melanocortin signalling is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2025-10-16. Numbers and descriptions here follow the published literature rather than marketing material.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It is described in the literature as an analogue of the ACTH(4–10) fragment, a short N-terminal portion of adrenocorticotropic hormone that retains some neurotropic activity without the full hormonal effects of the parent peptide. The molecule carries a methionine residue at the N-terminus and two proline residues near the C-terminus, features that shape both its interactions with receptor systems and its chemical stability. The free peptide corresponds to the formula C37H51N9O10S and a molecular mass near 813.9 Da.
The compound was developed in the 1980s at the Institute of Molecular Genetics in Moscow, where it emerged from research on short ACTH fragments and their effects on the central nervous system. Russian pharmaceutical listings describe it as a nootropic and neuroprotective agent, most often formulated as nasal drops. It is not a marketed medicine in the United States or the European Union, and no pharmacopoeial monograph covers it. Consequently, most published clinical experience with the substance originates from a small number of research centres, mainly in Russia and neighbouring countries.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Free acid form of the heptapeptide; depends on terminal groups |
| Molecular mass | About 813.9 g/mol | Average mass used for mass spectrometry confirmation |
| Appearance | White to off-white solid | Supplied as a lyophilised powder; hygroscopic |
| Solubility class | Freely soluble in aqueous media | Water, saline, and phosphate buffers; limited organic solubility |
| Typical storage temperature | -20 degrees Celsius | Long term and dry; short working periods may use 2 to 8 degrees Celsius |
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.
Identity and purity of semax are established with reversed-phase high-performance liquid chromatography coupled to ultraviolet detection, usually at 214 nanometres. Mass spectrometry, most often electrospray ionisation in positive mode, confirms the molecular mass and reveals truncated sequences. Amino acid analysis and peptide mapping after enzymatic digestion provide additional structural confirmation. Laboratories typically report purity as the percentage area of the main peak, a figure that does not capture isomeric or oxidised variants unless the method resolves them.
The peptide is prone to several degradation pathways. Oxidation of the methionine residue produces a sulfoxide that elutes close to the parent peak in many chromatographic systems. Hydrolysis of peptide bonds and deamidation of susceptible residues in related sequences also reduce purity over time. Lyophilised material kept dry at minus twenty degrees Celsius and shielded from light is the most stable form commonly described in laboratory practice.
=== Tolerance === A very rapid and strong tolerance, known as tachyphylaxis, develops to the effects of psychedelics with repeated administration. It develops with a single dose and is present within hours to days. Already by the second day, with LSD, there was a 50% decrease in psychoactive effects in one study. Following a few days of repeated administration, or 3 to 4 days in the case of LSD, there is an almost complete absence of effects. The tolerance remains stable thereafter. In one study that gave LSD continuously for up to 84 days, doubling, tripling, and quadrupling the dose was unable to fully overcome the tolerance and restore effects. An abstinence period of 3 to 6 days is required for sensitivity to return and tolerance to fully reset. LSD, psilocybin, and mescaline all show cross-tolerance with each other. Tolerance has been shown to develop to numerous psychedelics in animals and/or humans. Tolerance with psychedelics develops to both their psychoactive effects and their physical effects, such as pupil dilation and tachycardia. As a result of the tolerance, recreational psychedelic users do not use the drugs daily but often show a once-per-week use pattern. Some possible exceptions among psychedelics which may not build tolerance or may develop it much less rapidly include dimethyltryptamine (DMT), ayahuasca (which contains DMT), and 5-MeO-DMT. Similarly, the structurally related dipropyltryptamine (DPT) and diisopropyltryptamine (DiPT) did not show behavioral tolerance in rodents, in contrast to DOI and 2C-T-7.
Play Australian rules football at any level; Enter the club premises or clubrooms on game day; Train under the direction of a club-devised program; or Return to their clubs' training sessions until two months before their bans expired. Because of these limitations, the bans also covered most forms of coaching. As such, two former players (Mark McVeigh and Henry Slattery) who were employed as non-playing coaches were suspended from their jobs, and players serving as playing coaches in country leagues were suspended from performing either function. The bans extended to any sport administered by a signatory to the WADA code, precluding active involvement in almost any organised sport during 2016. Players were not completely banned from involvement with the AFL, and were permitted to:
For just as a man has a body that is no different in principle from that of an animal, so also his psychology has a whole series of lower storeys in which the spectres from humanity's past epochs still dwell, then the animal souls from the age of Pithecanthropus and the hominids, then the "psyche" of the cold-blooded saurian. Jung's notion of different evolutionary layers in the human mind has been compared with the work of neuroscientist Jaak Panksepp, particularly as outlined in his book The Archaeology of Mind: Neuroevolutionary Origins of Human Emotions. Of these affinities it has been suggested that 'Jung and Panksepp have, independently it seems, developed similar metaphors of an archeologically layered psyche in which jewels and treasures are discoverable in the deepest phylogenetically ancient regions of the brain – for Jung they are archetypal structures for Panksepp cross-species homologies.' Significantly, in a 2017 article entitled "The Affective Core of the Self: A Neuro-Archetypical Perspective on the Foundations of Human (and Animal) Subjectivity", when noting Jung's belief that archetypes may be related to evolutionarily ancient subcortical brain systems, Panksepp and colleagues wrote that "such assertions by Jung were not only quite farsighted, but they actually open ways to connect his theory of the psyche with the most advanced scientific theories and discoveries of our day."
Sources: en.wikipedia.org
== Function == The pancreas is involved in blood sugar control and metabolism within the body and also in the secretion of substances (collectively pancreatic juice) that help digestion. These functions are divided into an endocrine role, relating to the secretion of insulin and other hormones within pancreatic islets that help control blood sugar levels and metabolism, and an exocrine role, relating to the secretion of pancreatic digestive enzymes.
== Reception == Spin wrote, "Poised to become this year's Scorpions, the band (like so many other freeze-dried HM acts) looks more like Spinal Tap. Metal Heart reeks of studied moves. The squalling guitars and lockstep beat on Metal Heart are characteristic Eurometal trademarks. Accept is just another commodity."
Mérimée illustrated these color relationships with a simple diagram located between pages 244 and 245: Chromatic Scale (Echelle Chromatique).De la peinture à l’huile : ou, Des procédés matériels employés dans ce genre de peinture, depuis Hubert et Jean Van-Eyck jusqu’à nos jours was published in 1830 and an English translation by W. B. Sarsfield Taylor was published in London in 1839. Similar ideas about the creation of color using red, yellow, and blue were discussed in Theory of Colours (1810) by the German poet, color theorist and government minister Johann Wolfgang von Goethe. In The Law of Simultaneous Color Contrast (1839) by the French industrial chemist Michel Eugène Chevreul discussed the creation of numerous color nuances and his color theories were underpinned by the RYB color model. Separate to the RYB color model, cyan, magenta, and yellow primary colors are associated with CMYK commonly used in the printing industry. Cyan, magenta, and yellow are often referred to as "process blue", "process red", and "process yellow".
Sources: en.wikipedia.org
It is described as a synthetic analogue of the ACTH(4–10) fragment, a short segment of adrenocorticotropic hormone. Its sequence differs from that fragment and includes two proline residues, which influence stability and behaviour in solution.
It appears in Russian pharmaceutical listings as a nasal formulation, but it is not an authorised medicine in the United States or the European Union. Outside those markets it is normally encountered as a research chemical rather than a prescription product.
Laboratory and animal work points to melanocortin signalling and changes in neurotrophic factor levels, especially brain-derived neurotrophic factor. The exact receptor targets and the degree to which these findings transfer to humans are 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.