If you have been reading about Reversed-phase HPLC 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 2026-08-01. Where a claim depends on a specific study, the study is described rather than over-claimed.
Animal and clinical reports appear mainly in Russian-language journals from the 1990s and 2000s, covering endpoints such as melatonin rhythm, lifespan in aged rodents, and retinal function. Many of these papers involve small groups, lack blinding or placebo comparison, and are difficult to retrieve through indexed databases. Review articles published in English generally summarise the claims without reanalysing the underlying data. Because no large randomised trial exists, the clinical importance of these reported effects stays unresolved and is properly described as an open question.
No national medicines regulator has approved epitalon as a therapeutic product. It is generally distributed as a research chemical, and in some jurisdictions selling peptides for human consumption without approval is restricted or prohibited. Certificates of analysis accompanying commercial material vary in which tests are performed, and independent verification of identity and purity is uncommon. Statements about anti-ageing or disease-prevention benefits on vendor pages are marketing claims rather than regulatory findings, a distinction that shapes how the compound is discussed in scientific and popular sources alike.
The most frequently cited laboratory finding is that AEDG increased telomerase activity and extended telomere length in cultured human somatic cells. That work used fetal fibroblast strains and reported changes in enzyme activity alongside altered division counts. Replication by unrelated groups has been limited, and the published record is largely a single-laboratory series rather than a multi-centre programme. The result supports a hypothesis about peptide influence on gene expression in cell culture; it does not by itself establish an effect on telomere length in living animals or in people.
Epitalon is a synthetic tetrapeptide whose four residues are alanine, glutamate, aspartate and glycine, commonly abbreviated AEDG. Its molecular formula is C14H22N4O9 and its monoisotopic mass is near 390.35 daltons. The peptide carries two acidic side chains, so it is neutral to negatively charged in most aqueous buffers. Published reference summaries usually list it under both spellings, epitalon and epithalon, and treat the two names as the same material.
The compound is generally described as a synthetic analogue of a fragment isolated from a pineal gland extract. Researchers associated with the Saint Petersburg Institute of Bioregulation and Gerontology introduced it during the 1980s and 1990s while studying short peptides from animal tissue. The original extract, called epithalamin, is a heterogeneous mixture, whereas epitalon is a single defined sequence. That distinction matters because findings reported for the extract are not automatically findings about the pure tetrapeptide, and claims about broader biological effects remain a separate question from the chemical identity described here.
| Property | Value | Notes |
|---|---|---|
| Regulatory status | Not an approved drug | Marketed in most countries as a research chemical |
| Main literature language | Russian and English | Early reports concentrated in Russian journals |
| Typical stated purity | ≥95% by HPLC | Supplier declaration, seldom independently verified |
| Principal studied endpoint | Telomerase activity in vitro | Measured in cultured human cells |
| Reported administration routes | Subcutaneous, intranasal | Described in exploratory use reports |
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.
Epitalon appears in the literature primarily through a small number of research groups, most of them associated with the St. Petersburg Institute of Bioregulation and Gerontology. Publications describe cell culture experiments, animal studies, and a limited number of small human studies. Independent replication outside this network is sparse. As a result, reviews of the topic usually separate descriptive reports of observed effects from the question of whether those effects generalize, and they note the difficulty of comparing studies that use different preparations and endpoints.
Analytical characterization of epitalon relies on standard peptide methods. Reverse-phase high-performance liquid chromatography is used to assess purity, and mass spectrometry confirms identity by checking the observed mass against the expected value near 390 daltons. Amino acid analysis can verify composition. Because the peptide is short and hydrophilic, it elutes early on many reverse-phase columns, so method development often requires ion-pairing reagents to achieve adequate retention and resolution from related impurities.
Chemically, the molecule consists of four amino acid residues joined by three peptide bonds, with a free N-terminal amino group and a free C-terminal carboxyl group. Its molecular formula is C14H22N4O9, and its monoisotopic mass is approximately 390 daltons. The acidic glutamate and aspartate side chains give the peptide a net negative charge near neutral pH, a property that shapes its chromatographic behaviour and solubility profile. No disulfide bridges or other post-translational modifications are present, so the primary sequence alone defines the structure.
Most experimental work has been carried out in cell culture and animal models. Several reports describe changes in telomerase activity and proliferation in cultured cells, while rodent studies have examined lifespan, melatonin rhythm and reproductive endpoints. Human data remain limited, and much of the published clinical material consists of small trials with incomplete reporting of methods and controls. Whether the cell and animal findings translate into measurable effects in people is an open question, and the mechanistic basis of the reported telomerase changes is not fully established.
Discussions in the literature often conflate three distinct entities: the pineal extract epithalamin, the isolated tetrapeptide AEDG, and commercial preparations sold under similar names. Reviews citing older Russian-language studies sometimes omit detail on purity, route of administration and control groups, which makes cross-study comparison difficult. Researchers working with the compound generally note the need for independent replication, standardized enzyme assays, and clearer reporting of peptide identity. These caveats are relevant when weighing claims that appear in secondary sources rather than in primary reports.
