This is a working overview of tetrapeptide, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-07-04. Anything still debated is marked as such rather than presented as settled.
Regulatory treatment differs by country. No formulation of epitalon holds a marketing authorisation as a medicine in the United States or the European Union, where material sold for laboratory use is handled as a research chemical and is not intended for human consumption. In Russia, several short peptide preparations from the same institute's peptide series are registered medicinal products, and epitalon appears in that national context. Elsewhere it is frequently offered as a cosmetic ingredient, a category with lighter requirements. Advertising claims about longevity or disease prevention are restricted in most jurisdictions, which limits how sellers describe the compound.
Freeze-dried epitalon is normally kept at minus twenty degrees Celsius in a sealed, desiccated container, protected from light. Short excursions at ambient temperature during shipping are generally tolerated, but repeated warming and cooling cycles encourage moisture uptake, which shortens shelf life. Once dissolved, the peptide is far less stable than the solid: aqueous solutions are subject to hydrolysis and to deamidation at the aspartate and glutamate residues. Working solutions are therefore held refrigerated and used within days, and repeated freezing and thawing of the same vial is best avoided.
Storage recommendations center on limiting moisture, heat, and light. The dry powder is generally kept at minus 20 degrees Celsius, and some suppliers recommend minus 80 degrees for long-term archival. Once dissolved, solutions are usually aliquoted and frozen to avoid repeated freeze-thaw cycles, which can promote aggregation or degradation. Aqueous stability depends on pH and concentration, and buffered saline is often preferred over plain water for biological work. Stability data specific to epitalon remain limited, so general peptide-handling practices are applied by analogy rather than from product-specific validation.
Epitalon is a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, abbreviated AEDG. Its molecular formula is C14H22N4O9 and its calculated monoisotopic mass is approximately 390.35 daltons. The compound does not occur naturally as a free peptide; it is produced by solid-phase peptide synthesis. Because it contains two acidic residues and no basic residues, the neutral form carries a net negative charge at physiological pH. This charge profile influences how the peptide behaves in solution and during chromatographic analysis.
| Property | Value | Notes |
|---|---|---|
| Storage temperature, solid | Approximately -20 C | Sealed, desiccated, protected from light |
| Typical identity method | Electrospray mass spectrometry | Protonated ion expected near 391 |
| Typical purity method | Reversed-phase HPLC | Ultraviolet detection near 214 nm |
| Common synonyms | Epithalon, epithalone, AEDG | Spelling variants appear in supplier catalogues |
| Solution stability | Days at 2-8 C | Hydrolysis and deamidation limit shelf life |
Human data are limited to small studies, often without the randomization, blinding, or control groups expected in contemporary clinical research. Reported outcomes have included changes in melatonin levels, immune markers, and subjective measures, but sample sizes were generally too small to support firm conclusions. Some reviews treat the peptide as promising while noting methodological weaknesses; others question whether the observed effects are specific. The compound is frequently discussed in longevity-focused communities, where enthusiasm often outpaces the published evidence. Separating established findings from speculation is therefore important when reading summaries of this research.
Epitalon emerged from research conducted in Saint Petersburg by Vladimir Khavinson and colleagues, who studied short peptides as potential regulators of aging. The work built on epithalamin, a pineal gland extract reported to influence neuroendocrine function. Epitalon was designed as a synthetic counterpart with a defined sequence, allowing reproducible experiments that extracts could not support. Early publications described effects on melatonin rhythms and lifespan in animal models. These findings circulated mainly in Russian-language journals during the 1990s, which limited their visibility among English-speaking researchers.
The most widely cited claim is that epitalon activates telomerase and thereby extends telomere length. Supporting evidence comes largely from cultured human cells, where treatment was associated with increased telomerase activity and delayed replicative senescence. Telomerase activation is a biologically consequential effect, since the enzyme is largely silenced in most somatic cells. However, the route by which a short peptide would reach and act on the enzyme's regulatory machinery has not been established. Independent replication in human trials is scarce, so the link between cell-culture observations and whole-body aging remains an open question.
The peptide is a synthetic analogue of epithalamin, a preparation extracted from bovine pineal glands. Investigators sought a short, chemically defined molecule that would reproduce some of the endocrine and gerontological observations attributed to the glandular extract. Proposed mechanisms centre on induction of telomerase activity, an effect reported in cultured human somatic cells in the early 2000s, together with influences on melatonin secretion and neuroendocrine regulation. Those mechanisms remain incompletely characterised, and the reported telomerase response has not been consistently reproduced by independent groups working in comparable systems.
Published work on this compound consists mainly of in vitro experiments, animal studies, and small clinical investigations, a substantial share of which appeared in Russian-language journals. Sample sizes are generally small, control conditions differ between studies, and several endpoints rely on markers whose clinical meaning is itself debated. Reviews of the longevity field treat the peptide as an early example of telomerase-directed research rather than an established intervention. Regulatory treatment varies by country: some jurisdictions place it under prescription controls, others treat it as a laboratory material, and importation may be restricted regardless of local status.
