Pineal peptide is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2026-07-09. Where a claim depends on a specific study, the study is described rather than over-claimed.
Identity and purity are checked by reversed-phase high-performance liquid chromatography, usually with ultraviolet detection near 214 nanometres, where the peptide bond absorbs. Mass spectrometry confirms the expected mass and reveals whether truncation products or adducts are present. Acid hydrolysis followed by amino acid analysis gives the residue ratio, which should approximate one alanine, one glutamate, one aspartate and one glycine. Counter-ions such as acetate or trifluoroacetate remain in the dried product and lower net peptide content, so a stated purity figure on a label does not by itself describe how much peptide a vial holds.
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.
In its supplied form epitalon is a white to off-white powder, usually lyophilized and often hygroscopic. It dissolves readily in water and in aqueous buffers, and it is commonly handled as the acetate or trifluoroacetate salt to improve stability during purification and drying. The amide backbone is labile in aqueous media, so solutions are less durable than the dry solid. Handling notes in the chemical literature therefore emphasize keeping the powder dry, cool and shielded from light until it is dissolved.
Epitalon is a synthetic tetrapeptide whose sequence is alanine-glutamate-aspartate-glycine, written in single-letter code as AEDG. The four residues are joined by three peptide bonds, giving a linear backbone with no branching and no disulfide bridges. Its calculated molecular mass for the free form is approximately 390.3 daltons, a figure that rises when the compound is supplied as an acetate or trifluoroacetate salt. Because the chain is short, the molecule is defined entirely by its residue order rather than by any folded three-dimensional structure.
| 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 |
Purity assessment of peptide reagents normally relies on reversed-phase high-performance liquid chromatography. A gradient of acetonitrile in water with trifluoroacetic acid, paired with a C18 stationary phase, separates the target tetrapeptide from truncated sequences and deletion analogues. Detection at 214 nanometres exploits absorbance of the peptide backbone, since the molecule contains no aromatic residue. Results are expressed as a percentage of total peak area. Values above ninety-five percent are typical for research-grade material, although reporting conventions vary between suppliers.
Identity confirmation uses mass spectrometry, usually electrospray ionisation in positive mode or matrix-assisted laser desorption. The protonated free peptide produces a signal near three hundred and ninety-one daltons, while salt adducts shift that value slightly. Tandem mass spectrometry or amino acid analysis supplies sequence-level confirmation, which a single mass measurement cannot. Peptides containing aspartate can cyclise into succinimide intermediates that hydrolyse to isoaspartate isomers of identical mass. Because those isomers are difficult to separate chromatographically, identity and purity results carry more weight when interpreted together.
Several names circulate for the same molecule, including epitalon, epithalone, epithalamin tetrapeptide, and the sequence code AEDG. A CAS registry number, 307297-39-8, is commonly cited for it, though catalogue entries should be checked against supplier documentation because mislabelled records occur. In its usual form the peptide carries free amino and carboxyl termini and is neither glycosylated nor lipidated. Researchers distinguish the defined tetrapeptide from epithalamin itself, a crude pineal preparation containing many peptides that is not chemically characterised.
Material supplied for laboratory use is normally a lyophilised white to off-white powder that dissolves readily in water and in isotonic saline. Lyophilised cakes are hygroscopic and should be equilibrated to room temperature before opening to limit condensation on the solid. Solutions are typically prepared at milligram-per-millilitre concentrations and divided into single-use aliquots, because repeated freeze–thaw cycles degrade short peptides. Aqueous solutions are far less stable than the dry powder, and identity is usually verified by mass spectrometry alongside purity estimation from reversed-phase high-performance liquid chromatography.
Epitalon is a synthetic linear tetrapeptide with the sequence alanine–glutamate–aspartate–glycine, abbreviated AEDG. Its molecular formula is C14H22N4O9 and the calculated mass is approximately 390.35 g/mol. The compound is made by solid-phase peptide synthesis rather than extracted from tissue, although early work described it as a short fragment of a peptide fraction obtained from bovine pineal extract. In the research literature the spelling epitalon and the variant epithalone both appear, while AEDG is the standard code used in peptide nomenclature.
Identity is normally established by reversed-phase high-performance liquid chromatography combined with mass spectrometry, a pairing that separates components and confirms molecular mass at once. Purity is quoted as a percentage from the chromatogram, and figures above ninety-five percent are a frequent commercial specification. Amino acid analysis or sequencing supplies further confirmation when required. Because many short peptides behave similarly under chromatography, retention time alone does not establish sequence; the mass measurement is what separates one tetrapeptide from another, and certificates should report both.
Short peptides such as AEDG are normally supplied as a freeze-dried solid and are kept dry, cold, and shielded from light. Holding at minus twenty degrees Celsius is common for the long term, while a refrigerator suffices for brief periods before use. The material takes up moisture to some degree, so containers should stay sealed and be allowed to reach room temperature before opening, which limits condensation on the contents. Repeated warming and cooling of a single container is discouraged because it admits water and can lower the amount of intact peptide.
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.