Stability of the tetrapeptide follows ordinary peptide chemistry rather than any unusual structural feature. The aspartate-glycine pair is prone to aspartimide formation under mildly basic or neutral conditions, and deamidation can follow, altering both mass and chromatographic retention. Dry lyophilised powder kept at or below minus twenty degrees Celsius is the usual handling recommendation, with repeated freeze-thaw cycles avoided. Once dissolved in neutral aqueous buffer, degradation proceeds over days to weeks depending on pH and temperature, while acidic conditions generally slow the aspartimide route. A formal stability-indicating study has not been published in the indexed literature.
Because epitalon has no pharmacopoeial monograph, quality assessment depends on supplier documentation and independent testing. Certificates of analysis typically report a purity figure from a single chromatographic run, a measured mass and sometimes an appearance description, but methods and acceptance criteria are not harmonised across vendors. Third-party laboratories can repeat identity and purity measurements, and mismatches between labelled and measured peptide content have been described for research peptides generally. What constitutes adequate identity confirmation for a molecule of this size stays an open question, since mass agreement alone does not separate closely related sequences.
Identity testing for epitalon relies on reversed-phase high-performance liquid chromatography for purity and mass spectrometry for mass confirmation. Because the sequence contains no tryptophan or tyrosine, ultraviolet detection at 280 nanometres is insensitive, so chromatographic methods usually monitor absorbance near 214 nanometres, where the peptide backbone absorbs. Electrospray ionisation or matrix-assisted laser desorption/ionisation then checks the intact mass against the expected value near 390 daltons. Peptide mapping or amino acid analysis after acid hydrolysis can supplement these measurements, although such confirmatory work is seldom reported on commercial certificates of analysis.
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.
== Synthesis == Cyclodextrins are prepared by enzymatic treatment of starch. Commonly cyclodextrin glycosyltransferase (CGTase) is employed along with α-amylase. First starch is liquified either by heat treatment or using α-amylase, then CGTase is added for the enzymatic conversion. CGTases produce mixtures of cyclodextrins, thus the product of the conversion results in a mixture of the three main types of cyclic molecules, in ratios that are strictly dependent on the enzyme used: each CGTase has its own characteristic α:β:γ synthesis ratio. Purification of the three types of cyclodextrins takes advantage of the different water solubility of the molecules: β-CD which is poorly water-soluble (18.5 g/L or 16.3 mM at 25 °C) can be easily retrieved through crystallization while the more soluble α- and γ-CDs (145 and 232 g/L respectively) are usually purified by means of expensive and time consuming chromatography techniques. As an alternative a "complexing agent" can be added during the enzymatic conversion step: such agents (usually organic solvents like toluene, acetone or ethanol) form a complex with the desired cyclodextrin which subsequently precipitates. The complex formation drives the conversion of starch towards the synthesis of the precipitated cyclodextrin, thus enriching its content in the final mixture of products. Some researchers have developed dedicated processes that can produce alpha-, beta- or gamma-cyclodextrin specifically.
== Therapeutic potential == In a test of pharmacologic asprosin depletion in animals, preliminary results raised the possibility of its use, therapeutically, in treating type 2 diabetes and obesity. For instance, Chopra and coworkers observed that when monoclonal antibodies targeting asprosin were injected into diabetic mice, blood glucose and insulin levels improved.
Under Guzmán, the Sinaloa Cartel fought the Juárez Cartel in a prolonged battle for control over drug trafficking routes in and around Ciudad Juárez. The battle resulted in defeat for the Juárez Cartel, resulting in the deaths of between 5,000 and 12,000 people. The Sinaloa Cartel used several gangs (e.g. Los Mexicles, the Artistas Asesinos and Gente Nueva) to attack the Juárez Cartel. The Juárez Cartel similarly used gangs such as La Línea and the Barrio Azteca to fight the Sinaloa Cartel. In February 2010, the Federation formed new alliances against Los Zetas and the Beltrán-Leyva Cartel. Guzmán was arrested and escaped in 2015, re-arrested in 2016, and extradited to the U.S. in 2017. Guzmán claimed that he had paid former presidents Enrique Peña Nieto and Felipe Calderón bribes, which both denied. In 2019, he was convicted of drug trafficking and sentenced to life imprisonment, after which Ismael "El Mayo" Zambada emerged as the cartel's senior figure. Zambada was arrested in 2024 and extradited to the U.S. in 2025. In January 2023, the arrest of Guzmán's son Ovidio Guzmán sparked a wave of violence in the state of Sinaloa, with the military deploying aircraft and heavy forces in response. Following the arrests of Guzmán and Zambada, the Sinaloa Cartel has experienced infighting, with rival factions aligning under their respective names. In February 2026, the U.S. State Department says it will pay up to $10 million for information leading to the arrests or convictions of two brothers identified as leaders of Mexico's Sinaloa cartel in the state of Baja California.
