Can I take St john's wort and Vitamin b2 together?
Drug interaction guide
Originally published 25 Jan 2026
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There is no known harmful interaction between St John's Wort and Vitamin B2 (riboflavin). Taking them together is generally considered safe.
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Why this happens
St John's Wort is known for affecting how the liver processes many medicines (via the CYP450 enzyme system), but Vitamin B2 is a water-soluble vitamin that is not processed in a way that interferes with this herbal supplement. They do not compete for the same pathways in the body.
What you should do
Back to contentsYou can take these two together. However, always inform your doctor or pharmacist about all supplements you are taking, as St John's Wort can interact with many prescription medications, such as blood thinners, birth control, and antidepressants.
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Using other medicines
Back to contentsTaking multiple medicines? Our Medicines Interaction Checker helps you check whether your prescriptions, over-the-counter medicines, and supplements are safe to take together. Simply search for your medicines to see potential interactions and what to do about them.
Disclaimer
This information is for general educational purposes only and should not be relied upon as a substitute for professional medical advice. Always consult your GP, pharmacist, or another qualified healthcare professional before making decisions about your medications. Individual circumstances may vary, and only a healthcare professional who knows your medical history can provide personalised guidance.
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Article history
The information on this page is written and peer reviewed by qualified clinicians.
25 Jan 2026 | Originally published
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