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Comparison

Epitalon vs Thymalin

Epitalon is bioregulators; Thymalin is thymic & immune. They are compared here because they are frequently considered against each other, not because they act alike.

Epitalon Thymalin
Class Bioregulators Thymic & immune
Evidence Preliminary human Preliminary human
Human trials ~2 ~5
Half-life Not established Not established
Reported range 100-200 mcg 10-20 mg
Frequency Once daily for 10-20 day courses, 2-3 courses per year Once daily for 5-10 days
Routes Subcutaneous, Oral, Intramuscular Intramuscular, Subcutaneous
FDA approved No No
Research use only Yes Yes
Banned in sport No No
Studied for Longevity research, Melatonin rhythm, Telomere research Immune restoration research, Geriatric immunity research
Reported side effects Injection-site reactions, Transient fatigue Injection-site reactions, Transient fatigue

Epitalon

Epitalon is one of the short peptide bioregulators characterised by Vladimir Khavinson, a series of di- to tetrapeptides each associated with a specific tissue. The proposed mechanism is direct interaction with DNA promoter regions to modulate transcription of tissue-specific genes, restoring protein synthesis in ageing or damaged tissue. It is the most studied compound in the series, associated in the original work with restoration of melatonin rhythm and with telomerase activation in cell culture. Nearly all supporting work comes from a single research group and has not been independently replicated under contemporary trial standards, which is the central limitation of the entire class and should be stated on every page in it.

Thymalin

Thymalin is a mixture of polypeptide fractions isolated from bovine thymus rather than a single defined molecule, which is an important distinction from thymosin alpha-1. It is reported to restore T-lymphocyte differentiation and normalise immune indices in immunodeficiency states. The frequently cited evidence is a long-running Russian geriatric cohort reporting reduced mortality; that work has not been replicated under contemporary trial standards.

Epitalon vs Thymalin: common questions

What is the difference between Epitalon and Thymalin?

Epitalon is bioregulators and Thymalin is thymic & immune, so they act on different pathways. Epitalon: A short peptide bioregulator directed at the pineal gland, from the Khavinson series developed at the St. Petersburg Institute of Bioregulation and Gerontology. Thymalin: A polypeptide fraction extracted from calf thymus, used clinically in Russia and studied in long-term geriatric cohorts.

Which has stronger evidence, Epitalon or Thymalin?

They sit at the same evidence level: preliminary human. Epitalon has about 2 human studies and Thymalin about 5.

Are Epitalon and Thymalin FDA approved?

Neither is FDA approved for any indication.

References

Regulatory and primary sources

  1. PubChem compound record (CID 219042) ↗ · structure, identifiers, synonyms
  2. FDA: Unapproved drugs and "research use only" products ↗ · regulatory status of non-approved products
  3. PubChem compound record (CID 3085284) ↗ · structure, identifiers, synonyms

Published literature

  1. Khavinson VKh. Peptides and Ageing.Neuro Endocrinol Lett 2002.PubMed 12374906
  2. Rahman OF, Lee SJ, Seeds WA. Therapeutic Peptides in Orthopaedics: Applications, Challenges, and Future Directions.J Am Acad Orthop Surg Glob Res Rev 2026.PubMed 41490200 · doi:10.5435/JAAOSGlobal-D-25-00236
  3. Araj SK, Brzezik J, Mądra-Gackowska K, et al.. Overview of Epitalon-Highly Bioactive Pineal Tetrapeptide with Promising Properties.Int J Mol Sci 2025.PubMed 40141333 · doi:10.3390/ijms26062691
  4. Khavinson V, Linkova N, Diatlova A, et al.. Peptide Regulation of Cell Differentiation.Stem Cell Rev Rep 2020.PubMed 31808038 · doi:10.1007/s12015-019-09938-8
  5. Khavinson V, Linkova N, Dyatlova A, et al.. Peptides: Prospects for Use in the Treatment of COVID-19.Molecules 2020.PubMed 32987757 · doi:10.3390/molecules25194389
  6. Ivko OM, Trofimova SV, Trofimov AV, et al.. [Peptidergic regulation of expression of cellular aging marker proteins in buccal epithelium.].Adv Gerontol 2024.PubMed 39742404
  7. Kloeden PE, Rössler R, Rössler OE. Artificial life extension. The epigenetic approach.Ann N Y Acad Sci 1994.PubMed 8010616 · doi:10.1111/j.1749-6632.1994.tb56852.x
  8. Anisimov VN, Arutjunyan AV, Khavinson VK. Effects of pineal peptide preparation Epithalamin on free-radical processes in humans and animals.Neuro Endocrinol Lett 2001.PubMed 11335874
  9. Khavinson VKh, Morozov VG. [Geroprotective effect of thymalin and epithalamin].Adv Gerontol 2002.PubMed 12577695
  10. Litvinenko GI, Shurlygina AV, Dergacheva TI, et al.. Chrono- and Immunocorrection of Inflammatory Disorders of Internal Reproductive Organs in Women of Reproductive Age.Bull Exp Biol Med 2015.PubMed 26033592 · doi:10.1007/s10517-015-2890-0
  11. Khavinson VKh, Morozov VG. Peptides of pineal gland and thymus prolong human life.Neuro Endocrinol Lett 2003.PubMed 14523363
  12. Lin'kova NS, Poliakova VO, Kvetnoĭ IM, et al.. [Characteristics of the pineal gland and thymus relationship in aging].Adv Gerontol 2011.PubMed 21809618
  13. Lin'kova NS, Poliakova VO, Trofimov AV, et al.. [Influence of peptides from pineal gland on thymus function at aging].Adv Gerontol 2010.PubMed 21510076
  14. Musienko GV. [Thymalin in the combined treatment of parkinsonism patients].Lik Sprava 1999.PubMed 10424021
  15. Domina EA. Chornobyl catastrophe: cytogenetic effects of low dose ionizing radiation and their modification.Exp Oncol 2016.PubMed 28230819

Literature retrieved from PubMed on October 16, 2026, favouring human studies and reviews. Numbered markers in the text show which paper supports which statement; uncited entries are background reading.

Read this first This page compares published reference data. It is not medical advice and not a recommendation to use either compound. Several compounds documented on this site are not approved for human use.