ACTH(4-10) 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.
Updated 2026-08-01. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Development is attributed to researchers at the Institute of Molecular Genetics in Moscow during the early 1980s, building on earlier Soviet work with ACTH fragments. Russian regulatory approval followed for intranasal use, and the compound has remained commercially available there for decades. Most published human data originate from Russian and, later, some Eastern European clinical reports, which are not always accessible in English translation. Outside that region the material is generally handled as a research chemical rather than a licensed medicine.
Verification of a supplied batch generally combines a certificate of analysis with independent testing, because certificates are self-reported documents. A typical package includes a chromatographic trace, a mass spectrum, and a stated water or counter-ion content. Batch-to-batch consistency matters more than a single purity figure when results are compared across experiments. No single mandatory standard governs research-grade peptide release, so laboratories are expected to define their own acceptance criteria. Residual trifluoroacetate from purification is a frequently overlooked counter-ion.
Lyophilized material is chemically stable for extended periods when kept dry, cold, and protected from light. The powder is hygroscopic, so vials should be warmed to room temperature before opening to reduce condensation on the contents. Once dissolved, the peptide is far less stable because peptide bonds are susceptible to hydrolysis and the methionine residue can oxidize. Solutions are typically aliquoted and held at 2-8 °C for short intervals or frozen for longer ones, and repeated freeze-thaw cycles should be avoided.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide (ACTH fragment analog) | Not a steroid; does not belong to the melanocortin agonist drugs by marketing category |
| Molecular formula | C37H51N9O10S (commonly cited) | Reported values vary slightly with salt and counter-ion content |
| Appearance | White to off-white lyophilized powder | A single batch may appear as a loose cake or fluffy solid |
| Solubility | Freely soluble in water and aqueous buffer | Stock solutions are usually prepared in sterile water or saline |
| Typical storage | −20 °C or below, desiccated and protected from light | Seal opened vials promptly to limit moisture uptake |
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.
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.
Lyophilised powder is normally kept at -20 °C in a desiccated container, with some suppliers recommending -80 °C for long-term archival storage. Repeated freeze-thaw cycles are the most common cause of avoidable loss, so aliquoting before freezing reduces variability between working sessions. Dissolved peptide is far less stable than the dry solid and is usually prepared fresh or held briefly at 4 °C. Aqueous solutions support both hydrolysis of the backbone and oxidation of the N-terminal methionine, and these two routes dominate degradation under ordinary laboratory conditions.
Identity and purity are confirmed with reversed-phase high-performance liquid chromatography, typically monitored at 214 nanometres where the peptide bond absorbs. Mass spectrometry, either electrospray or MALDI-TOF, verifies molecular mass against the theoretical value and detects truncation or adduct formation. Amino acid analysis and peptide mapping provide additional confirmation when required. The most frequently reported impurities are deletion sequences from incomplete coupling, methionine sulfoxide from oxidation, and dimeric species formed through non-covalent aggregation. Impurity profiles depend strongly on the synthesis and purification route chosen by the producer.
The current NIOSH definition for an IDLH condition, as given in the NIOSH Respirator Selection Logic, is one that poses a threat of exposure to airborne contaminants when that exposure is likely to cause death or immediate or delayed permanent adverse health effects or prevent escape from such an environment. The purpose of establishing an IDLH value is (1) to ensure that the worker can escape from a given contaminated environment in the event of failure of the respiratory protection equipment and (2) is considered a maximum level above which only a highly reliable breathing apparatus providing maximum worker protection is permitted. In September 1995, NIOSH issued a new policy for developing recommended exposure limits (RELs) for substances, including carcinogens. As benzene can cause cancer, NIOSH recommends that all workers wear special breathing equipment when they are likely to be exposed to benzene at levels exceeding the REL (10-hour) of 0.1 ppm. The NIOSH short-term exposure limit (STEL – 15 min) is 1 ppm. American Conference of Governmental Industrial Hygienists (ACGIH) adopted Threshold Limit Values (TLVs) for benzene at 0.02 ppm TWA in 2024. The European Union exposure limit value for benzene is 0.66 mg/m3. Germany's acceptable concentration (AC) is 0.2 mg/m3 and tolerable concentration (TC) is 1.9 mg/m3, where 1 mg/m3 is about 1 ppm in air.
=== Multiple turns === In many cases, one or more residues are involved in two partially overlapping turns. For example, in a sequence of 5 residues, both residues 1 to 4 and residues 2 to 5 form a turn; in such a case, one speaks of an (i, i + 1) double turn. Multiple turns (up to sevenfold) occur commonly in proteins. Beta bend ribbons are a different type of multiple turn. Multiple types of short H-bonded loop motifs are composed of overlapping H-bonded turns of the same or different types (lengths), including the Schellman loop and its variants, the multiple types of the beta bulge loop, and others. These motifs, which play key roles in proteins, including as helix caps, chain-reversers in beta hairpins and ligand binders, have been described as "compound turns" and classified using a compact notation that specifies the types and start positions in the loop of each motif's turns. The ExploreTurns tool supports the exploration and analysis of these motifs. The tool may also be used to explore individual H-bonded turns of all types.
