This is a working overview of Tetrapeptide, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-06-25 and is reviewed periodically as new material appears.
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.
The compound is generally presented as a synthetic fragment of epithalamin, a pineal gland extract investigated in the former Soviet Union from the 1970s onward. Vladimir Khavinson and colleagues in Saint Petersburg developed short peptides modelled on such extracts, and epitalon became the most widely cited of those sequences. Most primary reports appeared in Russian-language journals or in proceedings with limited international circulation. Independent replication in laboratories outside that network remains sparse, and much repeated secondary material traces back to a small number of originating groups.
Laboratory work has examined effects on telomerase activity in cultured cells, on melatonin rhythms in animals, and on markers of oxidative stress. Some experiments report measurable changes while others show none, and the reported findings rest largely on small studies. The absence of large independent trials means the generality of these results is unresolved rather than settled. Review articles occasionally apply the label geroprotector, a term that reflects a research hypothesis about ageing rather than an established clinical finding.
Epitalon is the common name for a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, usually abbreviated AEDG. All four residues are proteinogenic amino acids, and the free peptide has a calculated mass near 390 grams per mole. Because the chain is short and carries no modifications, it is assembled readily by solid-phase synthesis and is distributed mainly as a freeze-dried solid for laboratory work. Catalogue listings use the spellings epitalon, epithalone, and simply AEDG, and the three refer to the same sequence.
| 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.
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 is a synthetic tetrapeptide with the sequence alanine–glutamate–aspartate–glycine, commonly abbreviated AEDG. Its design traces to epithalamin, a peptide fraction prepared from bovine pineal gland extracts that researchers in Saint Petersburg began investigating in the 1970s. The compound has a molecular formula of C14H22N4O9 and a nominal molecular mass near 390 daltons. It holds no approved drug status in the United States or the European Union, and material sold under this name is generally offered as a research chemical rather than a finished pharmaceutical product.
Proposed mechanisms centre on cell-culture observations rather than a defined receptor interaction. Several reports describe increased expression of the telomerase catalytic subunit after exposure of cultured human cells, and the authors attributed the effect to short peptide fragments entering the nucleus and influencing gene transcription. No receptor for the tetrapeptide has been identified, and the free peptide is expected to be degraded rapidly by plasma peptidases. Whether any measurable fraction reaches intact tissues after administration remains an unresolved question rather than an established finding.
The published literature is dominated by a small number of research groups, much of it in Russian-language journals, and independent replication outside those groups is limited. Studies are typically small, use cultured cells or rodent models, and report endpoints that differ between papers, which makes comparison difficult. Large randomised human trials have not appeared in the indexed literature. Questions about absorption, distribution and clearance are therefore still treated as open in reviews that mention the compound.
==== Role in cancer ==== In 1863, Rudolf Virchow hypothesized that the origin of cancer was at sites of chronic inflammation. As of 2012, chronic inflammation was estimated to contribute to approximately 15% to 25% of human cancers.
=== Initial adoption === Due to the influence tire pressure has on vehicle safety and efficiency, tire-pressure monitoring (TPM) was adopted by the European market as an optional feature for luxury passenger vehicles in the 1980s. The first passenger vehicle to adopt TPM was the Porsche 959 in 1986, using a hollow spoke wheel system developed by PSK. In 1996 Renault used the Michelin PAX system for the Scenic and in 1999 PSA Peugeot Citroën decided to adopt TPM as a standard feature on the Peugeot 607. The following year (2000), Renault launched the Laguna II, the first high volume mid-size passenger vehicle in the world to be equipped with TPM as a standard feature. In the United States, TPM was introduced by General Motors for the 1991 model year for the Corvette in conjunction with Goodyear run-flat tires. The system uses sensors in the wheels and a driver display which can show tire pressure at any wheel, plus warnings for both high and low pressure. It has been standard on Corvettes ever since.
=== Sale in Japan === The alcoholic beverage industry in Japan is large. For example, in fiscal year 2013, Suntory, one of the country's largest beverage companies, recorded sales of 570.7 billion yen (about US$4.7 billion) in alcoholic beverages, excluding wine. Currently, the sales revenue from powdered alcohol has been too small to affect the sales of liquid-alcohol companies. Additionally, powdered alcohol's market share is currently too small to be considered as a statistical item in Japanese tax reports. Powdered alcohol is found in some mass production foods, used in small amounts (as are other additives).