Epitalon is a synthetic tetrapeptide whose sequence is alanine–glutamate–aspartate–glycine, commonly abbreviated AEDG. It was developed in Russia during the 1980s and 1990s by investigators associated with the St. Petersburg Institute of Bioregulation and Gerontology, who studied short peptides as regulators of gene expression and tissue function. The alternative spelling epithalon appears interchangeably in the literature, and the two names refer to the same molecule. Outside Russia it is encountered chiefly as a research chemical rather than a licensed medicine, and it holds no approval from the United States Food and Drug Administration or the European Medicines Agency.
No pharmacopoeial monograph exists for this peptide, so quality rests on the supplier's internal specifications and on whatever independent testing a purchaser arranges. Certificates of analysis differ widely in which tests they report and in the limits applied. The counter-ion introduced during purification, commonly acetate or trifluoroacetate, changes the net peptide content of a given mass of powder, so two samples of equal weight may not contain equal amounts of the active sequence. Third-party laboratories can verify purity, identity, residual solvents, and counter-ion content for a fee, which makes documentation more informative than labelling.
Verification of a sample usually begins with reversed-phase high-performance liquid chromatography, which resolves the peptide from truncated sequences and other impurities and expresses purity as a percentage of total peak area. Mass spectrometry by electrospray ionisation or matrix-assisted laser desorption supplies an independent check, because the measured mass can be compared against the theoretical value for AEDG. Amino acid analysis or tandem mass spectrometry sequencing can confirm residue order. Each of these methods answers a different question: a purity figure does not establish identity, and an identity match does not establish how much of the material is intact peptide.
Epitalon is a synthetic tetrapeptide with the residue sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. Its monoisotopic mass is approximately 390.35 daltons, and it is usually supplied as a lyophilised trifluoroacetate or acetate salt. The compound was derived from a pineal gland extract called epithalamin, a heterogeneous preparation investigated in the former Soviet Union. Researchers associated with the Saint Petersburg Institute of Bioregulation and Gerontology described the tetrapeptide as a constituent fragment of that extract. Commercial material is offered as a laboratory reagent rather than as a finished pharmaceutical product.
Literature searches for this compound must account for several spelling variants. Indexing databases contain epitalon, epithalon, epithalone, and AEDG, and relevant records are scattered across Russian-language and English-language journals that do not consistently cross-cite. Early publications describe the parent extract as a mixture of many peptides, whereas later work addresses the single synthetic tetrapeptide. That shift in nomenclature complicates comparison between studies, because extract data and tetrapeptide data are sometimes cited interchangeably. A search strategy omitting the alternate spellings will return an incomplete set of references.
Furthermore, a study examining 20 different human tumors uncovered a recurrent mutation in ANKRD26 that adversely affects the interaction between ANKRD26 and PIDD1 with centrosomes, thereby increasing the survival of cells with more than required number of centrosomes. The process of centrosome accumulation initiates a signaling pathway characterized by the involvement of Caspase-2 and the PIDDosome, which collectively contribute to the stabilization of p53 and the induction of p21 expression. This series of events can lead to an increase in PIDD1 levels over time, as it is also a downstream target of p53. The observed rise in PIDD1 expression is likely a result of subsequent DNA damage occurring in cells that fail to effectively arrest their cell cycle in the presence of excess centrosomes. Consequently, this situation may activate p53 through either the conventional DNA damage response mechanism or as a result of delayed M-phase progression caused by complications in chromosome alignment. This mechanism guarantees the effective operation of the p21 checkpoint, which, in turn, promotes the viability of aneuploid cells. At the same time, a lack of CASP2 intensifies tumor advancement in this cancer model following treatment with cisplatin, leading to an accelerated progression of the malignancy. PIDDosome-deficient animals provide an intriguing model for exploring the effects of ploidy on liver function and regenerative processes, avoiding the complications that arise from a global deficiency of p53.
== Education and early career == Cremer's father moved to a new position in Berlin and Cremer had trouble adjusting to the new Prussian school system. Cremer graduated high school in Berlin in 1921 and matriculated to the University of Berlin to study chemistry. At the University of Berlin, she attended lectures by Fritz Haber, Walther Nernst, Max Planck, Max von Laue, and Albert Einstein. Cremer received her Ph.D. magna cum laude six years later in 1927 under Max Bodenstein. Her dissertation was on the kinetics of the hydrogen-chlorine reaction. The paper was published under her name only because it concluded that the hydrogen-chlorine reaction was a chain reaction, which was still considered an extremely original concept for that time. Because of this paper and her work on kinetics, the future Nobel Laureate for the study of kinetics, Nikolay Semyonov invited her to Leningrad to work. She refused and remained in Germany to work at the Kaiser Wilhelm Institute for Physical Chemistry and Electrochemistry with Karl Friedrich Bonhoeffer on the quantum theoretical problems of photochemistry. Cremer studied the breakdown of alcohols using oxide catalysts on scholarship at the University of Freiburg with George de Hevesy for a brief time. Cremer returned to Berlin to work with Michael Polanyi at Haber's Institut, where they investigated the conversion of hydrogen and ortho-hydrogen in one spin state to para-hydrogen. She remained there until 1933 when the Nazi party came to power in Germany and the institute was dissolved for its reputation as anti-Nazi.
