Is Folic Acid (Folate) Safe with methotrexate?
Free · No account · based on published sources including NIH ODS, FDA drug labels, and peer-reviewed literature
Take folic or folinic acid only as directed by your healthcare provider. Do not self-supplement with folic acid while on methotrexate for cancer without medical guidance.
Why this interaction occurs
Methotrexate competes with reduced folates for active transport across cell membranes. Coadministration of folic acid or its derivatives decreases the clinical effectiveness of methotrexate in patients with neoplastic diseases.
Evidence
Evidence level: strong.
Data source
FDA Drug Label
Reported safety data
The FDA’s adverse event reporting system (FAERS) has received 499,559 reports mentioning methotrexate. This reflects reported cases involving the medication in general — not confirmed causation, and not specific to the methotrexate + 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 (Folate) interactions → · All methotrexate interactions →
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Educational only — not medical advice.
Always confirm with your doctor or pharmacist.