A practical reference on telomerase: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-07-26 and is reviewed periodically as new material appears.
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.
Reported biological findings come mainly from cell culture and rodent experiments. Those studies describe changes in telomerase catalytic subunit expression, melatonin rhythm amplitude, and antioxidant enzyme activity after peptide exposure. Human data are sparse and consist of small trials with limited blinding and inconsistent endpoints. The proposed mechanisms remain hypotheses rather than established facts, and there is no consensus on whether effects observed in animals carry over to people. Independent replication outside the original research groups is limited, which is a recognised gap in the published literature.
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.
The molecule is a short, linear, hydrophilic peptide that dissolves readily in water or aqueous buffer. Its principal chemical liabilities are hydrolytic rather than oxidative, since it contains no cysteine, methionine, or tryptophan residues. The aspartate–glycine step is a recognised site for aspartimide formation under mildly acidic or basic conditions, generating isoaspartate and succinimide-related products over time. Desiccated lyophilised powder held at −20 °C is comparatively stable, whereas dilute solutions degrade faster and are best frozen as single-use aliquots rather than thawed repeatedly.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic tetrapeptide | Four amino acid residues |
| Residue sequence | Ala-Glu-Asp-Gly | Abbreviated AEDG |
| Approximate mass | 390.35 Da | Monoisotopic, free base form |
| Parent preparation | Epithalamin extract | Derived from pineal tissue |
| Common spelling variants | Epithalon, epithalone, AEDG | Affects literature retrieval |
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.
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.
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.
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.
Laboratory-grade epitalon is typically supplied as a lyophilized powder. Purity is commonly assessed with reverse-phase high-performance liquid chromatography, often paired with mass spectrometry to confirm molecular identity. Amino acid analysis and peptide mapping can provide additional confirmation of sequence. Certificates of analysis for research materials frequently report purity above 95 percent, although the methods behind such figures vary between suppliers. The absence of a pharmacopeial monograph means that no single standardized assay defines the compound, so reported results depend on the analytical protocol chosen.
The authors conclude that past respiratory disorders maximally contribute to IPF risk, followed by known IPF comorbidities, metabolic diseases, cardiovascular abnormalities, and diseases of the eye, with the overall pattern of the importance ranking substantially invariant across the sexes.
Naval Postgraduate School academic Edward A. Olsen, British politician David Alton, York University professor Hyun Ok Park, and University of Southern California professor David C. Kang used the term to refer to tensions between North Korea and South Korea, which have been divided since the end of World War II in 1945. They interchangeably called it the "Korean Cold War". In August 2019, the North Korean government said that further US–South Korean military cooperation would prompt North Korea to "trigger a new cold war on the Korean Peninsula and in the region." China's Defense Ministry spokesman Geng Yansheng, The Diplomat editor Shannon Tiezzi, and The Guardian columnist Simon Tisdall used the term to refer to tensions between China and Japan.
Hygiene, e.g. measured by number of micro-organisms per mL of finished product. Energy efficiency measured e.g. by "tonnes of steam per ton of sugar produced". Minimization of waste, measured e.g. by "percentage of peeling loss during the peeling of potatoes". Labour used, measured e.g. by "number of working hours per ton of finished product". Minimization of cleaning stops measured e.g. by "number of hours between cleaning stops".
=== Sandia National Laboratories and implantable insulin pump development === In parallel with early academic and commercial efforts, significant development of implantable insulin delivery systems was carried out at Sandia National Laboratories in collaboration with the University of New Mexico School of Medicine during the late 1970s and early 1980s. This work focused on the design of an electronically controlled, remotely programmable insulin infusion system intended to more closely replicate the physiological function of the human pancreas. The Sandia–UNM system built upon earlier external insulin pumps and incorporated engineering approaches derived from high-reliability systems, including precise flow control and programmable delivery rates. The implantable device was tested in animal models and subsequently implanted in human patients beginning in January 1981, with additional implantations reported in early 1982. Key engineering contributions to the system were made by a multidisciplinary team at Sandia, including Gary A. Carlson, Raymond E. Bair, John I. Gaona Jr., Jerry T. Love, and Ruben S. Urenda, who co-authored foundational technical reports describing the design and operation of the implantable, remotely programmable insulin infusion system. Earlier engineering work on insulin delivery systems by members of the Sandia–UNM collaboration was also described in peer-reviewed literature, including analysis of system design considerations such as flow control, programmability, and reliability.
