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Fluoxetine + St. Johns Wort

STOP — Contraindicated

🔴 STOP — Contraindicated. Do not take St. Johns Wort with Fluoxetine. This combination can cause serious harm or death.

Evidence level: STRONG

What this interaction means

St. John's Wort and Prozac should never be taken together. Combined serotonin boost can cause life-threatening Serotonin Syndrome.

How it works (mechanism)

Additive serotonergic effects. Both inhibit serotonin reuptake → Serotonin Syndrome risk.

Practical advice

Do NOT take St. Johns Wort and Fluoxetine together under any circumstances. If you are currently taking both, contact your doctor or pharmacist immediately — do not stop either medication abruptly without medical guidance.

Timing

Take Fluoxetine at the same time each day as prescribed. St. Johns Wort can be taken at any convenient time — morning with breakfast is most common. Some botanicals (St. John's Wort especially) have serotonergic activity and must NOT be combined with SSRIs. If you notice increased drowsiness or agitation, shift the botanical to a different time or discuss discontinuation with your prescriber.

Risk factors

Risk increases with higher doses of either substance, older age, liver or kidney impairment, and concurrent use of other serotonergic or CNS-depressant substances.

Symptoms to watch for

Agitation, confusion, rapid heartbeat, high blood pressure, dilated pupils, muscle twitching, diarrhea, high body temperature, seizures. Seek emergency care immediately.

What to tell your doctor

Show this page to your doctor. Ask: "I want to take St. Johns Wort but I'm on Fluoxetine. What safe alternatives do I have?"

Safer alternatives

Consider talking to your doctor about adjusting your antidepressant dose rather than adding St. Johns Wort. Safer supplement options for mood support include magnesium glycinate, omega-3 fish oil, or vitamin D3 — all with strong evidence and minimal drug interactions.

Frequently asked questions

Can I take Fluoxetine and St. Johns Wort together?

St. John's Wort and Prozac should never be taken together. Combined serotonin boost can cause life-threatening Serotonin Syndrome.

When should I take Fluoxetine vs St. Johns Wort?

Take Fluoxetine at the same time each day as prescribed. St. Johns Wort can be taken at any convenient time — morning with breakfast is most common. Some botanicals (St. John's Wort especially) have serotonergic activity and must NOT be combined with SSRIs. If you notice increased drowsiness or agitation, shift the botanical to a different time or discuss discontinuation with your prescriber.

What symptoms should I watch for if I combine Fluoxetine and St. Johns Wort?

Agitation, confusion, rapid heartbeat, high blood pressure, dilated pupils, muscle twitching, diarrhea, high body temperature, seizures. Seek emergency care immediately.

Are there safer alternatives to combining Fluoxetine with St. Johns Wort?

Consider talking to your doctor about adjusting your antidepressant dose rather than adding St. Johns Wort. Safer supplement options for mood support include magnesium glycinate, omega-3 fish oil, or vitamin D3 — all with strong evidence and minimal drug interactions.

What should I tell my doctor about taking Fluoxetine and St. Johns Wort?

Show this page to your doctor. Ask: "I want to take St. Johns Wort but I'm on Fluoxetine. What safe alternatives do I have?"

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