Is Folic Acid Safe with Capecitabine?
Free · No account · based on published sources including NIH ODS, FDA drug labels, and peer-reviewed literature
Do NOT take folic acid or folate supplements during capecitabine therapy unless specifically prescribed by your oncologist. Immediately disclose all supplements at every oncology visit. Stop any folic acid-containing supplements before starting capecitabine.
Why this interaction occurs
Capecitabine is converted to 5-fluorouracil (5-FU) in the body. Folate (particularly leucovorin/folinic acid) potentiates 5-FU toxicity by stabilizing the thymidylate synthase inhibitory complex, dramatically increasing risk of severe gastrointestinal toxicity (mucositis, diarrhea), myelosuppression, and potentially life-threatening adverse effects.
Evidence
Evidence level: strong.
Data source
PubMed: PMID 41305008
Reported safety data
The FDA’s adverse event reporting system (FAERS) has received 62,647 reports mentioning Capecitabine. This reflects reported cases involving the medication in general — not confirmed causation, and not specific to the Capecitabine + 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 Folic Acid interactions → · All Capecitabine interactions →
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Educational only — not medical advice.
Always confirm with your doctor or pharmacist.