St Johns Wort × Ssri Interaction — Severity, Mechanism & Management

⚠️ Mechanism

St. John's wort inhibits serotonin reuptake and induces CYP enzymes that metabolize SSRIs. Combined use risks serotonin syndrome.

📋 Effect

Serotonin syndrome (agitation, confusion, tachycardia, hyperthermia); also reduced SSRI efficacy via enzyme induction

💊 Management

Avoid combination. Serotonin syndrome can be life-threatening. Allow 2-week washout between St. John's wort and SSRIs.

Plain Language Summary

This combination is dangerous. Taking St. John's Wort with an SSRI can cause a life-threatening buildup of serotonin in your body and may also make your medication less effective.

Source

FDA MedWatch; Nemeroff CB et al. J Clin Psychiatry 2005

Supporting Research

The effect of Hypericum perforatum on postmenopausal symptoms and depression: A randomized controlled trial PMID:31331546 DOI:10.1016/j.ctim.2019.05.028 2019

Hypericum extract LI 160 and fluoxetine in mild to moderate depression: a randomized, placebo-controlled multi-center study in outpatients PMID:15538592 2005

[Hypericum perforatum extract in treatment of mild to moderate depression. Clinical and pharmacological aspects] PMID:12212522 2002

Hypericum perforatum versus fluoxetine in the treatment of mild to moderate depression PMID:12008860 2002

Efficacy of continuation treatment with hypericum perforatum in depression PMID:12019675 2002

Predicting stable treatment response in patients with major depression treated with hypericum extract WS 5570/5572 PMID:16189745 2005

Adverse Event Profile: St Johns Wort 0

Medical Disclaimer: This interaction record is for informational and educational purposes only and does not constitute medical advice. Drug-supplement interactions can be dangerous. Always consult your healthcare provider or pharmacist before combining any supplement with prescription medications. Do not stop or change any medication without professional guidance.