nasal formulation 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 2025-11-05. Where a claim depends on a specific study, the study is described rather than over-claimed.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its design combines the ACTH(4-7) core fragment with a C-terminal Pro-Gly-Pro extension, a modification intended to improve stability and prolong activity. The molecule is hydrophilic, carries no lipid chains or glycosylation, and has a theoretical mass just over 810 daltons in its free form. All seven residues are proteinogenic amino acids, so no non-natural building blocks appear in the backbone. A free N-terminal methionine and C-terminal proline define the unmodified parent peptide.
The compound was developed during the 1980s at the Institute of Molecular Genetics in Moscow as part of research on fragments of adrenocorticotropic hormone. Early work examined short ACTH-derived sequences that retained neurotrophic effects while lacking the endocrine activity of the full hormone. Semax entered clinical use in Russia during the 1990s, where it received registration for several neurological indications. Outside that region it remained primarily a laboratory research material rather than an approved therapeutic. English-language literature on it grew more slowly and frequently cited the original Russian studies.
Terminology around the compound varies by source. It appears in catalogues and papers as Semax, as the heptapeptide ACTH(4-7)-Pro-Gly-Pro, and under various alphanumeric laboratory codes used by individual suppliers. These names refer to the same sequence but may imply different salt forms, purity grades, or counter-ions. Peptide databases usually list the free base mass, while product descriptions sometimes report acetate or trifluoroacetate salts with a different formula weight. Because naming conventions for research peptides are not standardised across vendors, checking the declared sequence and measured mass is more reliable than relying on a trade name alone.
Purity assessment relies mainly on reversed-phase high-performance liquid chromatography, which separates the target heptapeptide from truncated sequences, deletion analogues, and oxidised forms. Mass spectrometry, usually coupled to liquid chromatography, confirms identity through the expected molecular ion and reveals modifications such as methionine sulfoxide formation. Amino acid analysis can verify composition, and tandem mass spectrometry supports sequence confirmation. Ultraviolet detection near 254 to 280 nanometres is convenient because the phenylalanine and histidine residues absorb in that region. Nuclear magnetic resonance is rarely used for routine release testing.
Common degradation pathways include oxidation of the methionine side chain, hydrolysis of the peptide backbone, and aggregation under unfavourable pH or concentration. Stability studies typically monitor the main peak by chromatography and report total related substances as a percentage. Because no official monograph exists, acceptance criteria vary between laboratories, and reported purity values are not directly comparable across suppliers. Analysts therefore document the method, column, and detection wavelength alongside each result, and open questions remain about how much biological activity the oxidised forms retain.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | ACTH(4-7) analogue |
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Free N terminus, unmodified side chains |
| Molecular weight | 813.9 Da | Free base; salt forms differ |
| Appearance | White to off-white powder | Lyophilised solid |
| Solubility | Freely soluble in water | Hydrophilic; polar solvents preferred |
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.
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.
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。
多数实验室与市售的 Semax 以冻干粉形式提供。冻干粉通常建议保存在 -20 °C 或更低温度下，同时避免光照与反复升温。短期运输有时采用冷藏条件，但长期保存仍以冷冻为主。分包操作应尽量减少开盖次数，以降低吸湿和微生物污染的风险。开封后若未一次用完，建议在干燥环境中密封并尽快放回低温储存。
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.
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.
A more recent application of bone grafting is its use as an antibiotic carrier. Infected bone is poorly perfused, making it difficult to achieve an appropriate antibiotic concentration at the site of infection when intravenous administration is used, especially for antibiotics with large molecules such as vancomycin. In such cases, impacted morcellized bone allografts (IBG), impregnated with local antibiotics can achieve much higher concentrations of antibiotics locally than the minimum inhibitory concentration (MIC).
=== Potassium === Potassium levels can fluctuate severely during the treatment of DKA, because insulin decreases potassium levels in the blood by redistributing it into cells via increased sodium-potassium pump activity. A large part of the shifted extracellular potassium would have been lost in urine because of osmotic diuresis. Hypokalemia (low blood potassium concentration) often follows treatment. This increases the risk of dangerous irregularities in the heart rate. Therefore, continuous observation of the heart rate is recommended, as well as repeated measurement of the potassium levels and addition of potassium to the intravenous fluids once levels fall below 5.3 mmol/L. If potassium levels fall below 3.3 mmol/L, insulin administration may need to be interrupted to allow correction of the hypokalemia.
=== Dendritogenesis === Local interaction of BDNF with the TrkB receptor on a single dendritic segment is able to stimulate an increase in PSD-95 trafficking to other separate dendrites as well as to the synapses of locally stimulated neurons. PSD-95 localizes the actin-remodeling GTPases, Rac and Rho, to synapses through the binding of its PDZ domain to kalirin, increasing the number and size of spines. Thus, BDNF-induced trafficking of PSD-95 to dendrites stimulates actin remodeling and causes dendritic growth in response to BDNF.
