Is Grapefruit Safe with Sildenafil?
Free · No account · based on published sources including NIH ODS, FDA drug labels, and peer-reviewed literature
Avoid combining Grapefruit with Sildenafil — Grapefruit blocks the liver enzyme (CYP3A4) that processes Sildenafil, potentially raising Sildenafil levels to toxic range. Consult your doctor or pharmacist.
Why this interaction occurs
Furanocoumarins irreversibly inhibit intestinal CYP3A4. Result: increased drug levels. Can increase drug levels 2-5x — dangerous with many drugs
Evidence
Evidence level: strong.
Data source
PubMed: PMID 29703387, PMID 16365957
Reported safety data
The FDA’s adverse event reporting system (FAERS) has received 61,253 reports mentioning Sildenafil. This reflects reported cases involving the medication in general — not confirmed causation, and not specific to the Sildenafil + 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 interactions → · All Sildenafil interactions →
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Educational only — not medical advice.
Always confirm with your doctor or pharmacist.