A complete safety, timing, and dosage guide for combining St. John's Wort with Fish Oil (Omega-3: EPA / DHA) — including how the two supplements interact, the best time of day to take each, and which populations should be careful.
Yes, you can take fish oil (omega-3 EPA/DHA) with St. John's Wort safely — there is no significant interaction between them.
Fish Oil (Omega-3: EPA / DHA) and St. John's Wort together are safe to combine, with no significant interaction. They work through different pathways, so taking them simultaneously does not affect absorption or effectiveness. Still, anyone on other medications should review St. John's Wort interactions first.
St. John's Wort acts primarily by inducing cytochrome P450 enzymes (especially CYP3A4 and CYP2C19), which can speed up the breakdown of many drugs and reduce their blood levels. Omega-3 fatty acids (EPA and DHA), however, are not processed to any meaningful degree by these enzymes — they are incorporated into cell membranes and metabolized through beta-oxidation and eicosanoid pathways. They also do not compete for the same transporters, receptors, or absorption carriers in the gut. St. John's Wort has mild serotonergic activity, while fish oil has anti-inflammatory and vasodilatory effects, but these are neither additive nor antagonistic at typical supplement doses. Because of these separate biological routes, no clinically relevant pharmacokinetic or pharmacodynamic interaction occurs between them.
If you choose to take both, take them together at breakfast or lunch with food — the fat in the meal helps fish oil absorption, and St. John's Wort is fine with or without food. There is no need to space them; if you prefer to take them separately, a gap of 15–30 minutes away from the meal will not change anything. If you miss a dose, skip it if it is close to your next dose; never double up. For best quality, use a fish oil with at least 500 mg combined EPA/DHA per capsule and a St. John's Wort product standardized to 0.3% hypericin.
Form is unlikely to change the interaction. Free fatty acid (FFA) fish oils may absorb slightly better than ethyl ester forms, but that does not affect St. John's Wort. St. John's Wort extract is usually standardized to 0.3% hypericin, and tablets, capsules, or liquids all behave similarly when combined with fish oil. Choose reliable, reputable brands for both to ensure purity and accurate dosing.
This pair is not commonly bundled in a single commercial stack, but fish oil frequently appears in cardiovascular formulas alongside CoQ10 and magnesium, while St. John's Wort is often found in mood-support blends with B vitamins and vitamin D.
Yes, you can take them at the same time. They do not affect each other's absorption or effectiveness, so there is no need to separate them. Taking them together with breakfast is a convenient way to remember both.
Yes, it is safe for most adults to combine these every day when following the recommended doses on the label. I would just remind you to check with your healthcare provider if you take other medications, especially antidepressants or anticoagulants.
No waiting time is needed; you can take them together. If you prefer to stagger them, even 15–30 minutes apart is fine, but it is not required.
No, they do not compete for absorption. Fish oil is absorbed with dietary fat, while St. John's Wort contains hypericin and hyperforin that use different absorption pathways, so no meaningful competition exists.
Most healthy adults can take them together, but avoid St. John's Wort if you are pregnant, breastfeeding, or taking SSRIs, oral contraceptives, cyclosporine, or anticoagulants without medical approval. Fish oil is generally safe, but if you have a bleeding disorder or upcoming surgery, check with your doctor first.
Take fish oil with food, especially a meal containing fat, to improve absorption. St. John's Wort can be taken with or without food, so taking both together with a meal is the best approach.
Reviewed by Caroline M. on April 14, 2026 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.