If you have been reading about shelf life 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 2026-05-08. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
Semax is supplied as a lyophilized powder that appears white to off-white. It dissolves readily in water, phosphate-buffered saline, and other aqueous media, which simplifies preparation of working solutions for laboratory use. The nasal products registered in Russia are dilute aqueous solutions, typically around 0.1 percent peptide by weight. Organic solvents are rarely necessary and can complicate handling. Because the peptide is hygroscopic, weighing should be performed quickly and with minimal exposure to ambient humidity.
Solid material is normally kept at minus 20 degrees Celsius in a sealed, desiccated container. Reconstituted solutions are less stable and are usually divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are avoided because they promote aggregation and loss of activity. Light exposure is minimized by using amber glassware or foil wrapping. Published stability data for this peptide are sparse, so recommended storage conditions rest mainly on general practice for short synthetic peptides rather than on dedicated study.
| 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 |
The parent fragment ACTH(4-10) carries the sequence Met-Glu-His-Phe-Arg-Trp-Gly. Semax replaces the arginine and tryptophan positions with a proline-glycine-proline tail, giving Met-Glu-His-Phe-Pro-Gly-Pro. That change removes residues associated with adrenal stimulation, so the peptide does not drive cortisol release the way full ACTH does. This distinction shapes how the compound is grouped in the literature, where it sits with neuropeptides and peptide neuromodulators rather than with corticosteroids.
Regulatory status varies sharply by country. Semax is registered for medical use in Russia, where it appears in formularies as a nasal solution, and it also holds registration in a small number of neighbouring states. It has no approval from the United States Food and Drug Administration or the European Medicines Agency, and it is not a scheduled controlled substance in most jurisdictions. Elsewhere it circulates mainly as laboratory material, so purity documentation comes from suppliers rather than from a national pharmacopoeia.
Semax is a synthetic peptide created in the Soviet Union during the early 1980s by researchers working in Moscow. It was built from the short adrenocorticotropic hormone fragment known as ACTH(4-10), and the chain was then extended with three additional amino acids. The resulting molecule was named semax and entered clinical use in Russia in 1994. It is generally described as a nootropic and neuroprotective agent rather than as a hormone analogue.
Published research has focused mainly on neurological and cognitive endpoints in animal models, with proposed mechanisms involving brain-derived neurotrophic factor and related signalling pathways. A substantial share of the human data originates from a limited number of research groups, and independent replication in other countries remains sparse. Regulatory status reflects that distribution: the peptide is registered as a medicine in Russia and appears in some neighbouring markets, while elsewhere it is handled as a research chemical without approved therapeutic labelling. Questions about dose-response relationships, long-term effects, and comparability across studies are still open.
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.
=== Australia === In Australia, the Therapeutics Goods Administration (TGA) considers preparations to be bioequivalent if the 90% confidence intervals (90% CI) of the rate ratios, between the two preparations, of Cmax and AUC lie in the range 0.80–1.25. Tmax should also be similar between the products. There are tighter requirements for drugs with a narrow therapeutic index and/or saturable metabolism – thus no generic products exist on the Australian market for digoxin or phenytoin for instance.
=== Recombinant human CNTF (Axokine) === A recombinant version of human CNTF (rhCNTF), trade name Axokine, is a modified version with a 15 amino acid truncation of the C-terminus and two amino acid substitutions. It is three to five times more potent than CNTF in in vitro and in vivo assays and has improved stability properties. Like CNTF it is a neurotrophic factor, and may stimulate nerve cells to survive. It was tested in the 1990s as a treatment for amyotrophic lateral sclerosis. It did not improve muscle control as much as expected, but trial participants did report a loss of appetite. Phase III clinical trials for the drug against obesity were conducted in 2003 by Axokine's maker, Regeneron Pharmaceuticals, demonstrating a small positive effect in some patients, but the drug was not commercialized. A major problem with the treatment was that in nearly 70% of the subjects tested, antibodies against Axokine were produced after approximately three months of treatment. In the minority of subjects who did not develop the antibodies, weight loss averaged 12.5 pounds in one year, versus 4.5 pounds for placebo-treated subjects. In order to obtain this benefit, subjects needed to receive daily subcutaneous injections of one microgram Axokine per kilogram body weight. Xencor patent application raises the disturbing idea that subjects producing antibodies against CNTF analogues may eventually suffer severe adverse effects, as these antibodies could potentially interfere with the neuroprotective functions of endogenous CNTF.
