as the US sank Libyan ships. Diplomatic relations also broke down with the UK, after Libyan diplomats were accused in the killing of Yvonne Fletcher, a British policewoman stationed outside their London embassy, in April 1984. In 1980, Gaddafi hired former CIA agent Edwin P. Wilson, living in Libya as a fugitive from US justice, to plot the murder of an anti-Gaddafi Libyan graduate student at Colorado State University named Faisal Zagallai. Zagallai was shot in the head in October 1980, in Fort Collins, Colorado by a former Green Beret and associate of Wilson named Eugene Tafoya. Zagallai survived the attack and Tafoya was convicted of third-degree assault and conspiracy to commit assault. Wilson was lured back to the US and sentenced to 32 years due to his ties to Gaddafi. In 1984, Gaddafi publicly executed Al-Sadek Hamed Al-Shuwehdy, an aeronautical engineer studying in the US. After the US accused Libya of orchestrating the 1986 Berlin discotheque bombing, in which two US soldiers died, Reagan decided to retaliate. The CIA was critical of the move, believing Syria was a greater threat and that an attack would strengthen Gaddafi's reputation; however, Libya was recognized as a "soft target".
== Frequency and depth == The depth of penetration depends on the frequency of the microwaves and the tissue type. The Active Denial System ("pain ray") is a less-lethal directed energy weapon that employs a microwave beam at 95 GHz; a two-second burst of the 95 GHz focused beam heats the skin to a temperature of 130 °F (54 °C) at a depth of 1/64th of an inch (0.4 mm) and is claimed to cause skin pain without lasting damage. Conversely, lower frequencies penetrate deeper; at 5.8 GHz (3.2 mm) the depth most of the energy is dissipated in the first millimeter of the skin; the 2.45 GHz frequency microwaves commonly used in microwave ovens can deliver energy deeper into the tissue; the generally accepted value is 17 mm for muscle tissue. As lower frequencies penetrate deeper into the tissue, and as there are fewer nerve endings in deeper-located parts of the body, the effects of the radio frequency waves (and the damage caused) may not be immediately noticeable. The lower frequencies at high power densities present a significant risk. The microwave absorption is directed by the dielectric constant of the tissue. At 2.5 GHz, this ranges from about 5 for adipose tissue to about 56 for cardiac muscle. As the speed of electromagnetic waves is proportional to the reciprocal of the square root of the dielectric constant, the resulting wavelength in the tissue can drop to a fraction of the wavelength in air; e.g. at 10 GHz the wavelength can drop from 3 cm to about 3.4 mm.
Sources: en.wikipedia.org
Very low bodyweight; Rapid weight loss, regardless of starting bodyweight; Medical comorbidities, such as infection or malabsorption; Excessive purging behaviours, including self-induced vomiting, laxative abuse, and diuretic abuse. Two of the most common indicators that RFS is occurring are low phosphate levels and low potassium levels. In these circumstances, it is recommended to start refeeding more slowly but to build up rapidly as long as RFS does not occur. Recommendations on energy requirements in the most medically compromised patients vary, from 5–10 kcal/kg/day to 1900 kcal/day. Treatment professionals must balance the risk of RFS with the risk of underfeeding, which can result in poor health outcomes for short- and long-term recovery.
==== Economic issues ==== In 2010, Larson introduced the Small Business Jobs Act of 2010, authorizing the creation of the Small Business Lending Fund Program administered by the Treasury Department to make capital investments in eligible institutions, in order to increase the availability of credit for small businesses. Larson was a strong advocate for the American Recovery and Reinvestment Act of 2009, which increased federal spending in infrastructure, education, health and energy while expanding some welfare and social security programs. His liberal stance on government spending has earned him a rating of 9% with Citizens Against Government Waste, a conservative anti-government spending interest group.
== Distribution and habitat == Coffee senna is native to the southern United States of America, Mexico and South America, but is an aggressive, pantropical weed. In Australia it is widespread but scattered in the north of Western Australia, the Northern Territory, South Australia, Queensland and New South Wales.
