Epithalon (Epitalon): The Tetrapeptide in the Research Literature

Research-use-only context. This article summarizes published third-party scientific literature and laboratory practice. It is not medical advice, not a therapeutic or performance claim, and not a usage guide. US Prime Peptides products are supplied strictly for in vitro laboratory research and are not for human or veterinary use.

This article surveys the published literature on Epithalon (also spelled Epitalon or Epithalone), the tetrapeptide Ala-Glu-Asp-Gly, sorted by model: the telomerase work in human fibroblasts and its 2025 independent re-examination, DNA- and histone-binding studies, gene-expression profiling, the rodent and Drosophila lifespan and tumor studies, and recent work from laboratories outside Russia. It separates what has been replicated from what has not and states the regulatory position.

Epithalon is Ala-Glu-Asp-Gly, designed from a pineal extract

Epithalon is the synthetic tetrapeptide Ala-Glu-Asp-Gly (one-letter code AEDG), molecular formula C14H22N4O9, molecular weight about 390.4 daltons, PubChem CID 219042, CAS 307297-39-8. Its sequence was not isolated from tissue; it was chosen at the St. Petersburg Institute of Bioregulation and Gerontology to reflect the amino-acid composition of Epithalamin, a bovine pineal polypeptide extract studied in the Soviet Union from the 1970s. A 2025 review in the International Journal of Molecular Sciences by Araj and colleagues at the Medical University of Warsaw makes the point that the two are chemically distinct products that are often conflated, and that physico-chemical and structural studies of the tetrapeptide itself remain scarce despite 25 years of biological papers.

Chemically, Epithalon is small, acidic and very polar: two carboxylate side chains plus the C-terminal carboxylate give it a net negative charge near neutral pH, it has no aromatic or sulfur-containing residue, and it elutes early on reverse-phase HPLC. Purity must be read at 214 or 220 nanometers because the peptide barely absorbs at 280. Like Pinealon, it is typically supplied as a salt whose counter-ion can be a meaningful fraction of vial mass, so the net peptide content line on a certificate matters more than usual (see Net Peptide Content vs Purity). The Epithalon 50 mg listing shows the lot-matched certificate format, with identity by mass spectrometry at the expected protonated mass near 391.2.

Epithalon is not an approved drug in the United States or the European Union. It holds no Russian medicinal registration of the kind Semax and Selank carry; the parent extract Epithalamin was a registered Soviet-era preparation, but the synthetic tetrapeptide has been sold in Russia mainly outside the drug category. A 2026 narrative review by Jain and colleagues notes unresolved regulatory and product-quality questions following a 2026 FDA advisory review of the compound. A research vial is a laboratory chemical documented by its certificate, not by any of the studies below.

Telomerase in human fibroblasts: the original claim and the 2025 re-test

The result that made Epithalon famous is Khavinson, Bondarev and Butyugov (2003, Bulletin of Experimental Biology and Medicine): in telomerase-negative human fetal fibroblast cultures, the peptide was reported to induce expression of the telomerase catalytic subunit, measurable telomerase activity, and telomere elongation. A 2004 follow-up from the same authors reported that primary fetal lung fibroblasts, which stopped dividing at passage 34, made ten additional passages (to 44) after exposure, with telomeres restored to lengths comparable to passage 10. Both papers are short, give limited method detail, and went unreplicated for two decades.

That changed in 2025. Al-Dulaimi, Thomas, Matta and Roberts at Brunel University London (Biogerontology) exposed normal human epithelial cells and fibroblasts, and the breast cancer lines 21NT and BT474, to Epithalon and measured telomere length by qPCR and immunofluorescence, hTERT mRNA, telomerase activity, and markers of the alternative lengthening of telomeres (ALT) pathway. They reported concentration-dependent telomere lengthening in normal cells accompanied by higher hTERT mRNA and telomerase activity, and telomere lengthening in the cancer lines that ran mainly through ALT activation, with only minor ALT activity in normal cells. An erratum to the paper was published in November 2025. This is the first replication of the core telomerase finding by a group unconnected to the St. Petersburg institute, and the first clear report that the peptide can act on cancer-cell telomere maintenance, which complicates the simple "geroprotector" framing.