This competition could alter the post-transcriptional gene regulation (PTGR) of ADME-related genes, leading to indirect modulation of the expression of drug-metabolizing enzymes or transporters and causing DDIs with co-administered drugs. Short hairpin RNAs (shRNAs) may additionally compete with pre-miRNAs for the nuclear export protein Exportin-5 (XPO5) and the cytoplasmic ribonuclease Dicer, disrupting global miRNA biogenesis and posing further DDI risk. The U.S. Food and Drug Administration has issued guidance specific to oligonucleotide therapeutics, recommending assessment of QTc interval prolongation, immunogenicity, organ-impairment effects on PD endpoints, and the potential for RNAi machinery competition as part of the DDI risk framework for this drug class.
== Location and characteristics == The location of prolactin cells within the pituitary gland is regulated largely by the hypothalamus. The pituitary gland is divided into posterior and anterior regions. Within the anterior pituitary gland are the prolactin cells, where they secrete the hormone prolactin. Prolactin cells vary in number, size, and appearance depending on female reproductive status. Prolactin cells specifically increase in response to the physiological state of pregnancy, in particular, the need for the development of breast tissues and milk production. During pregnancy, prolactin cells will undergo hypertrophy (enlarging to support increased prolactin production) as well as hyperplasia (an increase in cell number). The pituitary gland increases in size due to the amount of prolactin cells. The secretory granules of prolactin cells fluctuate from sparsely granulated (during periods of low prolactin production) to densely granulated (during periods of high prolactin production). Prolactin cells contain a large amount of rough endoplasmic reticulum, where prolactin synthesis occurs. The trans-Golgi layer is responsible for storing the prolactin hormone into secretory granules, which are dissolved upon secretion out of the cell. Lysosomal enzymes are involved in the degradation of the secretory granules. The prolactin hormone is a single polypeptide chain protein composed of 199 amino acids in humans. It consists of “three intramolecular disulfide bonds located between six cysteine residues (Cys4-Cys11, Cys58-Cys174, and Cys191-Cys199”.
The heightened vigilance of the German garrison as the war entered its final phase made these operations especially hazardous, particularly as they were often attempted at extremely close quarters. On several occasions Rhodesian patrols only narrowly escaped discovery. During one action, two Rhodesian patrols catered for the possibility that Germans might be listening to their transmissions by communicating in Shona, an African language. The LRDG's last actions of the war, in April and May 1945, were to help Tito's partisans capture German-held islands off Dalmatia.
Sources: en.wikipedia.org
=== Migraine === Methylergometrine is sometimes used for both prevention and acute treatment of migraine. It is an active metabolite of methysergide. In the treatment of cluster headaches, methylergometrine has been initiated at a dose of 0.2 mg/day, rapidly increased to 0.2 mg three times per day, and increased to a maximum of 0.4 mg three times per day.
Becker muscular dystrophy has adult-onset exercise-induced muscle cramping, pain, and elevated CK. Tubular aggregate myopathy (TAM) types 1 and 2 has exercise-induced muscle pain, fatigue, stiffness, with proximal muscle weakness and calf muscle pseudohypertrophy. TAM1 has cramping at rest, while TAM2 has cramping during exercise. Stormorken syndrome includes the symptoms of TAM, but is a more severe presentation including short stature and other abnormalities. Satoyoshi syndrome has exercise-induced painful muscle cramps, muscle hypertrophy, and short stature. Dimethylglycine dehydrogenase deficiency has muscle fatigue, elevated CK, and fishy body odour. Myopathy with myalgia, increased serum creatine kinase, with or without episodic rhabdomyolysis (MMCKR) has exercise-induced muscle cramps, pain, and fatigue; with some exhibiting proximal muscle weakness.
This has reduced the risk of occupationally induced cancer from radon, although health issues may persist for those who are currently employed in affected mines and for those who have been employed in them in the past. As the relative risk for miners has decreased, so has the ability to detect excess risks among that population.
Shorter HRTs support the development of non-exoelectrogenous bacteria which can reduce the Coulombic efficiency electrochemical performance of the fuel cell if the anodophiles must compete for resources or if they do not have ample time to effectively degrade nutrients.
