If you have been reading about intranasal delivery 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.
Updated 2025-10-21. Numbers and descriptions here follow the published literature rather than marketing material.
Published studies examine a fairly narrow set of endpoints. Rodent experiments commonly measure maze learning, infarct volume after induced ischemia, and tissue levels of neurotrophic factors. Clinical reports from Russian centres describe attention, memory and recovery scores in patients after stroke or transient ischemic attack. Most of those human studies are small and few have been repeated by independent groups. Outcome measures differ between studies, which limits direct comparison.
Circulation time for the peptide is short because peptidases cleave it readily. The Pro-Gly-Pro tail is thought to slow breakdown compared with the bare ACTH fragment, but the gain appears modest. Absorption after intranasal dosing is limited, and only a fraction of a dose is expected to reach the central nervous system. Laboratory concentrations therefore sit well above levels achieved systemically, a gap that complicates translation from bench findings to clinical claims.
The mechanisms attributed to semax are inferred from animal and cell studies rather than traced to one confirmed target. The most frequently cited pathway involves increased expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal and cortical tissue. Some work points to engagement of melanocortin receptors, particularly MC4, which the parent ACTH fragment can activate. Effects on dopaminergic and serotonergic signalling have also been reported. No single account explains all observed results, and the relative weight of each pathway remains unsettled.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilized solid from research suppliers |
| Solubility | Freely soluble in water | Also dissolves in aqueous buffers; solutions are used fresh |
| Typical storage temperature | -20 °C for lyophilized powder | Short-term transport at 2-8 °C is common |
| Common analytical method | Reverse-phase HPLC | Paired with mass spectrometry for identity confirmation |
| Common synonyms | ACTH(4-10) analogue; MEHFPGP | N-terminal methionine retained in the chain |
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.
== Clinical features == The disease caused by infection with this parasite is known as rangeliosis. In Brazil it is also known as nambi-uvú (bleeding ears), peste de sangue (bleeding plague) and febre amarela dos cães (yellow fever of dogs).
Edward Frank Gale. For political service. Richard Gallagher. For services to the community in Aberdeen. Lucy Gannon, Writer. For services to Television Drama. Richard Ian Gardner. For services to the Police. Arthur Buchan Geddes, Sector Officer, the Coastguard Agency, Department of Transport. Arthur Samuel George, School Crossing Patrol, Portsmouth, Hampshire. For services to Road Safety. James Alexander George, Administrative Officer, Ministry of Defence. Graham James Gibb, Leader, Grampian Police and Braemar Mountain Rescue Teams. For services to Mountain Rescue. Alison Gray Gibson, Temporary Project Manager, Royal Mail, Edinburgh. For services to the Post Office. Sydney Gibson, Secretary, Fergusons Lane Tenants Association. For services to the community in Scotswood, Newcastle-upon-Tyne. Valerie Gibson. For services to the Right to Peace and Quiet Campaign. Joan Giddings, lately Office Administrator, British Apparel and Textile Confederation. For services to the Clothing Industry. Elizabeth Glasgow. For services to the community in Wester Hailes, Edinburgh. John Glover. For services to Golf. Maureen Audrey Gobbett, Higher Executive Officer, Ministry of Defence. Major Douglas George Goddard. For services to the community in Wargrave-on-Thames, Berkshire. David William Goodall. For services to Nature Conservation in Hampshire. Ian Kenmure Evans-Gordon. For political service. Stephen Goulding, Pay Band 8, the Employment Service, Department for Education and Employment. Anne Greaves. For services to the Health and Safety Commission's Occupational Health Advisory Committee.
