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Thymalin

Also known as Thymus extract, Thymalin peptide bioregulator

Thymalin is a thymic peptide bioregulator developed by Vladimir Khavinson (the same researcher behind Epithalon) from bovine thymus extracts. It has been used in Russian clinical medicine since 1982 for immune system restoration, particularly in immunocompromised patients, the elderly, and post-surgical recovery. Khavinson's long-term studies suggest significant mortality reduction in elderly patients receiving thymalin.

Last updated April 10, 2026

TL;DR

Quick summary

Thymalin is a thymic peptide bioregulator developed by Vladimir Khavinson, used in Russian clinical medicine since 1982 for immune system restoration. Long-term studies suggest significant mortality reduction in elderly patients receiving thymalin combined with epithalon.

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Overview

Thymalin is a thymic peptide bioregulator developed by Vladimir Khavinson (the same researcher behind Epithalon) from bovine thymus extracts. It has been used in Russian clinical medicine since 1982 for immune system restoration, particularly in immunocompromised patients, the elderly, and post-surgical recovery. Khavinson's long-term studies suggest significant mortality reduction in elderly patients receiving thymalin.

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Mechanism of action

Thymalin restores thymic function by modulating T-cell differentiation and maturation. It normalizes the ratio of CD4/CD8 T-cells, enhances natural killer (NK) cell activity, stimulates phagocytosis, and modulates cytokine production. In aging, the thymus involutes (shrinks) dramatically, reducing naive T-cell output — thymalin appears to partially reverse this immunosenescence. It also regulates the neuroendocrine-immune axis.

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Dosing protocols

PurposeRouteDosageFrequency
immune restoration / anti-agingintramuscular510 mgdaily

Dosing information is for educational purposes only. Consult a qualified healthcare professional before using any peptide.

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Research summary

Khavinson's landmark study followed elderly patients for 6-15 years after treatment with thymalin + epithalon. The treatment group showed 1.6-1.8x lower mortality than controls. Thymalin normalized immunological markers, improved cardiovascular function, and reduced cancer incidence. Studies in post-surgical patients showed faster immune recovery and reduced infection rates. Approved in Russia for over 40 years with extensive clinical use. Limitations: most research is in Russian journals with limited Western replication.[1][2][3]

📄This section cites 3 peer-reviewed sources. View all references →
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Evidence grading

Each claimed benefit is graded by the strength of available evidence. Grades reflect study quality, not effect size.

preliminary
Mortality reduction in elderly patientsKhavinson Neuro Endocrinol Lett 2003: 6-15-year follow-up of elderly cohort with thymalin+epithalon; 1.6-1.8x lower mortality; not independently replicated in Western literature
preliminary
T-cell immune restorationRussian clinical use since 1982; normalized CD4/CD8 ratios in immunocompromised patients; limited Western replication
preliminary
Hematopoietic stem cell activationKhavinson Bull Exp Biol Med 2020: in vitro differentiation of human HSCs; mechanistic cell-based evidence
preliminary
Post-surgical infection reductionRussian clinical observational studies in post-surgical patients; faster immune recovery and reduced infection rates; not controlled in Western journals

Strong = multiple RCTs · Moderate = limited trials or observational · Preliminary = animal or in vitro only · Insufficient = anecdotal or no published data

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Side effects

Injection site reactions
Mild allergic reactions (rare)
Low-grade fever (immune activation)

Side effects vary by individual. This is not an exhaustive list. Report unusual symptoms to a healthcare professional.

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Common stacks

Peptides commonly paired with Thymalin for synergistic effects.

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Sourcing & access

Research compound

Thymalin is classified as a research compound. Regulatory status varies by jurisdiction. Always verify current legal status and source from vendors providing third-party certificates of analysis (COA).

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Frequently asked questions

Thymalin is a peptide bioregulator derived from bovine thymus extracts, developed by Vladimir Khavinson. It has been approved and used in Russia since 1982 for immune restoration in immunocompromised patients, the elderly, and post-surgical recovery.

Thymalin restores thymic function by modulating T-cell differentiation and maturation. It normalizes CD4/CD8 T-cell ratios, enhances natural killer cell activity, stimulates phagocytosis, and modulates cytokine production, partially reversing age-related immunosenescence.

Thymalin has over 40 years of clinical use in Russia. Side effects include injection site reactions, mild allergic reactions (rare), and low-grade fever from immune activation. It is not FDA-approved and is available internationally as a research peptide.

Khavinson's landmark study followed elderly patients for 6-15 years. The thymalin plus epithalon treatment group showed 1.6-1.8x lower mortality than controls, with normalized immunological markers and reduced cancer incidence. Most research is in Russian journals with limited Western replication.

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Research references

  1. Peptides of pineal gland and thymus prolong human lifeKhavinson VK, Morozov VGNeuro Endocrinol Lett, 2003PubMed
  2. Geroprotective effect of thymalin and epithalaminKhavinson VK, Bondarev IE, Butyugov AABull Exp Biol Med, 2003PubMed
  3. Thymalin: Activation of Differentiation of Human Hematopoietic Stem CellsKhavinson VK, Linkova NS, Kvetnoy IM, et al.Bull Exp Biol Med, 2020PubMed
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