Sources: en.wikipedia.org
== Further reading == Lampe, Markus, and Paul Sharp. A Land of Milk and Butter: How Elites Created the Modern Danish Dairy Industry (U of Chicago Press, 2018) online review Boberg-Fazlic, Nina; Jensen, Peter Sandholt; Lampe, Markus; Sharp, Paul; Skovsgaard, Christian Volmar (2023). "'Getting to Denmark': the role of agricultural elites for development". Journal of Economic Growth. 28 (4): 525–569. Kærgård, Niels (2023). "The Danish Economy, 1973–2009: From National Welfare State to International Market Economy". Scandinavian Journal of History
Conventionally, a definitive diagnosis requires a demonstration of depleted body iron stores obtained by bone marrow aspiration, with the marrow stained for iron. However, with the availability of reliable blood tests that can be more readily collected for iron-deficiency anemia diagnosis, a bone marrow aspiration is usually not obtained. Furthermore, a study published in April 2009 questions the value of stainable bone marrow iron following parenteral iron therapy. Once iron deficiency anemia is confirmed, gastrointestinal blood loss is presumed to be the cause until proven otherwise since it can be caused by an otherwise asymptomatic colon cancer. The initial evaluation must include esophagogastroduodenoscopy and colonoscopy to evaluate for cancer or bleeding of the gastrointestinal tract. A thorough medical history is important to diagnose iron-deficiency anemia. The history can help to differentiate common causes of the condition, such as menstruation in women or blood in the stool. A travel history to areas in which hookworms and whipworms are endemic may also help guide certain stool tests for parasites or their eggs. Although symptoms can play a role in identifying iron-deficiency anemia, they are often vague, which may limit their contribution to determining the diagnosis.
The Ranger program, started in 1959 by NASA's Jet Propulsion Laboratory, aimed to conduct hard impacts on the Moon and had its first success in 1962, after three failures due to launch aborts (Ranger 1 and Ranger 2) and a failure to reach the Moon (Ranger 3), when the 730-pound (330 kg) Ranger 4 became the first US spacecraft to reach the Moon, but its solar panels and navigational system failed near the Moon and it impacted the far side without returning any scientific data. Ranger 5 ran out of power and missed the Moon by 725 kilometers (391 nmi) on October 21, 1962. The first successful Ranger mission was the 806-pound (366 kg) Block III Ranger 7 which impacted on July 31, 1964. Ranger had three successful impacts out of nine attempts. In 1963, the Soviet Union's "2nd Generation" Luna programme was less successful than the earlier Luna probes; Luna 4, Luna 5, Luna 6, Luna 7, and Luna 8 were all met with mission failures. However, in 1966 the Luna 9 achieved the first soft-landing on the Moon, and successfully transmitted photography from the surface. Luna 10 marked the first man-made object to establish an orbit around the Moon, followed by Luna 11, Luna 12, and Luna 14 which also successfully established orbits. Luna 12 was able to transmit detailed photography of the surface from orbit. Luna 10, 12, and Luna 14 conducted Gamma ray spectrometry of the Moon, among other tests. The Zond programme was orchestrated alongside the Luna programme with Zond 1 and Zond 2 launching in 1964, intended as flyby missions, however both failed.
In Pakistan, all sexual activity outside of marriage is illegal. The punishment for sex outside marriage (zina) ranges from up to five years' imprisonment for minors to 100 lashes for unmarried adults and stoning to death for married adults, depending on marital status, age, sanity, and whether strict evidentiary requirements for a hadd punishment—such as four adult male Muslim witnesses or a confession—are met; however, no one has been stoned to death under the law to date. Male homosexuality is illegal in Pakistan and is punishable by up to ten years in prison, corporal punishment such as whipping, and, under Islamic law since 1990, potentially even stoning. Honour killings, locally referred to as karo-kari in parts of Pakistan, involve the killing of women and, less frequently, men by family or community members over alleged extramarital relationships or perceived violations of honour. Human rights organisations report that hundreds of women are killed each year, with many cases unreported. Pakistan also has a high number of reported acid attacks, with about 200 incidents annually as of 2023, most victims being women. According to Masarrat Misbah, founder of the Depilex Smileagain Foundation, women have been targeted for rejecting marriage proposals, giving birth to daughters instead of sons, or insufficient dowry. The 2011 Acid and Burn Crime Bill criminalised acid attacks, making them punishable by lengthy imprisonment and fines. In parts of Pakistan, girls are given in marriage to settle disputes or crimes between families in a customary practice called Vani.
Sources: en.wikipedia.org
Small studies with human participants have been reported, chiefly in Russian-language journals, but they are limited in size and design. No large randomised controlled trial with published results is available.
The most reproducible biochemical observation comes from cultured cells, where the peptide was reported to raise telomerase activity. Whether this translates into measurable health effects in animals or humans is not established.
It is offered as a research chemical for laboratory use, which places it outside the approval pathways applied to medicines. Buyers should expect documentation to differ between suppliers.
It is a four-amino-acid peptide built from alanine, glutamate, aspartate and glycine in that order. Its formula is C14H22N4O9, and it is made by chemical synthesis rather than extracted from tissue. The synthetic peptide is a single defined molecule, unlike the pineal extracts it is often compared with.