Is Milk Thistle Safe with Tacrolimus?
Free · No account · based on published sources including NIH ODS, FDA drug labels, and peer-reviewed literature
Avoid concurrent use without specialist supervision. If use is unavoidable, intensive therapeutic drug monitoring of tacrolimus trough levels is required. Any signs of nephrotoxicity or neurotoxicity should be reported immediately.
Why this interaction occurs
Silymarin inhibits CYP3A4 and P-glycoprotein, both critical to tacrolimus metabolism and efflux. Inhibition can significantly increase tacrolimus bioavailability and systemic exposure, leading to dose-dependent toxicities including nephrotoxicity and neurotoxicity. Case reports document clinically significant tacrolimus level elevations with co-administration.
Evidence
Evidence level: moderate.
Data source
PubMed: PMID 22139684, PMID 15916450
Reported safety data
The FDA’s adverse event reporting system (FAERS) has received 130,929 reports mentioning Tacrolimus. This reflects reported cases involving the medication in general — not confirmed causation, and not specific to the Tacrolimus + 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 Milk Thistle interactions → · All Tacrolimus interactions →
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Educational only — not medical advice.
Always confirm with your doctor or pharmacist.