A complete safety, timing, and dosage guide for combining St. John's Wort with Ginkgo Biloba — including how the two supplements interact, the best time of day to take each, and which populations should be careful.
Yes, you can take St. John's Wort and Ginkgo Biloba together; they are considered safe to combine with no significant interaction reported.
St. John's Wort and Ginkgo Biloba together are generally safe for healthy adults, with no significant interaction between the two. The liver-enzyme effects of St. John's Wort do not alter how ginkgo's active compounds are handled. Still, both herbs influence clotting and mood pathways, so monitoring is wise if you take medications.
St. John's Wort strongly induces cytochrome P450 enzymes, particularly CYP3A4 and CYP2C19, as well as the drug transporter P-glycoprotein, which speeds up the breakdown of many prescription drugs. Ginkgo biloba's active constituents (flavonoids and terpene lactones) are not primarily metabolized by these same CYP3A4 pathways in clinically significant amounts, so their blood levels are not meaningfully reduced by St. John's Wort. The two herbs also act on separate physiological targets: ginkgo inhibits platelet-activating factor and has mild antioxidant properties, while St. John's Wort inhibits serotonin reuptake and mildly modulates dopamine and norepinephrine. Because these mechanisms are distinct and do not compete for receptor binding or absorption, no inherent interaction occurs. The only shared area of concern is a theoretical additive effect on bleeding and serotonin levels, but typical doses do not push most people into a danger zone.
Take both supplements with breakfast to build a simple daily habit and place the enzyme-inducing effect of St. John's Wort early in the day. For most adults, splitting St. John's Wort into two smaller doses (morning and afternoon) and taking ginkgo in the morning is sensible, but a single combined dose works too. Always use standardized extracts and avoid taking them with grapefruit juice, which may interfere with enzyme activity. If you miss a dose, resume with the next scheduled dose and do not compensate for the missed one. When possible, have your doctor review your complete supplement list to ensure the herbal combination does not interact with other medicines you take.
Standardized extracts matter for predictable dosing. For St. John's Wort, look for products standardized to 0.3% hypericin or 3–5% hyperforin, as hyperforin is the main enzyme inducer. For Ginkgo biloba, the standardized extract EGb 761 (containing 24% flavone glycosides and 6% terpene lactones) is the most widely studied form. No form-specific difference in the way these two interact has been identified, so choose high-quality extracts from reputable manufacturers.
This pair occasionally appears in herbal blends marketed for memory and mood support, sometimes alongside Bacopa monnieri, lion's mane mushroom, or Panax ginseng. They are not a standard industrial stack, so always read the label of any 'cognitive vitality' formula you consider.
Yes, you can take them together at the same time. I generally advise taking them with a meal to minimize stomach irritation. No significant interaction has been reported for this exact combination.
Yes, it is safe for most healthy adults to combine them daily. I recommend using standardized extracts and staying within the labeled dose range. However, if you are on antidepressants or blood thinners, I would first check with your doctor because these herbs can amplify those medications' effects.
You do not need to wait between them; taking them at the same time is fine. If you are also taking prescription medication, you can space everything by about 2 hours, but that will not prevent St. John's Wort from influencing how your other drugs are processed.
No, they do not appear to compete for absorption. Their active compounds use different uptake pathways, and the enzyme induction caused by St. John's Wort does not significantly affect ginkgo's bioavailability. I would still take them with food for the most consistent absorption.
People taking SSRIs, SNRIs, MAOIs, triptans, anticoagulants, antiplatelet drugs, or hormonal contraceptives should avoid combining these herbs without careful medical supervision. Pregnant and breastfeeding women should also avoid them. If you have bipolar disorder, epilepsy, or upcoming surgery, talk to your doctor first.
I recommend taking both with food, especially a meal containing a little fat, because this can improve absorption of fat-soluble plant compounds and reduce the chance of nausea. Taking them at breakfast makes the routine easier to remember. If you do take them on an empty stomach, it is fine but may be more likely to bother your stomach.
Reviewed by Caroline M. on April 8, 2025 for accuracy against the sources listed above. This page is educational and is not a substitute for professional medical advice.
The matrix has 86 supplements and 7310 pairwise interactions. Click any cell to see the full breakdown.