Is NAC (N-Acetylcysteine) Safe with Cyclophosphamide?
Free · No account · based on published sources including NIH ODS, FDA drug labels, and peer-reviewed literature
Avoid high-dose NAC supplementation during cyclophosphamide-based chemotherapy regimens unless prescribed for hemorrhagic cystitis prevention under medical supervision. Discuss all supplement use with your care team.
Why this interaction occurs
Cyclophosphamide metabolites (particularly acrolein and phosphoramide mustard) cause cytotoxicity through DNA alkylation and oxidative stress. NAC's antioxidant and thiol-donating properties may reduce the oxidative component of cytotoxicity in tumor cells. Note: NAC (as Mesna equivalent) is used clinically to prevent bladder toxicity, but unsupervised supplemental use may interfere with antitumor activity.
Evidence
Evidence level: moderate.
Reported safety data
The FDA’s adverse event reporting system (FAERS) has received 187,497 reports mentioning Cyclophosphamide. This reflects reported cases involving the medication in general — not confirmed causation, and not specific to the Cyclophosphamide + 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 NAC (N-Acetylcysteine) interactions → · All Cyclophosphamide interactions →
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Educational only — not medical advice.
Always confirm with your doctor or pharmacist.