intranasal delivery 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 2026-01-11. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Published research covers ischemic stroke, traumatic brain injury, cognitive impairment, optic nerve conditions and attention-related measures. Much of the human evidence comes from small trials conducted in one country, which limits how far the results generalize. Animal models supply the larger share of the data, and effects seen in rodents do not transfer automatically to people. Reviews have noted that methodological reporting is often incomplete, making it difficult to pool results or compare treatment schedules across studies.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Seven-residue peptide |
| Molecular mass | 813.9 Da | Monoisotopic value |
| Appearance | White to off-white powder | Lyophilized form |
| Solubility | Freely soluble in water | Also soluble in saline and polar solvents |
| Storage (dry) | -20 °C or lower | Desiccated, protected from light |
研究兴趣主要集中在神经营养因子相关的路径上，包括脑源性神经营养因子与神经生长因子的表达变化。部分实验报告称在特定条件下观察到这些因子的水平上升，但具体信号通路和剂量依赖关系仍未完全厘清。多数公开数据来自细胞模型和动物实验，人体对照研究数量有限。因此，该化合物的作用机制在文献中属于活跃讨论，而非已经确立的定论。
Semax 是一种人工合成的七肽，氨基酸序列为 Met-Glu-His-Phe-Pro-Gly-Pro，单字母缩写记作 MEHFPGP。它被归类为促肾上腺皮质激素片段 ACTH(4-10) 的结构类似物，但并不天然存在于生物体内。母体片段 ACTH(4-10) 的序列为 Met-Glu-His-Phe-Arg-Trp-Gly，Semax 替换了中间两个残基，并在羧基端延长了 Pro-Gly-Pro 三肽。这种延长被普遍认为能提升分子对肽酶的耐受性。
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.
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.
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.
The C-terminal Pro-Gly-Pro extension is not incidental. Proline-rich tails are known to resist several common peptidases, and the published literature attributes the longer half-life of Semax, relative to unmodified ACTH fragments, to this feature. The modification also removes the melanocyte-stimulating and corticosteroidogenic activity that characterizes longer ACTH-derived sequences. Because the molecule is small and hydrophilic, it is typically formulated as an aqueous solution for intranasal or parenteral delivery. Acetylation or amidation at the termini appears in closely related research peptides and shifts the mass by a fixed increment.
=== Paramount and CBS partnership === On August 11, 2025, the UFC announced a seven-year media rights agreement with Paramount Skydance Corporation worth $7.7 billion. Paramount+ will exclusively stream all events for seven years, starting in 2026. Some numbered events will also air on CBS. The agreement will allow the UFC to move away from pay-per-view as events will stream on Paramount+ at no additional cost. All 13 of the UFC's flagship events and 30 Fight Nights a year will be streamed on the Paramount+ service. UFC CEO and President Dana White announced the UFC would produce four big events per year on CBS, and that the UFC's planned card for the White House on June 14th, 2026 would be one of those events.
== See also == Bioluminescence imaging Gene expression Gene knock-in Gene regulatory network GUS reporter system Molecular cloning Promoter (genetics) Selectable marker Synthetic biology Transcription factor Transfection
=== Fibroblast growth factor === fibroblast growth factor (FGF-21) has been recently characterized as a potent metabolic regulator. Systemic administration of FGF-21 reduced plasma glucose and triglycerides to near normal levels in genetically compromised diabetic rodents. FGF21 can function as a crucial regulator mediating beneficial metabolic effects of therapeutic agents such as metformin, glucagon/glucagonlike peptide1analogues, thiazolidinedione, sirtuin 1 activators, and lipoic acid. A study showed that when fibroblast growth factor-21 administered daily for 6 weeks to diabetic rhesus monkeys, it caused a dramatic decline in fasting plasma glucose, fructosamine, triglycerides, insulin and glucagon. In a significant point during the study, FGF-21 administration also led to significant improvements in lipoprotein profiles and a beneficial changes in the circulating levels of several cardiovascular risk markers. And the induction of a small but significant weight loss. These data support the development of FGF-21 for the treatment of diabetes and other metabolic diseases.
