The short version of AEDG peptide fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-09-10. Anything still debated is marked as such rather than presented as settled.
Storage and handling follow conventional peptide practice. Lyophilized epitalon is typically kept refrigerated or frozen, protected from moisture and light, and allowed to equilibrate to room temperature before opening to avoid condensation. Once dissolved, aqueous solutions are usually stored cold and used within a short period, since dilute peptide solutions can support microbial growth and may slowly degrade. The absence of cysteine and methionine reduces, but does not eliminate, oxidation concerns during long-term storage.
Regulatory status varies by country and is not harmonized. Epitalon is not an approved drug in major Western jurisdictions. In some countries it is sold as a research chemical, and in others it has appeared in products marketed for other categories. This inconsistent status means that purity, labeling accuracy, and documentation differ widely between suppliers, and verification of identity and purity through independent analysis is the usual way buyers assess a given lot.
The most frequently cited proposed action is induction of telomerase, the enzyme that adds repeat sequences to chromosome ends. Cell-culture work from the originating group reported higher telomerase reverse transcriptase expression and measurable telomere elongation in human somatic cells after exposure. How a four-residue peptide would reach nuclear gene regulation is not established, and no cell-surface receptor or uptake route has been identified. Additional reports describe changes in melatonin secretion, antioxidant enzyme activity and lipid peroxidation in aged animals, but these findings remain mechanistically unconnected to the telomerase observation.
Published evidence comes mainly from Russian-language journals and from a single research group, with small sample sizes and limited independent replication. A few laboratories outside that group have examined related peptides and reported weaker or absent telomerase effects, so the central claim is best described as contested rather than settled. Rodent studies report modest changes in some ageing markers and in survival, but designs vary and control conditions are often sparse. No large randomised trial in humans has been published, and long-term safety data in healthy populations are correspondingly thin.
Epitalon is a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. It was designed at the St. Petersburg Institute of Bioregulation and Gerontology as a short, chemically defined analogue of epithalamin, a fraction obtained from bovine pineal tissue. Small peptide bioregulators of this type formed a long-running line of work there from the 1980s onward. Because the molecule is produced by solid-phase synthesis rather than extraction, its composition is exact and its purity can be measured directly.
| Property | Value | Notes |
|---|---|---|
| Purity assessment | RP-HPLC | Reported as percent area, often ≥95% |
| Identity confirmation | Mass spectrometry | Observed mass compared with ~390 Da |
| Typical storage temperature | -20 °C or below | Lyophilized powder, desiccated |
| Reconstitution solvent | Sterile water or buffer | Acidic residues aid dissolution |
| Common synonyms | AEDG; epithalon | Spelling varies in literature |
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 parent extract epithalamin was characterised as a low-molecular-weight fraction of pineal tissue rather than a single defined chemical entity. Researchers fractionated it and tested successive fragments for activity, a screening approach typical of peptide discovery work in that era. Epitalon emerged from that process as one of the shorter sequences of interest. Because the original extract was never fully resolved into individual components, claims about which constituent drives a given effect rest on inference. This distinction matters when reading older reports that attribute extract observations to the tetrapeptide itself.
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.
Material sold for research use varies widely in documented quality. A useful verification package includes a certificate of analysis that states peptide content rather than only net weight, the chromatographic method and column used, and a mass spectrum consistent with the expected mass. Independent testing by a third-party laboratory is occasionally reported. Statements of identity resting only on a supplier label provide little assurance, and the gap between nominal mass and actual peptide content can be substantial once counterions and residual water are counted.
Peptides of this size are generally stable as dry solids but degrade in solution over time. The principal routes are hydrolysis of the peptide backbone and oxidation, with hydrolysis favoured by elevated temperature and extreme pH. Aqueous solutions held at room temperature can show measurable loss of purity within days, while frozen aliquots are considerably more durable. Because the sequence contains neither cysteine nor methionine, oxidation is less of a concern than for many other peptides, but pH control during handling still matters.