1993/2131) Courts and Legal Services Act 1990 (Commencement No. 9) Order 1993 (S.I. 1993/2132) Rules of the Supreme Court (Amendment) 1993 (S.I. 1993/2133) Leasehold Reform, Housing and Urban Development Act 1993 (Commencement and Transitional Provisions No. 1) Order 1993 (S.I. 1993/2134) Edinburgh Assay Office (Amendment) Order 1993 (S.I. 1993/2135) County Court (Amendment No. 2) Rules 1993 (S.I. 1993/2150) Combined Probation Areas (Hertfordshire) Order 1993 (S.I. 1993/2151) Manchester, Liverpool Road (Castlefield Properties Limited) Light Railway Order 1993 (S.I. 1993/2153) East Kent Light Railway Order 1993 (S.I. 1993/2154) Mental Health (Nurses) Amendment Order 1993 (S.I. 1993/2155) Mental Health (Hospital, Guardianship and Consent to Treatment) Amendment Regulations 1993 (S.I. 1993/2156) Leasehold Reform, Housing and Urban Development Act 1993 (Commencement No. 2) (Scotland) Order 1993 (S.I. 1993/2163) Housing (Preservation of Right to Buy) (Scotland) Regulations 1993 (S.I. 1993/2164) Employment Protection (Continuity of Employment) Regulations 1993 (S.I. 1993/2165) Controlled Drugs (Substances Useful for Manufacture) (Intra–Community Trade) Regulations 1993 (S.I. 1993/2166) Tobacco Products (Amendment) Regulations 1993 (S.I. 1993/2167) A45/A452 Trunk Roads (Stonebridge Grade Separation) Order 1993 (S.I. 1993/2168) Education (Further Education Institutions Information) (Wales) Regulations 1993 (S.I. 1993/2169) A45 Trunk Road (Middle Bickenhill to Stonebridge) (De-Trunking) Order 1993 (S.I.
== External links == WHO Snake Antivenoms Database Organization (2016). Guidelines for the management of snakebites. Regional Office for South-East Asia, World Health Organization. hdl:10665/249547. ISBN 978-92-9022-530-0.
== International law == Trump's proposal for Gaza is against international law; the forcible transfer of populations is prohibited. Members of Trump's administration have walked back on elements of the plan on a few occasions, although in one subsequent statement, Trump held firm to his original plan. On 21 February 2025, after opposition from Arab states, Trump said he would "recommend" but not enforce his plan for the American takeover of Gaza and the re-settlement of the Palestinian population. Arab League leaders met in March to create a counter proposal to Trump's plan, which was rejected by the US and Israel due to concerns about the proposed governance of postwar Gaza and other issues. The White House released a statement that Trump stood by his vision of Gaza without Hamas and welcomed additional talks. In July, Netanyahu met with Trump and reiterated support for the plan of relocating Palestinians, saying it was "free choice" if Palestinians wanted to stay or leave. The US and Israel were working to identify cooperating countries for the plan.
==== Dietary recommendations ==== The U.S. Institute of Medicine (IOM) updated Estimated Average Requirements (EARs) and Recommended Dietary Allowances (RDAs) for iron in 2001. The current EAR for iron for women ages 14–18 is 7.9 mg/day, 8.1 mg/day for ages 19–50 and 5.0 mg/day thereafter (postmenopause). For men, the EAR is 6.0 mg/day for ages 19 and up. The RDA is 15.0 mg/day for women ages 15–18, 18.0 mg/day for ages 19–50 and 8.0 mg/day thereafter. For men, 8.0 mg/day for ages 19 and up. RDAs are higher than EARs so as to identify amounts that will cover people with higher-than-average requirements. RDA for pregnancy is 27 mg/day and, for lactation, 9 mg/day. For children ages 1–3 years 7 mg/day, 10 mg/day for ages 4–8 and 8 mg/day for ages 9–13. As for safety, the IOM also sets Tolerable upper intake levels (ULs) for vitamins and minerals when evidence is sufficient. In the case of iron, the UL is set at 45 mg/day. Collectively the EARs, RDAs and ULs are referred to as Dietary Reference Intakes. 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 the PRI is 13 mg/day ages 15–17 years, 16 mg/day for women ages 18 and up who are premenopausal and 11 mg/day postmenopausal. For pregnancy and lactation, 16 mg/day. For men the PRI is 11 mg/day ages 15 and older. For children ages 1 to 14, the PRI increases from 7 to 11 mg/day.
== In blood == Triglycerides are transported through the blood to appropriate tissues (adipose, muscle, etc.) by lipoproteins such as Very-Low-Density-Lipoproteins (VLDL). Triglycerides present on the VLDL undergo lipolysis by the cellular lipases of target tissues, which yields glycerol and free fatty acids. Free fatty acids released into the blood are then available for cellular uptake. Free fatty acids not immediately taken up by cells may bind to albumin for transport to surrounding tissues that require energy. Serum albumin is the major carrier of free fatty acids in the blood. The glycerol also enters the bloodstream and is absorbed by the liver or kidney where it is converted to glycerol 3-phosphate by the enzyme glycerol kinase. Hepatic glycerol 3-phosphate is converted mostly into dihydroxyacetonephosphate (DHAP) and then glyceraldehyde 3-phosphate (GA3P) to rejoin the glycolysis and gluconeogenesis pathway.