Education in spiritual and religious matters is also required by the American Psychiatric Association, however, far less attention is paid to the damage that more rigid, fundamentalist faiths commonly practiced in the United States can cause. This theme has been widely politicized in 2018 such as with the creation of the Religious Liberty Task Force in July of that year. Also, many providers and practitioners in the United States are only beginning to realize that the institution of mental healthcare lacks knowledge and competence of many non-Western cultures, leaving providers in the United States ill-equipped to treat patients from different cultures.
In the pharmaceutical industry, a blockbuster drug is one that achieves acceptance by prescribing physicians as a therapeutic standard for, most commonly, a highly prevalent chronic (rather than acute) condition. Patients often take the medicines for long periods.
=== Mass spectrometry === Deuterated (i.e. where all or some hydrogen atoms are replaced with deuterium) compounds are often used as internal standards in mass spectrometry. Like other isotopically labeled species, such standards improve accuracy, while often at a much lower cost than other isotopically labeled standards. Deuterated molecules are usually prepared via hydrogen isotope exchange reactions.
Sources: en.wikipedia.org
=== Argentina === In 2011, Argentina introduced a catalogue of drugs covered by its national drug traceability scheme, listing more than 3,000 drugs that require the placing of unique serial numbers and tamper-evident features on the secondary packaging. The drugs listed are recorded in real time in a central database managed by the National Administration of Drugs, Foods, Medical Devices of Argentina (ANMAT), Regulation 3683, which uses Global Location Numbers (GLNs) to identify the various actors in the supply chain. The purpose of this program is to actively limit the use of illegal drugs.
=== Lightweight === Backpackers must carry everything with them so they require all of their gear and food to be as lightweight as possible. Campers often turn to freeze-dried and dehydrated meals and ingredients for this reason, but they will also sometimes take a pouch of tuna or some other ingredient with a high water content with them as a treat, providing that the item has nutritional value. Backpackers usually take empty containers back with them for recycling and proper disposal.
Tulips are mainly distributed along a band corresponding to latitude 40° north, from southeast of Europe (Greece, Albania, North Macedonia, Kosovo, Southern Serbia, Bulgaria, most part of Romania, Ukraine, Russia) and Turkey in the west, through the Levant (Syria, Israel, Palestinian Territories, Lebanon and Jordan) and the Sinai Peninsula. From there it extends eastwards through Jerevan (Armenia), and Baku (Azerbaijan) and on the eastern shore of the Caspian Sea through Turkmenistan, Bukhara, Samarkand and Tashkent (Uzbekistan), to the eastern end of the range in the Pamir-Alai and Tien-Shan mountains in Central Asia, which form the centre of diversity. Further to the east, Tulipa is found in the western Himalayas, southern Siberia, Inner Mongolia, and as far as the northwest of China. While authorities have stated that no tulips west of the Balkans are native, subsequent identification of Tulipa sylvestris subsp. australis as a native of the Iberian Peninsula and adjacent North Africa shows that this may be a simplification. In addition to these regions in the west tulips have been identified in Greece, Cyprus and the Balkans. In the south, Iran marks its furthest extent, while the northern limit is Ukraine. Although tulips are also found throughout most of the Mediterranean and Europe, these regions do not form part of the natural distribution. Tulips were brought to Europe by travellers and merchants from Anatolia and Central Asia for cultivation, from where they escaped and naturalised (see map).
==== Drugs ==== Drug interaction: According to several studies in animals, oxytocin inhibits the development of tolerance to various addictive drugs (opiates, cocaine, alcohol), and reduces withdrawal symptoms. MDMA (ecstasy) may increase feelings of love, empathy, and connection to others by stimulating oxytocin activity primarily via activation of serotonin 5-HT1A receptors, if initial studies in animals apply to humans. The anxiolytic drug buspirone may produce some of its effects via 5-HT1A receptor-induced oxytocin stimulation as well. Addiction vulnerability: Concentrations of endogenous oxytocin can impact the effects of various drugs and one's susceptibility to substance use disorders, with higher concentrations associated with lower susceptibility. The status of the endogenous oxytocin system can enhance or reduce susceptibility to addiction through its bidirectional interaction with numerous systems, including the dopamine system, the hypothalamic–pituitary–adrenal axis, and the immune system. Individual differences in the endogenous oxytocin system based on genetic predisposition, gender and environmental influences, may therefore affect addiction vulnerability. Oxytocin may be related to the place conditioning behaviors observed in habitual drug abusers.