Hypoglycemia (American English), also spelled hypoglycaemia or hypoglycæmia (British English), sometimes called low blood sugar, is a fall in blood sugar to levels below normal, typically below 70 mg/dL (3.9 mmol/L). Whipple's triad is used to properly identify hypoglycemic episodes. It is defined as blood glucose below 70 mg/dL (3.9 mmol/L), symptoms associated with hypoglycemia, and resolution of symptoms when blood sugar returns to normal. Hypoglycemia may result in headache, tiredness, clumsiness, trouble talking, confusion, fast heart rate, sweating, shakiness, nervousness, hunger, loss of consciousness, seizures, or death. Symptoms typically come on quickly. Symptoms can persist after blood-glucose levels are restored to normal. The most common cause of hypoglycemia is medications used to treat diabetes such as insulin, sulfonylureas, and biguanides. Risk is greater in people with diabetes who have eaten less than usual, recently exercised, or consumed alcohol. Other causes of hypoglycemia include severe illness, sepsis, kidney failure, liver disease, hormone deficiency, tumors such as insulinomas or non-B cell tumors, inborn errors of metabolism, and several medications. Low blood sugar may occur in otherwise healthy newborns who have not eaten for a few hours. Hypoglycemia is treated by eating a sugary food or drink, for example glucose tablets or gel, apple juice, soft drinks, or lollipops. The person must be conscious and able to swallow. The goal is to consume 10–20 grams of a carbohydrate to raise blood glucose levels to a minimum of 70 mg/dL (3.9 mmol/L).
Sources: en.wikipedia.org
==== Estrogens (estrogen receptor agonists) ==== Conjugated estrogens (conjugated equine estrogens; CEEs; Premarin) – estrogen (estrogen receptor agonist) – atrophic vaginitis, dyspareunia [132] Conjugated estrogens oral (Enjuvia; synthetic conjugated estrogens) – estrogen (estrogen receptor agonists) – atrophic vaginitis [133] Conjugated estrogens/bazedoxifene (Aprela; bazedoxifene acetate/conjugated estrogens; bazedoxifene/conjugated estrogens; bazedoxifene/Premarin; BZA/CE; CE/BZA; conjugated estrogens/bazedoxifene acetate; Duavee; Duavive; Premarin/bazedoxifene; SERM + Premarin) – combination of conjugated estrogens (estrogen) and bazedoxifene (selective estrogen receptor modulator (SERM)) – atrophic vaginitis [134] Estradiol (Estrofem; Innofem; oral estradiol; Vagifem; vaginal estradiol) – estrogen (estrogen receptor agonist) – atrophic vaginitis [135] Estradiol transdermal micro patch (Estradot; Minivelle; Vivelle-Dot) – estrogen (estrogen receptor agonist) – atrophic vaginitis [136] Estradiol vaginal (E2; 17β-estradiol; Estradiol VagiCap; Imvexxy; Joyesta; TX-12-004-HR; TX-004HR; VagiCap; Yuvvexy) – estrogen (estrogen receptor agonist) – atrophic vaginitis [137] Estradiol acetate (Estrace; estradiol acetate intravaginal ring; estradiol acetate IVR; Femring; Menoring) – estrogen (estrogen receptor agonist) – atrophic vaginitis [138] Estriol succinate vaginal gel (6α-hydroxyestradiol; Blissel; Gelistrol) – estrogen (estrogen receptor agonist) – atrophic vaginitis [139] Estriol/lactobacillus (estriol-Lactobcillus acidophilus mixt.; estriol/lyophilised lactobacilli; Gynoflor; ultra-low dose estrogen/lactobacillus) – combination of estriol (estrogen) and lactobacillus (probiotic) – atrophic vaginitis [140] Ospemifene (FC-1271a; Ophena; Osphena; Senshio) – selective estrogen receptor modulator (SERM) – atrophic vaginitis, dyspareunia [141]
=== Age === Type 2 diabetes in youth brings a much higher prevalence of complications like diabetic kidney disease, retinopathy and peripheral neuropathy than type 1 diabetes, though no significant difference in the odds of arterial stiffness and hypertension.