=== Social brain interconnectivity === A number of discrete brain regions and networks among regions that are involved in dealing with other people have been discussed together under the rubric of the social brain. As of 2012, there is a consensus that autism spectrum is likely related to problems with interconnectivity among these regions and networks, rather than problems with any specific region or network.
== Occurrence and nomenclature == The term nucleic acid is the overall name for DNA and RNA, members of a family of biopolymers, and is a type of polynucleotide. Nucleic acids were named for their initial discovery within the nucleus, and for the presence of phosphate groups (related to phosphoric acid). Although first discovered within the nucleus of eukaryotic cells, nucleic acids are now known to be found in all life forms including within bacteria, archaea, mitochondria, chloroplasts, and viruses (There is debate as to whether viruses are living or non-living). All living cells contain both DNA and RNA (except some cells such as mature red blood cells), while viruses contain either DNA or RNA, but usually not both. The basic component of biological nucleic acids is the nucleotide, each of which contains a pentose sugar (ribose or deoxyribose), a phosphate group, and a nucleobase. Nucleic acids are also generated within the laboratory, through the use of enzymes (DNA and RNA polymerases) and by solid-phase chemical synthesis.
== Function == PAPPA encodes a secreted metalloproteinase which cleaves insulin-like growth factor–binding proteins (IGFBPs). PAPPA's proteolytic function is activated upon collagen binding. It is thought to be involved in local proliferative processes such as wound healing and bone remodeling. Low plasma level of this protein has been suggested as a biochemical marker for pregnancies with aneuploid fetuses (fetuses with an abnormal number of chromosomes). For example, low PAPPA may be commonly seen in prenatal screening for Down syndrome. Low levels may alternatively predict issues with the placenta, resulting in adverse complications such as intrauterine growth restriction, preeclampsia, placental abruption, premature birth, or fetal death. This enzyme catalyses the following chemical reaction: Cleavage of the Met135-Lys bond in insulin-like growth factor binding protein (IGFBP)-4, and the Ser143-Lys bond in IGFBP-5 This enzyme belongs to the peptidase family M43.
== Principles == Proximity labeling relies on a labeling enzyme that can biotinylate nearby biomolecules promiscuously. Biotin labeling can be achieved through several different methods, depending on the species of labeling enzyme. BioID and TurboID rely on exogenous biotin supplementation; APEX and APEX2 utilize exogenous biotin phenol and hydrogen peroxide.
Sources: en.wikipedia.org
The redox reaction rate is limited by the formation of a favorable activated complex involving an oxo-bridge between the perchlorate anion and the metallic cation. It depends on the molecular orbital rearrangement (HOMO and LUMO orbitals) necessary for a fast oxygen atom transfer (OAT) and the associated electron transfer as studied experimentally by Henry Taube (1983 Nobel Prize in Chemistry) and theoretically by Rudolph A. Marcus (1992 Nobel Prize in Chemistry), both awarded for their respective works on the mechanisms of electron-transfer reactions with metal complexes and in chemical systems. In contrast to the Fe2+ cations which remain unoxidized in deaerated perchlorate aqueous solutions free of dissolved oxygen, other cations such as Ru(II) and Ti(III) can form a more stable bridge between the metal centre and one of the oxo groups of ClO−4. In the inner sphere electron transfer mechanism to observe the perchlorate reduction, the ClO−4 anion must quickly transfer an oxygen atom to the reducing cation. When it is the case, metallic cations can readily reduce perchlorate in solution. Ru(II) can reduce ClO−4 to ClO−3, while V(II), V(III), Mo(III), Cr(II) and Ti(III) can reduce ClO−4 to Cl−. Some metal complexes, especially those of rhenium, and some metalloenzymes can catalyze the reduction of perchlorate under mild conditions. Perchlorate reductase (see below), a molybdoenzyme, also catalyzes the reduction of perchlorate. Both the Re- and Mo-based catalysts operate via metal-oxo intermediates.
