the spelling with an h
Epithalon (Epitalon): The Pineal Tetrapeptide in the Research Literature
Two spellings, one molecule — the AEDG tetrapeptide of the Khavinson St. Petersburg program, read against twenty-five years of peer-reviewed work.
Epitalon vs Epithalon: same molecule, two spellings
Epithalon and Epitalon are the same tetrapeptide — Ala-Glu-Asp-Gly (AEDG), molecular formula C14H22N4O9, molar mass 390.35 g/mol [15]. 'Epithalon' is the more common transliteration from the Russian literature and is the spelling preferred by most peptide databases and search-engine query volume. 'Epitalon' is the simplified English form, the spelling used by Wikipedia, and the form embedded in this domain. Both spellings appear in the PubMed record, sometimes within the same paper title — the seminal 2003 paper from Khavinson, Bondarev and Butyugov is indexed as 'Epithalon peptide induces telomerase activity and telomere elongation in human somatic cells' [1], while the 2002 mammary-tumor paper from Anisimov and colleagues is indexed as 'Inhibitory effect of the peptide epitalon...' [4]. The same molecule, the same lab, two spellings of the same Russian noun.
Spelling variants: Epitalon, Epithalon, Epithalone
All three are spellings of the same AEDG tetrapeptide. 'Epithalon' and 'Epithalone' are transliterations from Cyrillic; 'Epitalon' is the simplified English form Wikipedia uses [15]. 'Epithalone' (with a terminal 'e') turns up in older Russian-program review articles. None of the spellings denote a different molecule, dose, or formulation — they denote the same defined-sequence synthetic tetrapeptide that the Khavinson program has worked with since the 1980s [14].
Why the spelling discrepancy persists
Russian-to-English transliteration of biomedical terminology is unstandardised. The Russian noun for the molecule contains a Cyrillic 'th' analog that some translators render as 'th' and others elide to 't'. PubMed's controlled vocabulary does not collapse the variants, so a thorough literature search has to query both spellings — and at least one Khavinson-group paper in Bulletin of Experimental Biology and Medicine uses both spellings in the same article [1]. Modern Western papers (Al-dulaimi 2025, Araj 2025) standardise on 'Epitalon' in the abstract and title but acknowledge 'Epithalon' as the prior literature's preferred form [2][15].
Why this matters for reading the literature
Anyone trying to read the Epitalon record seriously has to search both spellings. A PubMed query for 'Epitalon' returns roughly the modern Western-indexed papers and the Anisimov 2002 series; a query for 'Epithalon' returns the Khavinson 2003 seminal telomerase paper, the Korkushko 2004 elderly-melatonin cohort, and several of the Russian-language review articles indexed in English [1][11]. Missing either spelling produces a partial reading. This site uses 'Epitalon' as the canonical site spelling (matching the domain) and 'Epithalon' as the recurring co-mention, because both spellings appear in the publication record and conflating them obscures the literature's geography.
What the 'Epithalon' spelling tends to mark
In the peer-reviewed record, the 'Epithalon' spelling clusters with the Russian-program work — the Khavinson 2003 telomerase paper [1], the Korkushko 2004 elderly-cohort melatonin paper [11], the 2007 illumination-regime rat-lifespan paper [10], and the Khavinson 2002 retinitis pigmentosa series [13]. The 'Epitalon' spelling clusters with the Anisimov-led cancer-model series in International Journal of Cancer and Cancer Letters [4][8] and with the 2025 Western replications [2][15]. Functionally there is no molecular distinction — the spelling cue is a publication-venue cue, not a chemistry cue.
How the spelling affects search and citation
DataForSEO returns roughly 8,100 monthly queries for 'Epithalon' and a markedly smaller volume for 'Epitalon' — the spelling with an h carries the dominant consumer search intent. PubMed, in contrast, indexes both spellings with the variant preserved exactly as the author submitted. For literature work, query both spellings. For consumer-facing reading, the 'Epithalon' spelling will surface most non-academic results. Citation practice on this site preserves the spelling each author used in the original title — a small editorial fidelity that helps a reader trace papers back to their indexed forms.
Reading both spellings forward
The rest of this dossier uses 'Epitalon' for site-prose continuity and 'Epithalon' where the cited paper uses that spelling — which means both appear throughout the research page, the dosage page, and the frequently asked questions. When the AEDG peptide is named in a paper title, this site preserves the title's spelling without normalisation. The molecule is one. The vocabulary, for historical and translational reasons, is two.