A complete safety, timing, and dosage guide for combining Krill Oil with St. John's Wort — including how the two supplements interact, the best time of day to take each, and which populations should be careful.
Yes, you can take krill oil and St. John's Wort together. No known significant interaction exists between these two supplements, and they work through separate pathways.
Taking Krill Oil and St. John's Wort together is safe—they don't interfere with each other. Krill oil's omega-3s and St. John's Wort's active compounds act through independent mechanisms, so no significant interaction is expected. This combination is well-tolerated for most healthy adults.
Krill oil provides omega-3 fatty acids (EPA and DHA) bound to phospholipids, which are absorbed through intestinal lipid pathways and incorporated into cell membranes. St. John's Wort contains hypericin and hyperforin, which are absorbed separately and are known inducers of cytochrome P450 enzymes, especially CYP3A4 and P-glycoprotein. These enzymes primarily metabolize pharmaceutical drugs, not dietary lipids or phospholipids. Since omega-3s from krill oil are not substrates for CYP3A4 or P-glycoprotein, there is no metabolic competition or altered breakdown. Additionally, krill oil is anti-inflammatory and St. John's Wort has mild serotonergic effects, but these actions do not overlap or amplify each other, resulting in a neutral interaction profile.
For best results, take both supplements together with your morning meal: krill oil benefits from dietary fat, and morning dosing of St. John's Wort helps avoid insomnia. No spacing is required between them. If you take prescription medications, take St. John's Wort at least 2 hours apart from those medications to reduce any enzyme-mediated interference, but this is not necessary for krill oil. Choose high-quality krill oil certified by third-party sustainability programs and a standardized St. John's Wort extract to ensure consistent potency. If you miss a dose, take it as soon as you remember unless it's almost time for the next dose.
Krill oil is typically sold as softgels with phospholipid-bound EPA/DHA, which may offer better absorption than fish oil, but this does not alter the interaction with St. John's Wort. St. John's Wort is available as capsules, tablets, teas, and standardized extracts; choose a product standardized to 0.3% hypericin for consistent dosing. No specific formulation of either supplement changes the safety of combining them.
Yes, I can take them together. They don't compete for absorption or interact through any shared biological pathway. Taking both with a meal works well for me.
Yes, it is safe to take both daily. There are no known cumulative risks from combining these two supplements. I still need to be mindful of St. John's Wort's interactions with other medications I may take.
There is no need to wait at all; I can take them simultaneously. The only timing concern is separating St. John's Wort from prescription medications, but that has nothing to do with krill oil.
No, they do not compete. Krill oil's fat-soluble omega-3s are absorbed via chylomicrons and lymphatic transport, while St. John's Wort's compounds are absorbed through the small intestine by different pathways. No competition is expected.
Most people can take this combination safely. However, I should avoid St. John's Wort if I am pregnant, breastfeeding, or taking antidepressants, oral contraceptives, or cyclosporine. Krill oil should be used cautiously with blood-thinning medications.
I should take krill oil with food containing fat to improve absorption. St. John's Wort can be taken on an empty stomach, but taking it with a meal helps prevent stomach upset. Taking both with breakfast is my simplest approach.
Reviewed by Caroline M. on January 15, 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.