What the replication does not settle is mechanism. No paper identifies how a 390-dalton acidic tetrapeptide raises hTERT transcription, and no receptor, transporter or promoter-binding event has been demonstrated experimentally.

DNA, histones and gene expression: the proposed mechanism

The Khavinson group's explanation is direct binding to chromatin. Khavinson, Shataeva and Chernova (2005, Neuroendocrinology Letters) proposed from a geometric complementarity model that AEDG could bind the DNA major groove at the sequence ATTTTC, which they noted recurs in the telomerase promoter; the paper is a modeling and statistical argument, not a binding experiment. Fedoreyeva and colleagues (2011, Biochemistry (Moscow)) then reported that fluorescein-labeled Epithalon entered HeLa cell nuclei and nucleoli, and that the unlabeled peptide quenched fluorescence of labeled oligonucleotides in a sequence-dependent way, with preference for CAG- and CNG-containing sequences and sensitivity to cytosine methylation. Khavinson and colleagues (2020, Molecules, with co-authors at the University of Chieti) measured neuronal-differentiation markers in human gingival mesenchymal stem cells and reported 1.6- to 1.8-fold higher Nestin, GAP43, beta-tubulin III and doublecortin mRNA, paired with a docking model predicting AEDG binds histones H1/3 and H1/6 at their DNA-contact sites.

Transcriptome-scale data are older. Anisimov SV and colleagues (2002, Bulletin of Experimental Biology and Medicine) used a 15,247-clone cDNA microarray on mouse heart and reported that Epithalon changed the expression of 98 clones more than two-fold (194 activated and 48 inhibited when combined with Vilon), with maximal changes around six-fold. Ashapkin and colleagues (2020, Molecular Biology Reports) profiled aging human mesenchymal stem cell cultures exposed to short peptides including AEDG. Across all of these, the pattern is the same as for Pinealon: labeled-peptide localization, quenching constants and docking models from one institute, with no chromatin immunoprecipitation, reporter assay or footprint from any group. The mechanism remains a hypothesis.

Lifespan and tumor studies in Drosophila, mice and rats

The longevity literature begins with Khavinson, Izmaylov, Obukhova and Malinin (2000, Mechanisms of Ageing and Development), who added Epithalon to the culture medium of wild-type Canton-S Drosophila only during development and reported 11 to 16 percent longer adult lifespan at extremely low medium concentrations, with no concentration dependence across several orders of magnitude, a feature the authors themselves noted.

The most complete rodent study is Anisimov and colleagues (2003, Biogerontology): 54 female Swiss-derived SHR mice per group from age 3 months until natural death. Epithalon did not change food intake, body weight or mean lifespan. It was associated with a 13.3 percent longer lifespan in the last 10 percent of survivors, a 12.3 percent higher maximum lifespan, 17.1 percent fewer chromosome aberrations in bone-marrow cells, and a slower age-related loss of estrous cycling. Total spontaneous tumor incidence was unchanged, while leukemia incidence was lower. The companion study in FVB/N HER-2/neu transgenic mice (Anisimov 2002, International Journal of Cancer, with Italian co-authors) reported fewer and smaller mammary tumors, smaller lung metastases, and a 3.7-fold lower HER-2/neu mRNA in tumors, while the dipeptide Vilon in the same design produced the opposite, more tumors and shorter latency. Anisimov (2002, Cancer Letters) reported fewer dimethylhydrazine-induced colon tumors in rats, and Vinogradova and colleagues (2007 and 2008, Bulletin of Experimental Biology and Medicine) studied female and male rats under different lighting regimens.

These are real, long-duration animal studies with respectable group sizes, and the Anisimov carcinogenesis work appeared in indexed oncology journals with international co-authors. Their limits are that the same two groups ran all of them, that mean lifespan did not change in the best-powered study, and that no laboratory outside Russia has repeated a lifespan experiment.