TAAR1 also couples G-protein alpha subunit G13; when triggered by amphetamine, this pathway activates Ras homolog A (RhoA) and its downstream protein kinase, Rho-associated coiled-coil kinase (ROCK), an effect that internalizes both DAT and the neuronal glutamate transporter EAAT3. Transporter internalization via TAAR1's G13-coupled pathway is transient because Gs-cAMP-PKA signaling functionally inhibits RhoA's downstream activity; once intracellular cAMP sufficiently accumulates, PKA is activated and phosphorylates RhoA, thereby terminating ROCK-mediated transporter internalization. In addition to presynaptic actions that regulate DAT, TAAR1 activation exerts a somatodendritic inhibitory influence on midbrain dopamine neurons by reducing their firing rate via G protein-coupled inwardly-rectifying potassium channels, an effect that is expected to reduce action potential-dependent (vesicular) dopamine release into the synaptic cleft. Amphetamine's effect on intracellular calcium is associated with DAT phosphorylation through Ca2+/calmodulin-dependent protein kinase II alpha (CAMKIIα), in turn producing dopamine efflux. Because conventional PKC isoforms can be activated by Ca2+ and diacylglycerol, elevated intracellular calcium can promote PKC-dependent DAT phosphorylation independent of TAAR1.
Many counters have two photo multiplier tubes connected in a coincidence circuit. The coincidence circuit assures that genuine light pulses, which reach both photomultiplier tubes, are counted, while spurious pulses (due to line noise, for example), which would only affect one of the tubes, are ignored. Counting efficiencies under ideal conditions range from about 30% for tritium (a low-energy beta emitter) to nearly 100% for phosphorus-32, a high-energy beta emitter. Some chemical compounds (notably chlorine compounds) and highly colored samples can interfere with the counting process. This interference, known as "quenching", can be overcome through data correction or through careful sample preparation.
Sources: en.wikipedia.org
== Chemistry == The experimental log P of penbutolol is 4.15. Penbutolol showed the second highest predicted lipophilicity of 30 clinically relevant beta blockers, with the most lipophilic beta blocker predicted to be the lesser-known bopindolol.
== Green bean chips == Green bean chips may be prepared mixed with olive oil and seasonings, which are placed on a baking pan and baked until they are crisp. They may be prepared by freeze-drying green beans that are then vacuum-fried. Per a one-ounce (30 g) serving, green bean chips contain 130 calories, 4.5 g fat and 5 g fiber.
=== Generation of pharmaceutical cocrystals === Supercritical fluids act as a new medium for the generation of novel crystalline forms of APIs (Active Pharmaceutical Ingredients) named as pharmaceutical cocrystals. Supercritical fluid technology offers a new platform that allows a single-step generation of particles that are difficult or even impossible to obtain by traditional techniques. The generation of pure and dried new cocrystals (crystalline molecular complexes comprising the API and one or more conformers in the crystal lattice) can be achieved due to unique properties of SCFs by using different supercritical fluid properties: supercritical CO2 solvent power, anti-solvent effect and its atomization enhancement.
== Inhibition of the glyoxylate cycle == Due to the central role of the glyoxylate cycle in the metabolism of pathogenic species including fungi and bacteria, enzymes of the glyoxylate cycle are current inhibition targets for the treatment of diseases. Most reported inhibitors of the glyoxylate cycle target the first enzyme of the cycle (ICL). Inhibitors were reported for Candida albicans for potential use as antifungal agents. The mycobacterial glyoxylate cycle is also being targeted for potential treatments of tuberculosis.
Sources: en.wikipedia.org
Semax is a synthetic seven-amino-acid peptide derived from a fragment of corticotropin. It is used in Russia as a nasal preparation, while elsewhere it is studied as a research compound. It is not approved as a medicine in most countries.
Its sequence corresponds to the 4-10 region of corticotropin extended by three residues. This fragment lacks the region responsible for adrenal steroid release, so it is explored for neural rather than hormonal effects. The relationship explains the compound's classification among ACTH-derived peptides.
It holds approval in Russia for several neurological indications as a nasal spray or drop formulation. Regulatory agencies in the United States and the European Union have not approved it. Products sold elsewhere are generally labeled for research use only.
It is associated with the melanocortin receptor family, particularly subtypes found in the central nervous system. This interaction is separate from the adrenal pathway activated by full-length ACTH.