If you have been reading about reversed-phase HPLC and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-06-03. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Calculated for the free peptide |
| Molar mass | 813.9 g/mol | Anhydrous free base |
| Peptide class | Synthetic heptapeptide | ACTH(4-10) analogue |
| Parent fragment | ACTH(4-10) | Adrenocorticotropic hormone segment |
| Developmental origin | Institute of Molecular Genetics, Moscow | Work began in the 1980s |
Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead as a research chemical.
Later generations of the molecule include an N-acetylated form and an amidated form, both marketed online alongside the parent peptide. These variants differ in terminal chemistry and stability, and they are frequently discussed in the same breath even though they have not been compared in controlled trials. Supply outside formal healthcare systems comes largely from laboratories that synthesize peptides to order. Purity and identity of these materials vary widely, and no single body oversees the international trade.
Pharmacokinetic accounts emphasize rapid breakdown. After intravenous dosing the intact peptide disappears from blood within minutes, and nasal delivery produces low but measurable concentrations. Metabolites rather than the parent molecule may account for part of the observed activity, although the relative contribution is unresolved. Dosing in the literature varies widely and no optimal schedule has been agreed. These gaps are regularly cited as a reason the findings have not produced broad clinical adoption beyond the original research setting.
Proposed mechanisms center on neurotrophic signaling rather than on classical melanocortin receptor activation. Rodent experiments have reported shifts in the expression of brain-derived neurotrophic factor and nerve growth factor after administration, together with changes in the associated receptor systems. Several authors argue that the peptide acts largely through its degradation products and their interaction with peptidergic pathways, but this remains a hypothesis rather than a settled finding. No single molecular target has been identified in a way that the field broadly accepts.
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.
Identity and purity are established with standard peptide methods. Reversed-phase HPLC with ultraviolet detection near 214 nm resolves the parent peak from deletion and truncation byproducts, and reports typically quote a main-peak percentage. Mass spectrometry by electrospray or MALDI-TOF confirms the expected molecular mass, while amino acid analysis or peptide mapping can verify composition when the sequence itself is in question. A certificate of analysis that pairs a chromatogram with a mass spectrum is more informative than a purity figure alone. Counter-ion content and residual solvents are separate specifications and are frequently omitted.
Semax is normally supplied as a lyophilized powder, and that form is the most stable. Suppliers commonly recommend storage at -20 °C in a desiccated container protected from light, with short-term handling at room temperature limited to weighing and transfer. Powder that has absorbed moisture degrades faster, so vials should be warmed to ambient temperature before opening to prevent condensation on the contents. Hygroscopic behavior is typical of short hydrophilic peptides, and humidity control matters more than temperature alone for long-term retention.
Once dissolved, the peptide is considerably less stable than the solid. Aqueous solutions are usually prepared at neutral to slightly acidic pH, filtered, and divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are a common cause of avoidable loss and are best prevented by never refreezing a thawed aliquot. Adsorption to plastic and glass surfaces can lower the measured concentration of dilute solutions, particularly below roughly 0.1 mg/mL. Buffer choice, salt content, and container material all influence how much peptide remains detectable after storage.
Another Half-Life 2 episode was developed by Junction Point Studios, led by Warren Spector. The episode showed how the town of Ravenholm from Half-Life 2 became infested with headcrabs and zombies, with the return of the character of Father Grigori. It included a "magnet gun", which fired projectiles that magnetized metal surfaces and attracted objects and enemies, and was used for combat and puzzles. Junction Point worked on the game for a year, producing enough content to demonstrate one section, and a vertical slice that demonstrated the magnet gun. Valve lost interest in the project and Junction Point, who had been acquired by Disney Interactive Studios partway through, canceled it to instead develop Epic Mickey. Screenshots appeared in early 2017.
=== Chemistry of hydrogen exchange === One of the major complications in studying hydrogen isotopes is the issue of exchangeability. At many time scales, ranging from hours to geological epochs, scientists have to consider if the hydrogen moieties in studied molecules are the original species or if they represent exchange with water or mineral hydrogen near by. Research in this area is still inconclusive in regards to rates of exchange, but it is generally understood that hydrogen exchange complicates the preservation of information in isotope studies.
A low-sulfur diet is a diet with reduced sulfur content. Important dietary sources of sulfur and sulfur containing compounds may be classified as essential mineral (e.g. elemental sulfur), essential amino acid (methionine) and semi-essential amino acid (e.g. cysteine). Sulfur is an essential dietary mineral primarily because amino acids contain it. Sulfur is thus considered fundamentally important to human health, and conditions such as nitrogen imbalance and protein-energy malnutrition may result from deficiency. Methionine cannot be synthesized by humans, and cysteine synthesis requires a steady supply of sulfur.