== Examples == Numerous endogenous compounds – including hormones, catecholamines such as dopamine and noradrenaline, and many trace amines (e.g. adrenaline, phenethylamine itself, tyramine, thyronamine, and iodothyronamine) – are substituted phenethylamines. Several notable recreational drugs, such as MDPV (Monkey Dust), MDMA (ecstasy), mescaline, methamphetamine, and cathinone, are also members of the class. Many well-known prescription drugs are from the phenylethylamine class such as Adderall which uses Amphetamine, Desoxyn which uses methamphetamine, and Sudafed which uses pseudoephedrine.
Sources: en.wikipedia.org
Providing a sense of scale, a forest 62,000 square kilometres (24,000 sq mi) in area, the size of the U.S. state of Pennsylvania, is estimated to emit 3.4 million kg (7.5 million lb) of terpenes on a typical August day during the growing season. Maize produces the VOC (Z)-3-hexen-1-ol and other plant hormones. The taste of bitterness, found in foods such as olives, coffee and dark chocolate is caused by detection of VOCs by taste receptors.
Casamino acid is the mixture of amino acids produced from acid hydrolysis of casein, a family of phosphoproteins found in mammalian milk. In comparison, tryptone describes casein that has undergone enzymatic degradation by the protease trypsin, leaving many smaller peptide chains alongside the free amino acids. Casamino acid is used as a component of microbiological growth medium to support protein synthesis. However, tryptophan, an essential amino acid, is lost while digesting the casein with strong acids. Providing this abundant source of nitrogen can alter the phenotype of microorganisms, such as bacterial species recognizing nutrient-rich media and reducing their motility, as compared to their typical environmental behaviors.
Cyanobacteria, the only prokaryotes performing oxygenic photosynthesis and the only prokaryotes that contain two types of photosystems (type I (RCI), also known as Fe-S type, and type II (RCII), also known as quinone type). The seven remaining prokaryotes have anoxygenic photosynthesis and use versions of either type I or type II. Chlorobi (green sulfur bacteria) Type I Heliobacteria Type I Chloracidobacterium Type I Proteobacteria (purple sulfur bacteria and purple non-sulfur bacteria) Type II (see: Purple bacteria) Chloroflexota (green non-sulfur bacteria) Type II Gemmatimonadota Type II Eremiobacterota Type II
The old "Same Olds" nickname fell into disuse, and by 1922 the other nicknames "Sash Wearers" and "Essendonians" that had been variously used from time to time were also abandoned. The team became universally known as "the Dons" (from EssenDON). (The club adopted the nickname "the Bombers" at the start of 1940 during the early phases of World War II, due to Windy Hill's proximity to what was then Melbourne’s main airport, Essendon Aerodrome.) In the 1922 season, playing in Essendon for the first time in decades, Essendon reached the final four for the first time since 1912, finishing in third place. In the 1923 season, the club topped the ladder with 13 wins from 16 games. After a 17-point Second Semi-Final loss to South Melbourne, Essendon defeated Fitzroy (who had beaten South Melbourne) in the 1923 Grand Final (then known as a "Challenge Final" due to its different finals format): Essendon 8.15 (63) to Fitzroy 6.10 (46). Amongst Essendon's best players were half-forward flanker George "Tich" Shorten, centre half-forward Justin McCarthy, centre half-back Tom Fitzmaurice, rover Frank Maher, and wingman Jack Garden. This was one of Essendon's most famous sides, dubbed the "Mosquito Fleet" due to the number of small, very fast players in the side. Six players were 5'6" (167 cm) or shorter.
Sources: en.wikipedia.org
It consists mainly of animal experiments and small clinical reports, with much of the clinical material published in Russian-language journals. Large independent trials are scarce. Separating reliable effects from chance findings is consequently difficult.
A fraction of an intranasal dose is thought to reach the central nervous system, and this route is favoured partly for that reason. The proportion is not well characterized. Direct measurement in humans remains difficult with current methods.
Raised BDNF and NGF expression has been reported across several animal studies, which makes the signal fairly consistent. Whether the same change occurs in humans at usable doses is not established. It is best treated as a working hypothesis rather than a confirmed clinical mechanism.
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.