Newer work from outside the originating institute

Since 2020 several groups with no St. Petersburg affiliation have published cell-level studies. Yue and colleagues (2022, Aging), at Shanxi Medical University and the Chinese Academy of Sciences, cultured mouse oocytes in vitro with 0.1 millimolar Epithalon and reported lower intracellular reactive oxygen species, fewer spindle defects and cortical-granule abnormalities at 12 and 24 hours of post-ovulatory aging, higher mitochondrial membrane potential and mitochondrial DNA copy number, and less apoptosis at 24 hours. Ullah and colleagues (2025, Life Sciences) reported telomerase-related measurements in bovine oocyte maturation and post-thaw embryo development. Gatta and colleagues (2025, Stem Cell Reviews and Reports, Chieti, with Khavinson as a co-author) exposed the human retinal pigment epithelial line ARPE-19 to high glucose and reported that AEDG restored scratch-wound closure, lowered ROS, and reversed expression of epithelial-mesenchymal transition and fibrosis genes.

What is established, what is not, and what a certificate shows

Established with independent replication: in cultured human cells, Epithalon exposure is associated with higher hTERT mRNA, telomerase activity and telomere length, and in cancer lines with ALT activation. Reported by one or two groups only: lifespan and tumor effects in flies and rodents, DNA and histone binding, and most gene-expression changes. Not established at all: a receptor or transporter, the step that links an acidic tetrapeptide to hTERT transcription, and any controlled human outcome; the 2026 review by Jain and colleagues concludes that human evidence is limited to small physiological or biomarker studies and an older controlled study in retinitis pigmentosa, with pharmacokinetic and long-term safety data inadequate.

For a laboratory buyer, the compound is straightforward to document. Mass spectrometry should show the protonated molecule near 391.2 daltons, HPLC purity should be reported at a short wavelength with the gradient stated, and net peptide content should be given because the counter-ion fraction on a 390-dalton acidic peptide is large. Because the sequence has no oxidizable residue, the main degradation routes are aspartate-related (isomerization and cleavage at Asp-Gly, a known weak point in peptide chemistry) and hydrolysis in solution over time, which argues for storing the lyophilized powder dry and cold, as described in the Peptide Storage and Stability guide. How this tetrapeptide compares with the tripeptide from the same family is covered in Pinealon vs Epithalon.

Frequently Asked Questions

What is Epithalon and where does the sequence come from?

Epithalon is the synthetic tetrapeptide Ala-Glu-Asp-Gly, molecular weight about 390 daltons. The sequence was designed at the St. Petersburg Institute of Bioregulation and Gerontology to mirror the amino-acid composition of Epithalamin, a bovine pineal extract; it was not isolated from tissue.

Has the Epithalon telomerase finding been replicated?

Yes, once. A 2025 Biogerontology paper from Brunel University London reported higher hTERT mRNA, telomerase activity and telomere length in normal human cells, and ALT-driven telomere lengthening in two breast cancer lines. The original 2003 and 2004 reports came from the Khavinson group and had not been independently tested before that.

Is Epithalon an approved drug?

No. Epithalon is not approved by the FDA or any EU regulator and has no Russian medicinal registration of its own; the parent extract Epithalamin was a Soviet-era registered preparation. A 2026 review notes unresolved regulatory questions following a 2026 FDA advisory review. In the US it is a research chemical.

Did Epithalon extend lifespan in mice?

In the 2003 Biogerontology study of 54 female SHR mice per group, mean lifespan did not change. The last 10 percent of survivors lived 13.3 percent longer, maximum lifespan was 12.3 percent higher, and bone-marrow chromosome aberrations were 17.1 percent fewer. No laboratory outside Russia has repeated a lifespan experiment.

