Is Vitamin E (High-dose) Safe with Tamoxifen?
Free · No account · based on published sources including NIH ODS, FDA drug labels, and peer-reviewed literature
Avoid high-dose vitamin E supplements (>400 IU/day) during tamoxifen therapy. Discuss any antioxidant supplement use with your oncologist before starting.
Why this interaction occurs
High-dose antioxidants including vitamin E may interfere with tamoxifen-induced oxidative stress mechanisms that contribute to its apoptotic effects in hormone receptor-positive breast cancer cells, potentially reducing efficacy.
Evidence
Evidence level: moderate.
Reported safety data
The FDA’s adverse event reporting system (FAERS) has received 22,724 reports mentioning Tamoxifen. This reflects reported cases involving the medication in general — not confirmed causation, and not specific to the Tamoxifen + supplement combination on this page.
FAERS reports are voluntary and cannot prove that a drug caused an event. Do not use report counts to assess the safety of this specific drug-supplement pair.
Frequently asked questions
Related interactions
All Vitamin E (High-dose) interactions → · All Tamoxifen interactions →
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Educational only — not medical advice.
Always confirm with your doctor or pharmacist.