Sources: en.wikipedia.org
== Further reading == Laurence, J (2015). "Centennial celebration of Translational Research: The Journal of Laboratory and Clinical Medicine". Translational Research. 165 (1): 1–6. doi:10.1016/j.trsl.2014.08.004. PMID 25301250. Hammerschmidt, DE (2004). "A new look and a heightened focus: Translational medicine and the Journal of Laboratory and Clinical Medicine". Journal of Laboratory and Clinical Medicine. 144 (1): 5–6. doi:10.1016/j.lab.2004.05.006. Vaughan, WT (1940). "We celebrate our silver anniversary". Journal of Laboratory and Clinical Medicine. 26 (1): 1–3.
Noroxycodone is the major metabolite of the opioid analgesic oxycodone. It is formed from oxycodone in the liver via N-demethylation predominantly by CYP3A4. Noroxycodone binds to and activates the μ-opioid receptor (MOR) similarly to oxycodone, although with one-third of the affinity of oxycodone and 5- to 10-fold lower activational potency. However, although a potent MOR agonist, noroxycodone poorly crosses the blood-brain-barrier into the central nervous system, and for this reason, is only minimally analgesic in comparison.
In 1820, Michael Faraday liquefied ammonia and other gases by using high pressures and low temperatures, and in 1834, Jacob Perkins built the first working vapor-compression refrigeration system in the world. It was a closed-cycle that could operate continuously, as he described in his patent, "I am enabled to use volatile fluids for the purpose of producing the cooling or freezing of fluids, and yet at the same time constantly condensing such volatile fluids, and bringing them again into operation without waste." His prototype system worked although it did not succeed commercially. In 1842, a similar attempt was made by physician John Gorrie, who built a working prototype, but it was a commercial failure. Like many of the medical experts during this time, Gorrie thought too much exposure to tropical heat led to mental and physical degeneration, as well as the spread of diseases such as malaria. He conceived the idea of using his refrigeration system to cool the air for comfort in homes and hospitals to prevent disease. American engineer Alexander Twining took out a British patent in 1850 for a vapour compression system that used ether. The first practical vapour-compression refrigeration system was built by the journalist James Harrison. His 1856 patent was for a vapour-compression system using ether, alcohol, or ammonia. He built a mechanical ice-making machine in 1851 on the banks of the Barwon River at Rocky Point in Geelong, Victoria, and his first commercial ice-making machine followed in 1854.
The Korean War, which began in 1950, was a shock to the US military and highlighted the deficiencies in psychological warfare. In spite of this, United Nations Partisan Forces Korea operated on islands and behind enemy lines. These forces were also known as the 8086th Army Unit, and later as the Far East Command Liaison Detachment, Korea, FECLD-K 8240th Army Unit. These troops directed North Korean partisans in raids, harassment of supply lines, and the rescue of downed pilots. Experience gained in the Korean War by these units influenced the development of U.S. Army Special Forces doctrine. Special Forces were formed in 1952, initially under the U.S. Army Psychological Warfare Division headed by then Brigadier General Robert A. McClure, due to the identified need to have psychological warfare capabilities. McClure specialized in psychological warfare but had little experience in unconventional warfare, though he believed the two were inextricably linked. Special Operations Command was formed by the U.S. Army Psychological Warfare Center which was activated in May 1952. The initial 10th Special Forces Group was formed in June 1952 and was commanded by Colonel Aaron Bank who is known as the father of Special Forces. The first Executive Officer was LTC William C. Martin, Jr. The 10th SFG's formation coincided with the establishment of the Psychological Warfare School, which is now known as the John F. Kennedy Special Warfare Center and School.
==== Gender and sex bias ==== In 2014, it was announced that the NIH is directing scientists to perform their experiments with both female and male animals, or cells derived from females as well as males if they are studying cell cultures, and that the NIH would take the balance of each study design into consideration when awarding grants. The announcement also stated that this rule would probably not apply when studying sex-specific diseases (for example, ovarian or testicular cancer).
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.
Solid peptide is best kept frozen at about minus 20 degrees Celsius in a sealed container with desiccant. It should be allowed to reach room temperature before opening to prevent condensation. Repeated warming and cooling of the same vial is discouraged.