Sources: en.wikipedia.org
== Adverse effects == Adverse drug reactions (ADRs) are rare when lidocaine is used as a local anesthetic and is administered correctly. Most ADRs associated with lidocaine for anesthesia relate to administration technique (resulting in systemic exposure) or pharmacological effects of anesthesia, and allergic reactions only rarely occur. Systemic exposure to excessive quantities of lidocaine mainly results in central nervous system (CNS) and cardiovascular effects – CNS effects usually occur at lower blood plasma concentrations and additional cardiovascular effects present at higher concentrations, though cardiovascular collapse may also occur with low concentrations. ADRs by individual organ systems are:
=== Degrees === Petechiae – small pinpoint hematomas less than 3 mm in diameter; Purpura (purple) – a bruise about 3–10 mm in diameter, generally round in shape; Ecchymosis – subcutaneous extravasation of blood in a thin layer under the skin, i.e. bruising, over 1 cm in diameter.
== Types == Types include those acting directly as membrane-bound receptors (Receptor protein serine/threonine kinase) and intracellular kinases participating in Signal transduction. Of the latter, types include:
Oligonucleotides are short DNA or RNA molecules, oligomers, that have a wide range of applications in genetic testing, research, and forensics. Commonly made in the laboratory by solid-phase chemical synthesis, these small fragments of nucleic acids can be manufactured as single-stranded molecules with any user-specified sequence, and so are vital for artificial gene synthesis, polymerase chain reaction (PCR), DNA sequencing, molecular cloning and as molecular probes. In nature, oligonucleotides are usually found as small RNA molecules that function in the regulation of gene expression (e.g. microRNA), or are degradation intermediates derived from the breakdown of larger nucleic acid molecules. Oligonucleotides are characterized by the sequence of nucleotide residues that make up the entire molecule. The length of the oligonucleotide is usually denoted by "-mer" (from Greek meros, "part"). For example, an oligonucleotide of six nucleotides (nt) is a hexamer, while one of 25 nt would usually be called a "25-mer". Oligonucleotides readily bind, in a sequence-specific manner, to their respective complementary oligonucleotides, DNA, or RNA to form duplexes or, less often, hybrids of a higher order. This basic property serves as a foundation for the use of oligonucleotides as probes for detecting specific sequences of DNA or RNA. Examples of procedures that use oligonucleotides include DNA microarrays, Southern blots, ASO analysis, fluorescent in situ hybridization (FISH), PCR, and the synthesis of artificial genes.
=== Congressional testimony === In June 2025, Powell testified before Congress regarding the renovation project. Under questioning, he denied that the current plans included luxury features such as VIP dining rooms, special elevators, or new marble installations, stating that existing marble was being reused where possible and that certain earlier proposals had been eliminated as plans evolved. Following the hearing, the Federal Reserve published a “Frequently Asked Questions” document and released additional materials, including photographs and annotated planning documents, reaffirming Powell’s testimony and explaining changes to the project over time. Critics argued that Powell’s testimony conflicted with earlier planning documents, raising questions about whether his statements were misleading. Powell has maintained that his answers accurately reflected the project as it existed at the time of his testimony. In July 2025, U.S. Representative Anna Paulina Luna of Florida made a criminal referral to the Justice Department over Powell's testimony to the Senate Banking Committee the previous month.
Sources: en.wikipedia.org
==== Immunohistochemistry Approaches ==== As an antibody technique, immunohistochemistry (IHC) allows for validating protein presence. It, and immunocytochemistry, allow for surveying the localization of proteases on a tissue or cellular scale respectively. It also can evaluate for the localization of cleavage products using monoclonal antibodies raised against neo-epitopes of cleavage sites produced by protease processing. Unfortunately, in addition to providing little functional information, IHC is also non-quantitative, making it an unappealing option for describing degradomics on system-wide scales.