=== Affinity chromatography === Affinity chromatography is a method of separating biochemical mixtures, based on a highly specific biologic interaction such as that between antigen and antibody, enzyme and substrate, or receptor and ligand. The method was subsequently adopted for a variety of other techniques. Specific uses of affinity chromatography include antibody affinity, Immobilized metal ion affinity chromatography and purification of recombinant proteins - possibly the most common use of the method. To purify, proteins are tagged e.g. using His-tags or GST (glutathione-S-transferase) tags, which can be recognized by a metal ion ligand, such as imidazole. In 1971, Wilchek and colleagues applied this method to show that protein kinase is composed of regulatory and catalytic subunits. In 1972, Wilchek showed that the method can be used to remove toxic compounds from blood, as exemplified by the removal of heme peptides from blood using immobilized human serum albumin, thus laying the grounds for modern hemoperfusion
Reptiles were traditionally considered less intelligent on average than mammals and birds, but this is increasingly suspected to be the result of poor methodologies in past research and overreliance on brain size as indicators of intelligence rather than a genuine trait of reptiles. The size of their brain relative to their body is much less than that of mammals, the encephalization quotient being about one tenth of that of mammals, though larger reptiles can show more complex brain development. Larger lizards, like the monitors, are known to exhibit complex behavior, including cooperation and cognitive abilities allowing them to optimize their foraging and territoriality over time. Crocodiles have relatively larger brains and show a fairly complex social structure. The Komodo dragon is even known to engage in play, as are turtles, which are also considered to be social creatures, and sometimes switch between monogamy and promiscuity in their sexual behavior. One study found that wood turtles were better than white rats at learning to navigate mazes. Another study found that giant tortoises are capable of learning through operant conditioning, visual discrimination and retained learned behaviors with long-term memory. Sea turtles have been regarded as having simple brains, but their flippers are used for a variety of foraging tasks (holding, bracing, corralling) in common with marine mammals. There is evidence that reptiles are sentient and able to feel emotions including anxiety and pleasure.
Sources: en.wikipedia.org
It has a Ki of over 10,000 nM (and thus negligible affinity) for β-adrenergic, H1, and mACh. Toxicity depends on the route of administration; the LD50s in mice were 300 mg/kg for the oral route, 160 mg/kg for intraperitoneal, and 56 mg/kg intravenous.
=== Overexpression in cancers === CUX1 is overexpressed in many cancers. The comprehensive molecular characterization of human colon and rectal cancer performed by The Cancer Genome Atlas (TCGA) ranked CUX1 as the fifth gene on a scale showing a correlation between tumour aggressiveness and gene expression/somatic copy number alterations. TCGA and REMBRANDT data also show shorter survival of glioblastoma patients with high CUX1 mRNA expression (reviewed). In smaller scale studies, immunohistochemical analyses on breast, pancreas and glioblastoma cancers reveal that CUX1 expression inversely correlates with relapse-free and overall survival. An alternative CUX1 transcript that is initiated within intron 20 and codes for a p75 isoform is expressed specifically in the testis and thymus. This transcript was found to be aberrantly expressed in many breast tumour cells lines and breast tumours. Transgenic mice expressing this transcript in mammary epithelial cells were shown to develop mammary tumours with metastasis to the lung.
==== Growth hormone receptor antagonists ==== The latest development in the medical treatment of acromegaly is the use of growth hormone receptor antagonists. The only available member of this family is pegvisomant (Somavert). By blocking the action of the endogenous growth hormone molecules, this compound is able to control the disease activity of acromegaly in virtually everyone with acromegaly. Pegvisomant has to be administered subcutaneously by daily injections. Combinations of long-acting somatostatin analogues and weekly injections of pegvisomant seem to be equally effective as daily injections of pegvisomant. Paltusotine (Palsonify) was approved for medical use in the United States in September 2025.
== Function == PPARG regulates fatty acid storage and glucose metabolism. The genes activated by PPARG stimulate lipid uptake and adipogenesis by fat cells. PPARG knockout mice are devoid of adipose tissue, establishing PPARG as a master regulator of adipocyte differentiation. PPARG increases insulin sensitivity by enhancing storage of fatty acids in fat cells (reducing lipotoxicity), by enhancing adiponectin release from fat cells, by inducing FGF21, and by enhancing nicotinic acid adenine dinucleotide phosphate production through upregulation of the CD38 enzyme in mice. PPARG promotes anti-inflammatory M2 macrophage activation in mice. Adiponectin induces ABCA1-mediated reverse cholesterol transport by activation of PPAR-γ and LXRα/β. Many naturally occurring agents directly bind with and activate PPAR gamma. These agents include various polyunsaturated fatty acids like arachidonic acid and arachidonic acid metabolites such as certain members of the 5-hydroxyicosatetraenoic acid and 5-oxo-eicosatetraenoic acid family, e.g., 5-oxo-15(S)-HETE and 5-oxo-ETE or 15-hydroxyicosatetraenoic acid family including 15(S)-HETE, 15(R)-HETE, and 15(S)-HpETE, the phytocannabinoid tetrahydrocannabinol (THC), its metabolite THC-COOH, and its synthetic analog ajulemic acid (AJA). The activation of PPAR gamma by these and other ligands may be responsible for inhibiting the growth of cultured human breast, gastric, lung, prostate and other cancer cell lines. During embryogenesis, PPARG first substantially expresses in the interscapular brown fat pad in mice.