== Biography == Yourcenar was born in Brussels, Belgium, as Marguerite Antoinette Jeanne Marie Ghislaine Cleenewerck de Crayencour, to Michel Cleenewerck de Crayencour and Fernande de Cartier de Marchienne. Her father was of French bourgeois descent, originating from French Flanders, and a wealthy landowner. Her mother, of Belgian nobility, died ten days after Marguerite's birth. She grew up in the home of her paternal grandmother, and adopted the surname Yourcenar as a pen name; in 1947, she also took it as her legal surname. Yourcenar's first novel, Alexis, was published in 1929. She translated Virginia Woolf's The Waves over a ten-month period in 1937. In 1939, her partner at the time, the literary scholar and Kansas City native Grace Frick, invited Yourcenar to the United States to escape the outbreak of World War II in Europe. She lectured in comparative literature in New York City and Sarah Lawrence College. Yourcenar and Frick became lovers in 1937 and remained together until Frick's death in 1979. After ten years spent in Hartford, Connecticut, they bought a house in Northeast Harbor, Maine, on Mount Desert Island, where they lived for decades. They are buried next to each other at Brookside Cemetery, Somesville, Mount Desert, Maine. Yourcenar's last companion was Jerry Wilson, with whom she had a tormented relationship; he died of AIDS in 1986. In 1951, Yourcenar published, in France, the novel Memoirs of Hadrian, which she had been writing on and off for a decade. The novel was an immediate success and met with critical acclaim.
Sources: en.wikipedia.org
In other words, if two people receive the same dose of a given drug based on BSA, the concentration of that drug in the bloodstream of one person may be 10 times higher or lower compared to that of the other person. This variability is typical with many chemotherapy drugs dosed by BSA, and, as shown below, was demonstrated in a study of 14 common chemotherapy drugs.
The underlined nucleotides indicate the translation start codon, coding for Methionine. upper-case letters indicate highly conserved bases, i.e. the 'AUGG' sequence is constant or rarely, if ever, changes. 'R' indicates that a purine (adenine or guanine) is always observed at this position (with adenine being more frequent according to Kozak) a lower-case letter denotes the most common base at a position where the base can nevertheless vary the sequence in parentheses (gcc) is of uncertain significance. The AUG is the initiation codon encoding a methionine amino acid at the N-terminus of the protein. (Rarely, GUG is used as an initiation codon, but methionine is still the first amino acid as it is the met-tRNA in the initiation complex that binds to the mRNA). Variation within the Kozak sequence alters the "strength" thereof. Kozak sequence strength refers to the favorability of initiation, affecting how much protein is synthesized from a given mRNA. The A nucleotide of the "AUG" is delineated as +1 in mRNA sequences with the preceding base being labeled as −1, i.e. there is no 0 position. For a 'strong' consensus, the nucleotides at positions +4 (i.e. G in the consensus) and −3 (i.e. either A or G in the consensus) relative to the +1 nucleotide must both match the consensus. An 'adequate' consensus has only 1 of these sites, while a 'weak' consensus has neither. The cc at −1 and −2 are not as conserved, but contribute to the overall strength. There is also evidence that a G in the -6 position is important in the initiation of translation.
=== Pregnancy === No antidepressants are FDA approved during pregnancy. Use of antidepressants during pregnancy may result in fetus abnormalities affecting functional development of the brain and behavior. Studies have shown correlations between pregnant women treated with SNRIs and risk of hypertensive disorders, preeclampsia, miscarriage, seizures in children, and many other adverse affects.
== Technology == The humanized monoclonal antibody is stochastically conjugated via a valine-alanine cleavable, maleimide linker to a cytotoxic (anticancer) pyrrolobenzodiazepine (PBD) dimer. The antibody binds to CD19, a protein which is highly expressed on the surface of B-cell hematological tumors including certain forms of lymphomas and leukemias. After binding to the tumor cells the antibody is internalized, the cytotoxic drug PBD is released and the cancer cells are killed. PBD dimers are generated out of PBD monomers, a class of natural products produced by various actinomycetes. PBD dimers work by crosslinking specific sites of the DNA, blocking the cancer cells’ division that cause the cells to die. As a class of DNA-crosslinking agents they are significantly more potent than systemic chemotherapeutic drugs.
