Supplement analysis backed by scientific evidence · PT

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Limited evidenceImmunity

Transfer Factor

Colostrum-derived products sold as immune messengers, borrowing the name of a 1950s immunological concept. The original research concerned injected leukocyte extracts in specific immunodeficiencies, not capsules from cow colostrum.

Evidence last reviewed: August 2026

What the science says

  • The commercial product is not the studied substance Limited evidence

    A review examining the myths and facts around transfer factor concluded that the active molecules were never properly characterised and that modern commercial preparations lack controlled evidence for the general immune benefits claimed on their labels.

  • Historical clinical use was narrow and specialised Limited evidence

    Reviews of dialyzable leukocyte extracts describe use in specific conditions such as chronic mucocutaneous candidiasis and certain immunodeficiencies, given by injection under medical supervision. That literature does not support an oral colostrum supplement for everyday immunity.

  • No trials in healthy adults Limited evidence

    There is no randomized controlled trial showing that oral transfer factor supplements reduce the frequency or duration of common infections in healthy people.

Dosage & safety

Studied doseNo established dose. Labels typically suggest 200–600 mg of colostrum-derived powder daily.
SafetyDairy-derived, so unsuitable for people with milk allergy and possibly for those with severe lactose intolerance depending on processing. Composition varies unpredictably between brands. Avoid in autoimmune disease and during immunosuppressive therapy without medical advice; no data in pregnancy.

Scientific references

Where to buy

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