In some jurisdictions, designer drugs may fall under analog acts which impose restrictions upon substances which are substantially chemically or pharmacologically similar to existing controlled substances.
Sources: en.wikipedia.org
=== Flavin-dependent ene-reductases === Flavin-dependent ERs perform their reactions using the cofactor flavin mononucleotide (FMN) that is non-covalently bonded to the enzyme and their catalytic mechanism is now well understood. In the natural cycle, the cofactor (FMN) is first reduced by NAD(P)H, then the reduced FMNH2 reduces the substrate by Michael-type hydride transfer to the β-carbon atom. In the end the protonation of the resulting anion occurs from the opposite face of the (C=C) bond through a tyrosine moiety or solvent. The overall reaction is an anti-trans-hydrogenation. This catalytic mechanism can also be regenerated from the natural nicotinamide cofactor with a substrate-coupled regeneration or the use of synthetic reductants and electrochemical or photochemical regeneration. The most predominant family of flavin-dependent ERs is the Old Yellow Enzyme (OYE) family of oxidoreductases (EC 1.6.99.1).The first OYE was discovered in baker's yeast (Saccharomyces cerevisiae) in 1933, and its name derives from the color it assumes when concentrated, which is due to the flavin cofactor. They catalyze the reduction of α,β-unsaturated compounds, with a high specificity for activating groups containing aldehydes, ketones, or nitro groups. Conversely, carboxylic acids and their derivatives such as esters and nitriles, are less activated and are considered as "borderline substrates".
2 NaN3 + 2 HNO2 → 3 N2 + 2 NO + 2 NaOH A safer modification to the above method that avoids the potential production of hydrazoic acid or nitrogen oxide fumes is that of W. F. Rinkenbach. A solution of 2.5 oz (71 g) sodium nitrite in 1 US pt (470 mL) of water is added to a stirring dispersion of 1 oz (28 g) sodium azide in 1.5 US gal (5.7 L) 10% ammonium acetate, followed by addition of 7 US fl oz (210 mL) of glacial acetic acid. The solution is allowed to stand in a warm place for an hour and disposed of.
Fermentation begins once the growth medium is inoculated with the organism of interest. Growth of the inoculum does not occur immediately. This is the period of adaptation, called the lag phase. Following the lag phase, the rate of growth of the organism steadily increases, for a certain period—this period is the log or exponential phase. After a phase of exponential growth, the rate of growth slows down, due to the continuously falling concentrations of nutrients and/or a continuously increasing (accumulating) concentrations of toxic substances. This phase, where the increase of the rate of growth is checked, is the deceleration phase. After the deceleration phase, growth ceases and the culture enters a stationary phase or a steady state. The biomass remains constant, except when certain accumulated chemicals in the culture chemically break down the cells in a process called chemolysis. Unless other microorganisms contaminate the culture, the chemical constitution remains unchanged. If all of the nutrients in the medium are consumed, or if the concentration of toxins is too great, the cells may become senescent and begin to die off. The total amount of biomass may not decrease, but the number of viable organisms will decrease.
A review of animal studies by the World Health Organization found no adverse health effects associated with dimethylpolysiloxane. TBHQ is a common preservative for vegetable oils, cereals, nuts, cookies, chips and animal fats, found in other foods such as Girl Scout Cookies and Quaker Chewy Granola Bars. The U.S. Food and Drug Administration sets an upper limit of 0.02% of the oil or fat content in foods, which like other foods, applies to the oil used in McNuggets. Effective use of TBHQ was 1 gram per 5,000 grams of cooking oil (1 gram per 11.023 pounds of cooking oil).
Sources: en.wikipedia.org
The solid is kept cold, dry and dark, typically at minus twenty degrees Celsius, in a sealed container with desiccant. Dissolved material is kept refrigerated and used promptly. Freezing and thawing a solution repeatedly is avoided because it accelerates degradation.
Reversed-phase chromatography with ultraviolet detection gives a purity percentage, while mass spectrometry confirms identity. Amino acid analysis checks the residue composition. Buyers typically request a certificate of analysis showing these measurements for the specific lot.
It is not authorised as a medicine in the United States or the European Union. Material is sold there as a research chemical or cosmetic ingredient. Some related short peptides are registered drugs in Russia, which is a distinct national situation rather than a general approval.
Epitalon is a synthetic tetrapeptide built from four amino acids: alanine, glutamate, aspartate, and glycine. It is not extracted from a natural source but made in the laboratory by chemical synthesis. Its short length makes it relatively straightforward to produce at high purity.