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Limited evidenceImmunity

Thymus Extract

A bovine glandular product based on the idea that thymus peptides can prime the immune system. The supporting trials are Italian paediatric studies from the 1980s and 1990s; nothing modern replaces them.

Where to buy

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What the science says

  • Old paediatric trials of thymomodulin Limited evidence

    A randomized trial in children with recurrent respiratory infections reported a preventive effect of thymomodulin, a calf thymus derivative. These studies are more than three decades old, small, single-country, and reported in ways that would not meet current standards.

  • Modern reviews cover different products Limited evidence

    A Cochrane review of immunostimulants for preventing exacerbations in chronic bronchitis and COPD found possible reductions in exacerbations but rated the evidence low quality, and the agents assessed are pharmaceutical bacterial lysates rather than over-the-counter bovine thymus supplements.

  • Oral peptides face a basic obstacle Limited evidence

    Thymic peptides are proteins, and swallowed proteins are digested. No trial has demonstrated that intact bioactive thymic peptides reach the circulation from an oral supplement.

Dosage & safety

Studied doseNo established dose. Labels commonly suggest 500 mg of bovine thymus tissue or concentrate daily.
SafetyBovine glandular tissue carries a theoretical risk of transmissible spongiform encephalopathy, so country of origin and sourcing controls matter. Products are not standardised and composition varies between brands. Avoid in autoimmune disease, during immunosuppressive therapy, after transplantation, and in pregnancy.

How to take it

TimingTiming does not matter.
With food?Either way.
Worth knowingAsk the brand for the country of origin of the bovine tissue and its BSE controls — that, not the dose, is the question worth asking here.

Interactions

With medications

  • immunosuppressants, transplant medication and biologics for autoimmune disease

    Sold as an immune stimulant, so it may directly oppose therapy intended to suppress immunity. do not use it after transplantation or during immunosuppressive treatment

Well-established interactions only — this is not a complete list. Always tell your doctor and pharmacist what you take.

Frequently asked questions

Does thymus extract boost the immune system?

The evidence for thymus extract is limited: the supporting trials are small Italian paediatric studies of thymomodulin from the 1980s and 1990s. No trial shows that thymic peptides from an oral supplement reach the circulation intact, since swallowed proteins are digested.

Is bovine thymus extract safe?

Bovine thymus extract carries a theoretical risk of transmissible spongiform encephalopathy, so ask for the country of origin and BSE controls. Products are not standardised, and thymus extract should be avoided in autoimmune disease, after transplantation and in pregnancy.

Can I take thymus extract with immunosuppressants?

No. Thymus extract is sold as an immune stimulant and may directly oppose immunosuppressants, transplant medication or biologics for autoimmune disease, so do not use it during that treatment.

Scientific references

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