St John's Wort … Safety & Interactions
Guan Ye Lian Qiao · Herba Hyperici Perforati
Contraindicated / High risk. Use only under practitioner supervision.
Contraindications
- Concomitant use with medicines where reduced drug exposure or serotonergic toxicity would be dangerous
- Bipolar-spectrum mood instability without supervision
- Pregnancy
Cautions
- Memorial Sloan Kettering and major pharmacology reviews warn that St John's Wort can reduce effectiveness of oral contraceptives, transplant drugs, HIV drugs, anticoagulants, and many other medicines through enzyme and transporter induction.
- Photosensitivity and agitation are possible, especially at higher doses or in susceptible patients.
- The herb should not be treated as a casual wellness supplement when complex medication regimens are present.
Drug Interactions
| Drug Class / Substrate | Mechanism | Severity | Source |
|---|---|---|---|
| SSRIs, SNRIs, MAO inhibitors, triptans, and other serotonergic drugs ... increased risk of serotonergic adverse effects | |||
| Cyclosporine, tacrolimus, and related transplant immunosuppressants ... reduced drug levels | |||
| Oral contraceptives ... reduced contraceptive reliability | |||
| Many CYP3A4 or P-glycoprotein substrate drugs ... reduced exposure and therapeutic failure risk | |||
Pregnancy
Not recommended during pregnancy. Consult a qualified practitioner before any use.
This information is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider before using herbal medicines, especially if you take prescription medications.