Dangerous
St. John's wort
an herbal remedy for mood. Herbs & mushrooms.
Safety: Weakens many medicines, including the cancer drugs irinotecan, imatinib and docetaxel.
During treatment: Can weaken irinotecan, imatinib, docetaxel and many other medicines.
- Verdict
- DangerousIt causes direct harm, such as poisoning, whatever its claimed effect on cancer.
- How sure
- Rung 3 · ModerateConsistent observational studies or small trials, not yet confirmed by large trials.
The rung shows how sure the science is, not how big the effect is. How to read these ratings
Cancers affected
Anyone taking cancer drugs
What the evidence shows
In a small crossover study it cut levels of the active form of the chemotherapy drug irinotecan by 42%. The National Center for Complementary and Integrative Health warns it can weaken many medicines, including the cancer drugs irinotecan, imatinib and docetaxel.
What to do
Don't take it during cancer treatment. Tell your care team if you've been taking it.
Sources
To take it to your doctor, print this page.
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Related
Every supplement we rated, or follow one cancer step by step: breast cancer, colorectal cancer, lung cancer and prostate cancer.