Citations

1. Khavinson VKh, Bondarev IE, Butyugov AA. Epithalon peptide induces telomerase activity and telomere elongation in human somatic cells. Bull Exp Biol Med. 2003;135:590-592. PMID 12937682
2. Khavinson VKh, Bondarev IE, Butyugov AA, Smirnova TD. Peptide promotes overcoming of the division limit in human somatic cell. Bull Exp Biol Med. 2004;137:503-506. PMID 15455129
3. Al-Dulaimi S, Thomas R, Matta S, Roberts T. Epitalon increases telomere length in human cell lines through telomerase upregulation or ALT activity. Biogerontology. 2025;26:178. PMID 40908429
4. Khavinson V, Shataeva L, Chernova A. DNA double-helix binds regulatory peptides similarly to transcription factors. Neuro Endocrinol Lett. 2005;26:237-241. PMID 15990728
5. Fedoreyeva LI, Kireev II, Khavinson VKh, Vanyushin BF. Penetration of short fluorescence-labeled peptides into the nucleus in HeLa cells and in vitro specific interaction of the peptides with deoxyribooligonucleotides and DNA. Biochemistry (Mosc). 2011;76:1210-1219. PMID 22117547
6. Khavinson V, Diomede F, Mironova E, et al. AEDG Peptide (Epitalon) Stimulates Gene Expression and Protein Synthesis during Neurogenesis: Possible Epigenetic Mechanism. Molecules. 2020;25:609. PMID 32019204
7. Anisimov SV, Bokheler KR, Khavinson VKh, Anisimov VN. Studies of the effects of Vilon and Epithalon on gene expression in mouse heart using DNA-microarray technology. Bull Exp Biol Med. 2002;133:293-299. PMID 12360356
8. Ashapkin V, et al. Gene expression in human mesenchymal stem cell aging cultures: modulation by short peptides. Mol Biol Rep. 2020;47:4323-4329. PMID 32399807
9. Khavinson VK, Izmaylov DM, Obukhova LK, Malinin VV. Effect of epitalon on the lifespan increase in Drosophila melanogaster. Mech Ageing Dev. 2000;120:141-149. PMID 11087911
10. Anisimov VN, Khavinson VKh, Popovich IG, et al. Effect of Epitalon on biomarkers of aging, life span and spontaneous tumor incidence in female Swiss-derived SHR mice. Biogerontology. 2003;4:193-202. PMID 14501183
11. Anisimov VN, Khavinson VK, Provinciali M, et al. Inhibitory effect of the peptide epitalon on the development of spontaneous mammary tumors in HER-2/neu transgenic mice. Int J Cancer. 2002;101:7-10. PMID 12209581
12. Anisimov VN, et al. Inhibitory effect of peptide Epitalon on colon carcinogenesis induced by 1,2-dimethylhydrazine in rats. Cancer Lett. 2002;183:1-8. PMID 12049808
13. Vinogradova IA, et al. Effect of Ala-Glu-Asp-Gly peptide on life span and development of spontaneous tumors in female rats exposed to different illumination regimes. Bull Exp Biol Med. 2007;144:825-830. PMID 18856211
14. Yue X, Liu SL, Guo JN, et al. Epitalon protects against post-ovulatory aging-related damage of mouse oocytes in vitro. Aging (Albany NY). 2022;14:3191-3202. PMID 35413689
15. Ullah S, et al. Epitalon-activated telomerase enhance bovine oocyte maturation rate and post-thawed embryo development. Life Sci. 2025;362:123381. PMID 39788414
16. Gatta M, Dovizio M, Milillo C, et al. The Antioxidant Tetrapeptide Epitalon Enhances Delayed Wound Healing in an in Vitro Model of Diabetic Retinopathy. Stem Cell Rev Rep. 2025;21:1822-1834. PMID 40493162
17. Araj SK, Brzezik J, Madra-Gackowska K, Szeleszczuk L. Overview of Epitalon-Highly Bioactive Pineal Tetrapeptide with Promising Properties. Int J Mol Sci. 2025;26:2691. PMID 40141333
18. Jain A, Gallacher DM, Issa MA, et al. Epitalon and Epithalamin: A Narrative Review of Mechanistic, Preclinical, and Clinical Evidence. Int J Mol Sci. 2026;27:8922. PMID 42884164

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