== Use and effects == In his book PiHKAL (Phenethylamines I Have Known and Loved) and other publications, Alexander Shulgin lists 3,4-DMA's dose as "a few hundred milligrams" (route unspecified) and its duration as unknown. A dose of approximately 70 mg intravenously produced insignificant to slight psychoactive effects in two individuals. Conversely, a subsequent approximate 700 mg dose intravenously in the same two people produced a definite mescaline-like state, including visual hallucinations (e.g., geometric figures and occasional structured forms), visual distortions, after-images, feelings of unreality, paranoia, marked pupil dilation, and gross body tremors. Gordon Alles reported 3,4-DMA to be inactive at doses of 10 to 120 mg orally but active at 160 mg orally, with reported effects including increased blood pressure, slight pupil dilation, lacrimation, and gastrointestinal uneasiness. He estimated that the response at this dose was equivalent to that of about 60 to 80 mg 3,4-methylenedioxyamphetamine (MDA), suggesting that 3,4-DMA's potency may be about 2- to 3-fold lower than that of MDA and may fall midway between that of MDA and mescaline. Alternatively, according to Shulgin, 3,4-DMA may have comparable potency to mescaline, with an effective dose of perhaps 300 to 400 mg orally, or may be less potent than mescaline. Richard Glennon suggested that the dose may be 400 to 700 mg orally.
Adipocyte protein 2 (aP2) is a carrier protein for fatty acids that is primarily expressed in adipocytes and macrophages. aP2 is also called fatty acid binding protein 4 (FABP4). Blocking this protein either through genetic engineering or drugs has the possibility of treating heart disease and the metabolic syndrome.
== Change of properties with temperature == All materials change with temperature, but superheated water exhibits greater changes than would be expected from temperature considerations alone. Viscosity and surface tension of water drop and diffusivity increases with increasing temperature.
Sources: en.wikipedia.org
=== Drug design of RXPA 380 === RXPA380 was the first inhibitor that was highly selective of the C-domain of ACE, it has the formula Phe-Phe-Pro-Trp. The development of this compound was built on researches that showed that some bradykinin-potentiating peptides showed selectivity for the C-domain and all had several prolines in their structure. These observations lead the researchers to synthesize phosphinic peptides containing a proline residue in the P1’ position and evaluating these compounds led to the discovery of RXPA380. To study the roles of the residues on RXPA380 the researchers made 7 analogues of RXPA380. All of the compounds made were obtained as a mixture of either 2 or 4 diastereoisomers but all of them were easily resolved and only one of them was potent. This is consistent with the initial modeling studies of RXPA380 which showed that only one diastereomer could accommodate in the active site of germinal ACE. Analogues where pseudo-proline or tryptophan residues had been substituted showed less selectivity than RXPA380. This is probably because these two analogues have more potency toward the N-domain than RXPA380 does. Substituting both of these residues gives great potency but none selectivity. This shows that pseudo-proline and tryptophan residues accommodate well in the C-domain but not in the N-domain. Two more analogues with both pseudo-proline and tryptophan but missing the pseudo-phenylalanine residue in P1 position showed low potency for N-domain, similar to RXPA380.
== Function == In most fish species, barbels are used to aid in the acquisition of food in bodies of water that have low visibility due to low light conditions or murky waters. The taste receptors are able to detect enzymes in the water and help the fish identify if it is from a possible food source or possible sources of danger. The abyssal zone scavengers Coryphaenoides armatus possess one small mandible barbel that they use to search the seafloor for carrion to eat. Freckled Goatfish, Upeneus tragula, develop barbels as a response to food availability. When starved of food for two days under laboratory conditions, U. tragula develop large barbels compared to those developed by those who were fed consistently. The large barbels help the organism capture prey and compete against other individuals. However, individuals that developed large barbels also experienced a decreased growth rate. In the species Triportheus signatus, individuals have been found to develop barbels late in life as a response to low dissolved oxygen in pools left after flood waters recede following the rainy season. These structures are more vascularized than barbels of other fish species to help gas exchange in low oxygen conditions and direct more water flow over the gills.
Male sex Plus three of the following in the first two years of disease: Erythrocyte sedimentation rate (ESR) >30 mm/h Unresponsive to NSAIDs Limitation of lumbar spine range of motion Sausage-like fingers or toes Oligoarthritis Onset <16 years old
Singer noted in 1949 that Psilocybe cubensis had psychoactive properties. In Australia, the use of psychoactive mushrooms grew rapidly between 1969 and 1975. In a 1992 paper, locals and tourists in Thailand were reported to consume P. cubensis and related species in mushroom omelets—particularly in Ko Samui and Ko Pha-ngan. At times, omelets were adulterated with LSD, resulting in prolonged intoxication. A thriving subculture had developed in the region. Other localities, such as Hat Yai, Ko Samet, and Chiang Mai, also had some reported usage. In 1996, jars of honey containing Psilocybe cubensis were confiscated at the Dutch-German border. Upon examination, it was revealed that jars of honey containing psychedelic mushrooms were being sold at Dutch coffee shops. P. cubensis is one of the most widely known of the psilocybin-containing mushrooms used for triggering psychedelic experiences after ingestion. Its major alkaloids are:
Sources: en.wikipedia.org
It is a short synthetic peptide built from seven amino acids: methionine, glutamic acid, histidine, phenylalanine and three prolines. The sequence derives from the 4-10 fragment of adrenocorticotropic hormone with an added proline-glycine-proline tail. No plant or animal extract is involved; the material is produced by solid-phase peptide synthesis.
It was developed in the Soviet Union during the early 1980s by groups at the Institute of Molecular Genetics in Moscow. Russian approval for intranasal use followed, and it has been marketed there since. Western laboratories encountered it mainly through translated literature and, later, through online research-chemical trade.
It holds a Russian registration as a prescription nasal product but has no approval from the European Medicines Agency or the United States Food and Drug Administration. Buyers outside Russia usually receive material sold strictly for laboratory research. That distinction matters because research-grade and pharmaceutical-grade products carry different documentation and testing expectations.
Dry powder is normally held at -20 °C or lower, away from light and moisture. Sealed vials can also be kept at 2-8 °C for shorter intervals. Warming to room temperature before opening prevents condensation.