Thus, when the neuron is at a depolarized membrane potential, polyamines will block the AMPAR channel more strongly, preventing the flux of potassium ions through the channel pore. GluA2-lacking AMPARs are, thus, said to have an inwardly rectifying I/V curve, which means that they pass less outward current than inward current at equivalent distance from the reversal potential. Calcium permeable AMPARs are found typically early during postnatal development on neocortical pyramidal neurons, some interneurons, or in dopamine neurons of the ventral tegmental area after the exposure to an addictive drug. Alongside RNA editing, alternative splicing allows a range of functional AMPA receptor subunits beyond what is encoded in the genome. In other words, although one gene (GRIA1–GRIA4) is encoded for each subunit (GluA1–GluA4), splicing after transcription from DNA allows some exons to be translated interchangeably, leading to several functionally different subunits from each gene. The flip/flop sequence is one such interchangeable exon. A 38-amino acid sequence found prior to (i.e., before the N-terminus of) the fourth membranous domain in all four AMPAR subunits, it determines the speed of desensitization of the receptor and also the speed at which the receptor is resensitized and the rate of channel closing. The flip form is present in prenatal AMPA receptors and gives a sustained current in response to glutamate activation.
Sources: en.wikipedia.org
==== Second state of emergency: June 1986 ==== The partial emergency was lifted on 7 March 1986, only to be replaced on 12 June – in the run-up to the tenth anniversary of the Soweto uprising on 16 June – by a second, far more stringent state of emergency, now applying across the country. Among other things, the new order empowered any member of the police or army to use any kind of force deemed necessary to clear an area. With the death toll by then "far in excess of 1,600", Botha told Parliament, "I am of the opinion that the ordinary laws of the land at present on the statute book are inadequate to enable the government to insure the security of the public and to maintain public order". The government said that it detained more than 1,000 people on the first day of the emergency; 30,000 were detained by August 1987. Indeed, the primary use of the emergency orders was to enable mass and indefinite detention of those viewed by the government as the ringleaders or instigators of the unrest. Critics of the government argued that this was deeply counterproductive, as the putative ringleaders were generally "simply the most articulate and experienced activists", the removal of whom "created a political vacuum into which unruly, undisciplined elements surged". In the phrase of the UDF's Murphy Morobe (speaking to press while in hiding to evade arrest), "Removing responsible leaders of the people has effectively paved the way for a blood bath". Desmond Tutu lamented as early as May 1986 that the government "have arrested the very people they should be talking to...
=== Mechanism behind Neurotoxic Properties === Versutoxin, in particular, is capable of affecting the voltage-gated sodium channels of prey. Studies conducted on primates show that δ-hexatoxin causes the neurotoxic effects by binding to VGSCs on neurons. δ-ACTX affects VGSCs similarly to α-scorpion and sea anemone toxins. Both of these types of toxins bind specifically to site 3 on the sodium channel. Despite versutoxin having a ICK which both α-scorpion and sea anemone toxins lack, researchers determined several other similarities in their anionic and cationic residue topography and confirmed that versutoxin also binds to site 3. They tested this by seeing how purified delta-ACTX-Hv1a affects the isolated cockroach (Periplaneta americana) dorsal unpaired median (DUM) neurons using a double sucrose-gap technique and comparing it to how it affected rat dorsal root ganglion (DRGs) neurons. They noted how delta-ACTX-Hv1a specifically affected voltage-gated Na+ channels of both specimens resulting in incomplete steady-state Na+ channel inactivation.
In order to reach the maximum efficacy to eradicate biofilms, therapeutic strategies need to target both the biofilm matrix components as well as the embedded microorganisms to target the complex biofilm microenvironment.
== Prevention of passing on scabies to other people == Mass-treatment programs that use topical permethrin or oral ivermectin have been effective in reducing the prevalence of scabies in several populations. The simultaneous treatment of all close contacts is recommended, even if they show no symptoms of infection (asymptomatic), to reduce rates of recurrence. Since mites can survive for only two to three days without a host, other objects in the environment pose little risk of transmission except in the case of crusted scabies. Therefore, cleaning is of little importance. Rooms used by those with crusted scabies require thorough cleaning.
Sources: en.wikipedia.org
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.
The extension was introduced to slow enzymatic breakdown of the peptide in biological systems. Natural ACTH fragments are degraded rapidly by peptidases. Adding the tripeptide was intended to extend the window during which the molecule remains intact.
Most published work consists of animal experiments conducted in a small number of laboratories. Human data are limited in number and size. Whether the observed effects translate into reliable clinical benefit is still unresolved.
The main proposal is modulation of neurotrophic factors such as brain-derived neurotrophic factor, supported largely by animal experiments. Receptor-level targets have not been firmly established. Most reviews describe the mechanism as only partially characterized.