Sources: en.wikipedia.org
==== Effects ==== In contrast to amphetamines like (–)-cathinone, but similarly to mescaline, DOM has shown no stimulant-like or reinforcing effects in rhesus monkeys. Conversely however, DOC has shown reinforcing effects, including conditioned place preference (CPP) and self-administration, in rodents similarly to methamphetamine. This is analogous to other findings in which various 2C and NBOMe drugs have been found to produce brain dopaminergic elevations and reinforcing effects in rodents.
The United States Food and Drug Administration and the European Medicines Agency have approved weight loss medications for adults with either a body-mass index (BMI) of at least 30, or a body-mass index of at least 27 with at least one weight-related comorbidity. This patient population is considered to have sufficiently high baseline health risks to justify the use of anti-obesity medication. The American Academy of Pediatrics had not previously supported the use of weight loss medication in adolescents but issued new guidelines in 2023, which recommend considering the use of weight loss medication in some overweight children aged 12 or older. The European Medicines Agency has approved semaglutide for children aged 12 or older who have a BMI in the 95 percentile for their age and a weight of at least 60 kilograms (130 lb). However, GLP-1 agonists may not be cost effective in this population.
During the 2015 high school football season, Kuper was an offensive line coach at Columbine High School in Littleton, Colorado. On January 23, 2016, Kuper was hired by Miami Dolphins as offensive quality control coach. He then spent two seasons (2017–18) as the assistant offensive line coach for Miami. On January 22, 2019, the Denver Broncos hired Kuper as their assistant offensive line coach. With the firing of Vic Fangio from the Broncos, Kuper was hired by Kevin O'Connell to be the offensive line coach for the Minnesota Vikings. Before the 2026 season, his contract expired and the Vikings chose not to retain him. On February 9, 2026, the Philadelphia Eagles hired Kuper as their new offensive line coach. Eagles offensive coordinator Sean Mannion previously played for the Minnesota Vikings at the end of his playing career, during which Kuper served as the Vikings offensive line coach. UND Football bio Denver Broncos bio Kuper not letting broken right hand block opportunity
6 CO2 + 6 H2O → C6H12O6 + 6 O2 For example, large blooms of plankton (free-floating organisms) absorb large amounts of 12C from the oceans. Originally, the 12C was mostly incorporated into the seawater from the atmosphere. If the oceans that the plankton live in are stratified (meaning that there are layers of warm water near the top, and colder water deeper down), then the surface water does not mix very much with the deeper waters, so that when the plankton dies, it sinks and takes away 12C from the surface, leaving the surface layers relatively rich in 13C. Where cold waters well up from the depths (such as in the North Atlantic), the water carries 12C back up with it; when the ocean was less stratified than today, there was much more 12C in the skeletons of surface-dwelling species. Other indicators of past climate include the presence of tropical species and coral growth rings.
=== Mandatory minimums === The Anti-Drug Abuse Act of 1986 established a 100-1 sentencing disparity for the possession of crack or powder cocaine. Possession of 500 g of powder cocaine triggered a five-year mandatory minimum sentence, but it took possession of 5 g of crack cocaine to trigger the same mandatory minimum penalty. In addition, the Anti-Drug Abuse Act of 1988 established a one-year mandatory minimum penalty for simple possession of crack cocaine, which made crack cocaine the only controlled substance for which a first possession offense triggered a mandatory minimum penalty. A 1992 study found that mandatory minimum sentencing caused blacks and Hispanics to receive more-severe sentences than their white counterparts from 1984 to 1990. In 1995, the United States Sentencing Commission delivered a report to Congress concluding that because 80% of crack offenders were black, the 100–1 disparity disproportionately affected minorities. It recommended for the crack-powder sentencing ratio to be amended, and other sentencing guidelines to be re-evaluated. Its recommendations were rejected by Congress. By contrast, certain authors have pointed out that the Congressional Black Caucus backed the Anti-Drug Abuse Act of 1986, which implied that that law could not be racist. In 2010, Congress passed the Fair Sentencing Act, which reduced the sentencing disparity between crack and powder cocaine from 100–1 to 18–1. The mandatory minimum penalty was amended to take effect for possession of crack cocaine in excess of 28 g.
Sources: en.wikipedia.org
Semax is based on the ACTH(4-10) fragment, a seven-amino-acid segment of adrenocorticotropic hormone. The synthetic peptide retains the core sequence while removing regions associated with endocrine activity. This modification is intended to isolate effects on the nervous system.
It is registered for clinical use in Russia and a few other countries, typically as a nasal drop formulation. It does not hold approval from the United States Food and Drug Administration or the European Medicines Agency. Outside those markets it is generally handled as a research chemical.
The compound was developed in Moscow and the earliest studies were conducted there, so the primary literature is largely in Russian-language journals. Translation and indexing have been incomplete, which limits access for outside researchers. Independent groups have since published some work, but the total volume remains modest.
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.