Is Grapefruit / Grapefruit Juice Safe with Simvastatin?
Free · No account · based on published sources including NIH ODS, FDA drug labels, and peer-reviewed literature
Avoid grapefruit and grapefruit juice entirely while taking simvastatin. Even a single glass can significantly raise simvastatin blood levels, increasing the risk of severe muscle damage (rhabdomyolysis) and liver toxicity.
Why this interaction occurs
Grapefruit contains furanocoumarins (e.g., bergamottin) that irreversibly inhibit intestinal CYP3A4, the primary enzyme responsible for simvastatin metabolism. This inhibition dramatically increases simvastatin bioavailability, elevating plasma concentrations by up to 3-fold, greatly increasing the risk of myopathy and rhabdomyolysis.
Evidence
Evidence level: strong.
Reported safety data
The FDA’s adverse event reporting system (FAERS) has received 213,170 reports mentioning Simvastatin. This reflects reported cases involving the medication in general — not confirmed causation, and not specific to the Simvastatin + 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 Grapefruit / Grapefruit Juice interactions → · All Simvastatin interactions →
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Educational only — not medical advice.
Always confirm with your doctor or pharmacist.