Juan Carlos Fuentes, from Venezuela Luis Ramón Amundarain, from Venezuela Eduard Hildalgo, from Venezuela Dushak Milovcic, from Venezuela Robert Sánchez, from Venezuela Jesús Carreño, from Venezuela Eduardo Jaime, from Venezuela Luis Alí Martínez, from Venezuela Alejandro Andrés Carranza Medina, from Colombia Ronald Arregocés, from Colombia Adrián Lino, from Colombia Pedro Ramón Holguín Holguín, from Ecuador Carlos Manuel Rodríguez Solórzano, from Ecuador Chad Joseph, from Trinidad and Tobago Rishi Samaroo, from Trinidad and Tobago Ricky Joseph, from Saint Lucia
Sources: en.wikipedia.org
=== Indolin derivatives === Indolin derivatives on the market are Sunitinib and Intedanib. Two indol derivatives that target the VEGF pathway, semaxanib and sunitinib, have been developed. The former is potent but was inefficient in clinical trials and the latter has many side effects. There is need for a drug with pharmacological effects similar to semaxanib and sunitinib, but it needs to be less toxic. MPEG3-9-semaxanib is semaxanib with an additional water-soluble, non-peptidic oligomer attached to it via a spacer moiety. MPEG3-9-semaxanib derivatives are 10 times more active against VEGFR-2 than sunitinib. Compounds with sunitinib heterocyclic moiety but different amide side chains inhibit VEGFR-1 and VEGFR-2 and regulate disorders. Another compound with sunitinib heterocyclic moiety and a pyrrole side chain has very good VEGFR-2 potency, with an IC50 of 65 nM. N-indol-1-amide compound is a possible anti-tumor drug in combination with other anticancer treatment and has an IC50 value of 31 nM. There are many indol derivatives with different side chains that target multiple kinases and take part in several pathways in tumor development. Intedanib is a multiple tyrosine kinase inhibitor and is the first drug to treat idiopathic pulmonary fibrosis. Indol derivatives with 1-NH of 2-indolinone motif that is an H-bond donor, and 2-carbonyl oxygen that acts as an H-bond acceptor, bind with Glu915 and Cys917, respectively. These compounds have basic amine side chains or nitrogen heterocycles and provide ideal solubility and pharmacokinetics.
== Biosynthesis == In humans, myo-Inositol is synthesized de novo but D-chiro-inositol is not. myo-Inositol is synthesized from glucose 6-phosphate (G6P) in two steps. First, G6P is isomerised by an inositol-3-phosphate synthase enzyme (for example, ISYNA1) to myo-inositol 1-phosphate, which is then dephosphorylated by an inositol monophosphatase enzyme (for example, IMPA1) to give free myo-inositol. In humans, most inositol is synthesized in the kidneys, followed by testicles, typically in amounts of a few grams per day. At the peripheral level, myo-inositol is converted to D-chiro-inositol by a specific epimerase. Only a minor fraction of myo-inositol is converted into D-chiro-inositol. The activity of this epimerase is insulin dependent, causing a reduction of D-chiro-inositol in muscle, fat, and liver when there is insulin resistance. D-chiro-inositol reduces the conversion of testosterone to estrogen, thereby increases the levels of testosterone and worsening PMOS.
In August 2016, Taco Bell brought back its Pink Strawberry Starburst Freeze. In October 2015, Taco Bell launched a certified vegetarian menu. In August 2016, Taco Bell announced it would begin testing a mashup known as Cheetos Burritos at select Taco Bell restaurants On September 19, 2016, Taco Bell launched Airheads Freeze, a drink inspired by the candy Airheads White Mystery, and allow people to guess its flavor on social media. On September 15, 2016, Taco Bell introduced the Cheddar Habanero Quesarito, a quesadilla shelled burrito. In April 2017, Taco Bell announced that it would begin testing the Naked Breakfast Taco in Flint, Michigan in mid-April. The breakfast taco, which uses a fried egg as the shell for potato bites, nacho cheese, shredded cheddar, and bacon or sausage crumble. In 2017, the company released the Naked Chicken Chalupa that uses a chalupa shell made from chicken, using a similar idea to the Double Down and later that year the Naked Chicken Chips, which are chicken nuggets shaped like chips with nacho cheese. In July 2017, Taco Bell announced a partnership with Lyft in which Lyft passengers in Orange County, California, can request "Taco Mode" on their way to their destination from 9 PM to 2 AM, having a stop at Taco Bell. The program was cancelled after much negative feedback from drivers. On September 21, 2018, Taco Bell announced National Taco Day celebrating its global reach outside of the United States, to be celebrated in 20 countries. In January 2019, Taco Bell nearly doubled its television advertising spending to US$64 million.
== Endogenous synthesis == Insulin-like growth factor 1 (IGF-1) is a hormone that is structurally very similar to insulin and mediates the effects of growth hormone (GH) thus affecting metabolism, regeneration, and overall development. The GH-IGF-1 signaling pathway is crucial in the process of vascular remodeling and angiogenesis, i.e., the process of building new blood vessels and thus, helps in maintaining blood circulation in the body. In the brain, IGF-1 is abundant in various cells and regions and research over the years, suggest an imperative role of IGF-1 activity in neurodevelopment making it critical in learning and memory. The IGF-1 family comprises
== Early life and education == In 1974, Eaton graduated from Montana State University with a Bachelor of Science in Pre-Medical Sciences. Under the guidance of Curtis Klaassen and John Doull, he earned a Ph.D. in pharmacology and toxicology at the University of Kansas Medical Center in 1978. In 1979, he joined the faculty at the University of Washington after completing a postdoctoral fellowship in toxicology at the same institution after earning his Ph.D.
Sources: en.wikipedia.org
It is a synthetic seven-amino-acid peptide built from the ACTH(4-7) sequence plus a Pro-Gly-Pro tail. It belongs to the family of short ACTH fragments studied for nervous-system effects. Its backbone contains only standard amino acids.
It contains the 4-7 fragment of adrenocorticotropic hormone extended at the C terminus. That truncation removes the region associated with steroidogenic activity. The design intent was to keep neurotrophic properties while avoiding full hormonal effects.
No natural source of the intact heptapeptide is known. It is produced by solid-phase peptide synthesis. Some related ACTH fragments arise as hormone processing products, but the Pro-Gly-Pro extension is a designed addition rather than a natural sequence.
Dry powder is usually kept at about -20 degrees Celsius for long-term storage and at 2 to 8 degrees Celsius for short working periods. Containers should stay sealed and protected from light and moisture to limit degradation.