Sources: en.wikipedia.org
Malaysia has a multi-ethnic, multicultural, and multilingual society. Substantial influence exists from Chinese and Indian cultures, dating back to when foreign trade began. Other cultural influences include the Persian, Arabic, and British cultures. Due to the structure of the government, coupled with the social contract theory, there has been minimal cultural assimilation of ethnic minorities. Some cultural disputes exist between Malaysia and neighbouring countries, notably Indonesia. In 1971, the government created a "National Cultural Policy", defining Malaysian culture. It stated that Malaysian culture must be based on the culture of the indigenous peoples of Malaysia, that it may incorporate suitable elements from other cultures, and that Islam must play a part in it. It also promoted the Malay language above others. This government intervention into culture has caused resentment among non-Malays who feel their cultural freedom was lessened. Both Chinese and Indian associations have submitted memorandums to the government, accusing it of formulating an undemocratic culture policy.
In November 1997 National Theatre of Greece launched a worldwide tour of Medea, a critically acclaimed production directed by Nikaiti Kontouri, starring Karyofyllia Karambeti as Medea, Kostas Triantafyllopoulos as Creon and Lazaros Georgakopoulos as Jason. The tour included performances in France, Australia, Israel, Portugal, United States, Canada, Turkey, Bulgaria, China and Japan and lasted almost two years, until July 1999. The play opened in the United States at Shubert Theatre in Boston (18 and 19 September 1998) and then continued at City Center Theatre in Manhattan, New York City (23 to 27 September 1998), receiving a very positive review from The New York Times. Neil LaBute wrote Medea Redux, a modern retelling, first performed in 1999 starring Calista Flockhart, as part of his one-act trilogy entitled Bash: Latter-Day Plays. In this version, the main character is seduced by her middle-school teacher. He abandons her, and she kills their child out of revenge. Michael John LaChiusa created a Broadway musical adaptation work for Audra McDonald entitled Marie Christine in 1999. McDonald portrayed the title role, and the show was set in 1890s New Orleans and Chicago. Liz Lochhead's Medea previewed at the Old Fruitmarket, Glasgow as part of Theatre Babel's Greeks in 2000 before the Edinburgh Fringe and national tour. "What Lochhead does is to recast MEDEA as an episode-ancient but new, cosmic yet agonisingly familiar- in a sex war which is recognisable to every woman, and most of the men, in the theatre", wrote The Scotsman.
=== Social sciences === Finance: a retirement fund will decay exponentially being subject to discrete payout amounts, usually monthly, and an input subject to a continuous interest rate. A differential equation dA/dt = input − output can be written and solved to find the time to reach any amount A, remaining in the fund. In simple glottochronology, the (debatable) assumption of a constant decay rate in languages allows one to estimate the age of single languages. (To compute the time of split between two languages requires additional assumptions, independent of exponential decay).
=== Visual and other effects of hormonal changes === Testosterone will cause an enlargement of the clitoris and possibly has important effects on the growth and maturation of the vestibular bulbs, corpora cavernosa of the clitoris and urethral sponge. Changes of the vulva initiated by estradiol as well as its direct effects also appear to influence the functioning of the lower urinary tract.
Temperature in the anus (rectum/rectal) is at or over 37.5–38.3 °C (99.5–100.9 °F). An ear (tympanic) or forehead (temporal) temperature may also be used. Temperature in the mouth (oral) is at or over 37.2 °C (99.0 °F) in the morning or over 37.7 °C (99.9 °F) in the afternoon Temperature under the arm (axillary) is usually about 0.6 °C (1.1 °F) below core body temperature. In adults, the normal range of temperatures in healthy individuals is 36.32–37.76 °C (97.4–100.0 °F) (rectal), 35.76–37.52 °C (96.4–99.5 °F) (ear), 35.61–37.61 °C (96.1–99.7 °F) (urine), 35.73–37.41 °C (96.3–99.3 °F) (oral), and 35.01–36.93 °C (95.0–98.5 °F) (axillary), with no significant gender differences. Normal body temperatures vary depending on many factors, including age, sex, time of day, ambient temperature, activity level, and more. Normal daily temperature variation has been described as 0.5 °C (0.9 °F). A raised temperature is not always a fever. For example, the temperature rises in healthy people when they exercise, but this is not considered a fever, as the set point is normal. On the other hand, a "normal" temperature may be a fever, if it is unusually high for that person; for example, medically frail elderly people have a decreased ability to generate body heat, so a "normal" temperature of 37.3 °C (99.1 °F) may represent a clinically significant fever.
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.
The peptide contains four residues in the order alanine, glutamate, aspartate and glycine, abbreviated AEDG. The chain is linear and held together by three peptide bonds. Its calculated mass for the uncharged free form is about 390.3 daltons.