=== Other mammals === A number of other mammals also have a requirement for taurine. While the majority of dogs can synthesize taurine, case reports have described a singular American Cocker Spaniel, 19 Newfoundland dogs, and a family of Golden Retrievers suffering from taurine deficiency treatable with supplementation. Foxes on fur farms also appear to require dietary taurine. The rhesus, cebus and cynomolgus monkeys each require taurine at least in infancy. The giant anteater also requires taurine.
=== Formation of Haymarket === Despite Heseltine's later insistence on management controls in government departments which he ran, Cornmarket was a highly disorganised company, with little in the way of accounting or business plans and cheques and invoices often going astray. One of its most lucrative ventures, the Graduates Appointments Register (albums of anonymous graduate CV; companies had to pay for the names and addresses of those whom they wished to interview), went ahead after an employee simply ignored Heseltine's instructions to abandon the project. Heseltine and Labovitch brought a great deal of energy and openness to new ideas (for example the in-house magazine for Hilton Hotels, or new owners' packs for people who bought Ford cars), talent-spotting able young men and leaving it to them to sort out the details. Lindsay Masters, who had joined the Heseltine-Labovitch publishing business as an advertising manager in spring 1958, and Simon Tindall, who had joined in his early twenties as an advertising salesman while Heseltine had been doing his National Service, played an increasingly large role in managing the company. Masters kept a tight grip on the selling of advertising space, banning boozy lunches and setting targets for calling of clients, followed by chase-up calls, whilst keeping a public league table of salesmens' success rates; these were relatively innovative techniques at the time. By 1964, Cornmarket owed a great deal of money to their printers, Hazell Watson & Viney, which was then merging with the British Printing Corporation (BPC).
Sources: en.wikipedia.org
Very low bodyweight; Rapid weight loss, regardless of starting bodyweight; Medical comorbidities, such as infection or malabsorption; Excessive purging behaviours, including self-induced vomiting, laxative abuse, and diuretic abuse. Two of the most common indicators that RFS is occurring are low phosphate levels and low potassium levels. In these circumstances, it is recommended to start refeeding more slowly but to build up rapidly as long as RFS does not occur. Recommendations on energy requirements in the most medically compromised patients vary, from 5–10 kcal/kg/day to 1900 kcal/day. Treatment professionals must balance the risk of RFS with the risk of underfeeding, which can result in poor health outcomes for short- and long-term recovery.
==== Declined ==== Beto Altamirano, tech entrepreneur and candidate for mayor of San Antonio in 2025 Greg Casar, incumbent U.S. representative from the 35th district Philip Cortez, state representative from the 117th district (2013–2015, 2017–present) (running for re-election) Roland Gutierrez, state senator from the 19th district (2021–present) and candidate for U.S. senate in 2024 (running for re-election)
=== System III === Fungal, vertebrate and invertebrate mitochondria produce cytochrome c proteins with a single enzyme called HCCS (holocytochrome c synthase) or cytochrome c heme lyase (CCHL). The protein is attached to the inner membrane of the intermembrane space. In some organisms, such as Saccharomyces cerevisiae, cytochrome c and cytochrome c1 are synthesized by separate heme lyases, CCHL and CC1HL respectively. In Homo sapiens a single HCCS is used for the biosynthesis of both cytochrome c proteins.
Sources: en.wikipedia.org
Identity is normally confirmed by mass spectrometry, which checks the measured mass against the expected value near 390 daltons. Reverse-phase high-performance liquid chromatography is used alongside it to assess purity. Amino acid analysis can provide additional composition data.
The powder is generally kept refrigerated or frozen, protected from light and moisture. Vials should reach room temperature before opening to prevent condensation. Reconstituted solutions are usually stored cold and used within a limited window because dilute solutions can degrade or support microbial growth.
Epitalon is not an approved drug in major Western regulatory jurisdictions. Its legal status differs between countries, and it is often distributed as a research chemical. This means product documentation and purity vary considerably between suppliers.
No. Epithalamin is a peptide-containing extract of bovine pineal glands, while epitalon is a single synthetic tetrapeptide. The extract contains many peptides and other tissue components, so its composition varies between batches in ways that a synthesised sequence does not.