The gateway hypothesis states that cannabis use increases the probability of trying "harder" drugs. The hypothesis has been hotly debated as it is regarded by some as the primary rationale for the United States prohibition on cannabis use. A Pew Research Center poll found that political opposition to marijuana use was significantly associated with concerns about the health effects and whether legalization would increase cannabis use by children. Some studies state that while there is no proof for the gateway hypothesis, young cannabis users should still be considered as a risk group for intervention programs. Other findings indicate that hard drug users are likely to be poly-drug users, and that interventions must address the use of multiple drugs instead of a single hard drug. Almost two-thirds of the poly drug users in the 2009–2010 Scottish Crime and Justice Survey used cannabis. The gateway effect may appear due to social factors involved in using any illegal drug. Because of the illegal status of cannabis, its consumers are likely to find themselves in situations allowing them to acquaint with individuals using or selling other illegal drugs. Studies have shown that alcohol and tobacco may additionally be regarded as gateway drugs; however, a more parsimonious explanation could be that cannabis is simply more readily available (and at an earlier age) than illegal hard drugs.
Retinal dystrophy (cone-rod dystrophy) in all cases, usually within a few weeks of birth and progressively worsening until about 20 years of age when vision is lost. Nystagmus (often one of the first symptoms identified) and photophobia are also very common. Mild to moderate progressive bilateral sensorineural hearing loss. Hearing impairment is typically diagnosed between the ages of 1 and 10. Congestive heart failure (dilated cardiomyopathy) in over 60% of individuals over the course of their lifetimes. Around 40% of individuals suffer from a severe cardiomyopathy within the first few months of life. For those who survive, cardiomyopathy occurs in 1 of 5 patients with onset in adolescence or adulthood. Hypothyroidism tends to occur in less than half of patients. Growth hormone dysfunction is common in around half of individuals with AS. Thoracic and lumbar scoliosis, kyphosis, or lordosis is present in around 68% of patients. Male hypergonadotropic and hypogonadotropic hypogonadism and female hyperandrogenism. Men can experience microphallus, undescended testes, hypospadias, small testes, and gynecomastia. They are also unlikely to be fertile. Women can experience hirsutism, alopecia, oligomenorrhea/amenorrhea, polycystic ovaries, high testosterone levels, abnormal breast development, precocious puberty, and endometriosis. Female fertility is unlikely and only reported in a few cases. Childhood obesity occurs in most people with AS. Alström infants are usually within the normal birth weight and then experience rapid weight gain within the first 2–36 months.
Tetrahymanol is a gammacerane-type membrane lipid first found in the marine ciliate Tetrahymena pyriformis. It was later found in other ciliates, fungi, ferns, and bacteria. After being deposited in sediments that compress into sedimentary rocks over millions of years, tetrahymanol is dehydroxylated into gammacerane. Gammacerane has been interpreted as a proxy for ancient water column stratification.
== Disease relevance == E3 ubiquitin ligases regulate homeostasis, cell cycle, and DNA repair pathways, and as a result, a number of these proteins are involved in a variety of cancers, including famously MDM2, BRCA1, and Von Hippel-Lindau tumor suppressor. For example, a mutation of MDM2 has been found in stomach cancer, renal cell carcinoma, and liver cancer (amongst others) to deregulate MDM2 concentrations by increasing its promoter's affinity for the Sp1 transcription factor, causing increased transcription of MDM2 mRNA. Several proteomics-based experimental techniques are available for identifying E3 ubiquitin ligase-substrate pairs, such as proximity-dependent biotin identification (BioID), ubiquitin ligase-substrate trapping, and tandem ubiquitin-binding entities (TUBEs).
Sources: en.wikipedia.org
It is based on epithalamin, a peptide-rich preparation obtained from pineal gland tissue and studied in the former Soviet Union. Researchers later identified the tetrapeptide AEDG as a constituent fragment of that material. Modern supplies are produced by chemical synthesis rather than tissue extraction.
No. Epithalamin is a heterogeneous extract containing many peptides, while epitalon is a single synthesised tetrapeptide. Publications sometimes treat findings from the two as equivalent, which is a common source of confusion. Their compositions differ and they are not interchangeable in analytical terms.
Most published work uses cell cultures or rodents because those models are faster and less costly to run. The few human trials that have been reported are small, and several lack control groups or blinding. This restricts what can reasonably be concluded about effects in people.
Mass spectrometry provides the identity check, because the observed mass is compared with the theoretical mass of the AEDG sequence. Chromatography separates and quantifies impurities but does not by itself prove which peptide is present. The two techniques are normally used together.