Using any part of a living organism Protein purification involves the isolation of a specific protein of interest from a complex mixture of proteins, often obtained from homogenized cells or tissues. Using parts derived from multicellular organisms (cell culture, tissue culture, and more) In vitro fertilization is used to allow spermatozoa to fertilize eggs in a culture dish before implanting the resulting embryo or embryos into the uterus of the prospective mother. In vitro diagnostics refers to a wide range of medical and veterinary laboratory tests that are used to diagnose diseases and monitor the clinical status of patients using samples of blood, cells, or other tissues obtained from a patient. In vitro pharmacological testing has been used to characterize specific adsorption, distribution, metabolism, and excretion processes of drugs or general chemicals inside a living organism; for example, Caco-2 cell experiments can be performed to estimate the absorption of compounds through the lining of the gastrointestinal tract; The partitioning of the compounds between organs can be determined to study distribution mechanisms; Suspension or plated cultures of primary hepatocytes or hepatocyte-like cell lines (Hep G2, HepaRG) can be used to study and quantify metabolism of chemicals. These ADME process parameters can then be integrated into so called "physiologically based pharmacokinetic models" or PBPK. Cellular models of neurodegenerative diseases allow different ways to probe the health of the mitochondria in the cell. Using cellular or subcellular extracts (e.g.
Sources: en.wikipedia.org
=== Dietary recommendations === The US Institute of Medicine (IOM) updated Estimated Average Requirements (EARs) and Recommended Dietary Allowances (RDAs) for selenium in 2000. If there is not sufficient information to establish EARs and RDAs, an estimate designated Adequate Intake (AI) is used instead. The current EAR for selenium for people ages 14 and up is 45 μg/day. The RDA is 55 μg/day. RDAs are higher than EARs so as to identify amounts that will cover people with higher-than-average requirements. RDA for pregnancy is 60 μg/day. RDA for lactation is 70 μg/day. For children ages 1–13 years, the RDA increases with age from 20 to 40 μg/day. As for safety, the IOM sets Tolerable upper intake levels (ULs) for vitamins and minerals when evidence is sufficient. In the case of selenium, the UL is 400 μg/day. Collectively the EARs, RDAs, AIs and ULs are referred to as Dietary Reference Intakes (DRIs). The European Food Safety Authority (EFSA) refers to the collective set of information as Dietary Reference Values, with Population Reference Intake (PRI) instead of RDA, and Average Requirement instead of EAR. AI and UL are defined the same as in the United States. For women and men ages 15 and older, the AI is set at 70 μg/day. AI for pregnancy is 70 μg/day; for lactation, 85 μg/day. For children ages 1–14 years, the AIs increase with age from 15 to 55 μg/day. These AIs are higher than the U.S. RDAs. The European Food Safety Authority reviewed the same safety question and set its UL at 300 μg/day, which is lower than the U.S. value.
==== Allergic conditions ==== Setipiprant binds to the DP2 receptor with a dissociation constant of 6 nM, representing potent antagonism of the receptor. The DP2 receptor, also called the CRTh2 receptor, is a G-protein-coupled receptor (GPCR) that is expressed on certain inflammatory cells, such as eosinophils, basophils, and certain lymphocytes. For its mechanism of action in the treatment of allergic conditions, setipiprant's DP2 antagonism prevents the action of prostaglandin D2 (PGD2) on these receptors. The DP2 receptor mediates the activation of type 2 helper T (Th2) cells, eosinophils, and basophils in the lungs, which are white blood cells implicated in producing the inflammatory response the characterizes allergic conditions. Activation of DP2 on Th2 cells by PGD2 induces the secretion of inflammatory cytokines (interleukin (IL) 4, IL-5, and IL-13), which cause an increase of eosinophils in the blood, remodeling of lung tissue, and hypersensitivity of lung tissue to allergens. Setipiprant does not antagonize the thromboxane receptor (TP). The bronchoconstricting properties of PGD2 are not inhibited by setipiprant, since these are mediated by the TP receptor. As a point of contrast, ramatroban is a selective TP antagonist and DP2 receptor antagonist. Setipiprant does not appreciably inhibit the activity of the enzyme cyclooxygenase 1 (COX-1), which is responsible for the synthesis of prostaglandins (including PGD2).
=== Australian refugee advertisement === In 2002, Nando's ran an advertising campaign in Australia based around a political controversy regarding the mandatory detention of refugees. The detainees had been waging a hunger strike campaign, even resorting to sewing their lips closed. Nando's adverts proclaimed that the strikers "decided to unsew their lips after hearing the news that with every Nando's quarter chicken combo, Nando's are giving away an extra quarter chicken free." Melbourne's Sphere Advertising said that the ad was designed to spark controversy, saying that they knew that "there's a section of our audience that's going to be uncomfortable... but we want to evoke a response."
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.
It is a four-amino-acid peptide with the sequence alanine-glutamate-aspartate-glycine. The chain is unmodified and contains only standard proteinogenic residues, which makes it straightforward to produce by solid-phase synthesis and to characterise by standard peptide methods.