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Grapefruit + Simvastatin

MAJOR — Use With Caution

🔴 MAJOR — Do NOT combine grapefruit with Simvastatin. Switch to pravastatin or rosuvastatin if you eat grapefruit regularly.

Evidence level: STRONG

What this interaction means

Grapefruit can increase simvastatin levels by up to 15 times. This dramatically raises the risk of severe muscle damage (rhabdomyolysis), a potentially life-threatening condition.

How it works (mechanism)

Furanocoumarins in grapefruit irreversibly inhibit intestinal CYP3A4, increasing simvastatin bioavailability up to 15-fold and raising risk of rhabdomyolysis.

Practical advice

Completely avoid grapefruit and grapefruit juice while taking simvastatin. Even small amounts are dangerous. Ask your doctor about switching to pravastatin or rosuvastatin, which are not affected.

Timing

Take Simvastatin in the evening. CRITICAL: Grapefruit and grapefruit juice inhibit CYP3A4 and can dramatically increase blood levels of atorvastatin, lovastatin, and simvastatin — this raises rhabdomyolysis risk. Pravastatin and rosuvastatin are less affected. Grapefruit can be consumed normally unless it is grapefruit.

Risk factors

Elderly, high-dose statin users, patients with kidney or liver disease

Symptoms to watch for

Unexplained muscle pain, dark urine, extreme fatigue, muscle weakness

What to tell your doctor

Ask about switching to pravastatin or rosuvastatin if grapefruit is part of your diet

Safer alternatives

Statin interactions often involve liver enzyme competition. Ask your doctor about alternative statins (rosuvastatin and pravastatin have fewer CYP interactions) or spacing doses 12 hours apart. CoQ10 supplementation may help with statin-related muscle discomfort.

Frequently asked questions

Can I take Grapefruit and Simvastatin together?

Grapefruit can increase simvastatin levels by up to 15 times. This dramatically raises the risk of severe muscle damage (rhabdomyolysis), a potentially life-threatening condition.

When should I take Grapefruit vs Simvastatin?

Take Simvastatin in the evening. CRITICAL: Grapefruit and grapefruit juice inhibit CYP3A4 and can dramatically increase blood levels of atorvastatin, lovastatin, and simvastatin — this raises rhabdomyolysis risk. Pravastatin and rosuvastatin are less affected. Grapefruit can be consumed normally unless it is grapefruit.

What symptoms should I watch for if I combine Grapefruit and Simvastatin?

Unexplained muscle pain, dark urine, extreme fatigue, muscle weakness

Are there safer alternatives to combining Grapefruit with Simvastatin?

Statin interactions often involve liver enzyme competition. Ask your doctor about alternative statins (rosuvastatin and pravastatin have fewer CYP interactions) or spacing doses 12 hours apart. CoQ10 supplementation may help with statin-related muscle discomfort.

What should I tell my doctor about taking Grapefruit and Simvastatin?

Ask about switching to pravastatin or rosuvastatin if grapefruit is part of your diet

Explore more interactions

Or browse the full interaction database (121,000+ pairs).