Head to head
Epitalon against Thymalin
The two Khavinson peptides with the largest claimed human records, pineal and thymic. Both have long Russian cohort literatures reporting mortality differences, none of it blinded, and none of it replicated outside that research tradition.
Column A
EpitalonEpitalon (Epithalon, pineal tetrapeptide)
A synthetic pineal tetrapeptide with more human data than its reputation suggests, including a 6 to 8 year observation of 266 elderly people and a 12 to 15 year randomized comparison in coronary patients. Almost all of it comes from one research lineage, and none of it was blinded.
Column B
ThymalinThymalin (thymic peptide bioregulator)
A calf-thymus peptide preparation used clinically in the Soviet Union and Russia since the 1980s, with a large Russian clinical literature, a 6 to 8 year cohort reporting roughly twofold lower mortality, and a 92-patient open-label randomized COVID-19 trial. None of it has been replicated outside that tradition.
Side by side, on the facts we can check
| Attribute | Epitalon | Thymalin |
|---|---|---|
| Category | Anti-aging | Immune |
| FDA status | Not FDA-approved. PCAC voted 7 to 4 (1 abstention) to recommend for compounding for insomnia (July 24, 2026); awaiting FDA rulemaking | Not FDA-approved. Not among the seven peptides reviewed by the FDA Pharmacy Compounding Advisory Committee in July 2026 |
| Half-life | Short (minutes) | Short |
| Molecular weight | 390.3 Da | Mixture of thymic polypeptides, so no single molecular weight; the manufacturer describes a low-kilodalton fraction |
| Mechanism | Epitalon is proposed to act as a gene-regulating signal rather than a receptor ligand. In telomerase-negative human fetal fibroblasts it induced expression of the telomerase catalytic subunit, telomerase activity and telomere elongation, and treated cultures ran to passage 44 against 34 in controls, about ten extra population doublings. A 2025 study from an unrelated laboratory reported the same direction of effect, dose-dependent telomere lengthening through hTERT expression and telomerase activity in normal human cells, with a separate alternative-lengthening pathway seen only in cancer lines. In people the most consistently reported effect is on melatonin: a course of the parent pineal preparation raised night-time melatonin in elderly subjects whose pineal output was low and tended to lower it in those whose output was normal. The step that would connect the two, a four amino acid peptide entering the nucleus and interacting directly with DNA, has been reported only by the originating group and is not settled. | Thymalin supplies a mixture of thymic signalling peptides intended to substitute for the falling output of the involuting thymus. In cultured human hematopoietic stem cells it reduced the stem marker CD44 and the intermediate marker CD117 2 to 3-fold and raised CD28, a marker of mature T lymphocytes, 6.8-fold, which the authors read as a push toward mature T-cell differentiation. Two dipeptides are proposed as its active components: Lys-Glu, reported to activate macrophages, lymphocytes, thymocytes and neutrophils, and Glu-Trp, which was isolated from Thymalin by reversed-phase HPLC in the 1990s and developed separately as the drug Thymogen. Because Thymalin is an extract rather than a defined molecule, batch composition is not fixed, and no single molecular weight or potency unit describes it. |
| Human studies cited | 6 | 4 |
| Legal status, US | Not approved; research use only | Not approved; research use only |
Frequently asked questions
What is the difference between Epitalon and Thymalin?
Epitalon: A synthetic pineal tetrapeptide with more human data than its reputation suggests, including a 6 to 8 year observation of 266 elderly people and a 12 to 15 year randomized comparison in coronary patients. Almost all of it comes from one research lineage, and none of it was blinded. Thymalin: A calf-thymus peptide preparation used clinically in the Soviet Union and Russia since the 1980s, with a large Russian clinical literature, a 6 to 8 year cohort reporting roughly twofold lower mortality, and a 92-patient open-label randomized COVID-19 trial. None of it has been replicated outside that tradition.
Which has stronger research evidence, Epitalon or Thymalin?
This database does not grade compounds. It counts what was run in people: 6 of the 13 studies cited on the Epitalon profile were human work, against 4 of 8 for Thymalin. Those counts are of our own citation lists and understate any larger literature, and neither is a recommendation.
Are Epitalon and Thymalin FDA-approved?
Epitalon: Not FDA-approved. PCAC voted 7 to 4 (1 abstention) to recommend for compounding for insomnia (July 24, 2026); awaiting FDA rulemaking. Thymalin: Not FDA-approved. Not among the seven peptides reviewed by the FDA Pharmacy Compounding Advisory Committee in July 2026.
Related posts
Blog articles that cover Epitalon or Thymalin, newest first.
- Longevity / Sep 8, 2026 / 12 minPeptides for Longevity: What the Evidence Actually Shows in 2026
- Research / Sep 8, 2026 / 9 minPeptides for Sleep: DSIP, Epitalon and Pinealon Against the Evidence
- Regulation / Sep 8, 2026 / 9 minFDA Peptide Status in 2026: The Category 2 Removals, the July Votes, and What Actually Changed
Reviewed Sep 2026. This page sets two published records side by side. It is educational, it is not medical advice, and it contains no dosing protocols or recommendations for personal use.