A complete safety, timing, and dosage guide for combining Cod Liver 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 St. John's Wort and cod liver oil together safely; no significant interaction has been reported between the two supplements.
St. John's Wort and cod liver oil together are considered safe for most healthy adults. They work through separate biological pathways, so one does not interfere with the other. Cod liver oil provides omega-3 fatty acids plus vitamins A and D, while St. John's Wort is an herbal extract used for mood support.
St. John's Wort is a strong inducer of cytochrome P450 enzymes, particularly CYP3A4, CYP2C9, and CYP2C19, as well as the efflux transporter P-glycoprotein. These enzymes metabolize many drugs, which is why St. John's Wort can lower the blood levels of certain medications. Cod liver oil, on the other hand, contains long-chain omega-3 fatty acids (EPA and DHA) and fat-soluble vitamins A and D. These nutrients are absorbed through the lymphatic system along with dietary fat and are not primarily broken down by the cytochrome P450 enzymes that St. John's Wort induces. Because there is no overlapping metabolic pathway or direct competition for absorption, the two supplements act independently in the body. Taking them together does not create any known pharmacological conflict.
Take St. John's Wort and cod liver oil together at breakfast or lunch with a meal that includes some fat. This supports absorption of the fat-soluble vitamins in cod liver oil and may reduce the mild stomach upset some people experience from St. John's Wort. If you prefer, you can take them at separate meals, but there is no need to wait a specific amount of time between them. If you miss a dose of either supplement, take it at your next meal and do not double up. Choose a cod liver oil supplement that supplies a moderate amount of vitamin A (about 1,500 to 2,500 IU per serving) to avoid excess accumulation.
St. John's Wort is available as tablets, capsules, teas, and liquid extracts, but the form does not change the lack of interaction with cod liver oil. Cod liver oil comes as a liquid or in softgels, and both are absorbed equally well when taken with a fatty meal. If you are using a standardized St. John's Wort extract with a known hyperforin content, that only matters for drug interactions, not for cod liver oil. Liquid cod liver oil may be more prone to rancidity, so store it in the refrigerator after opening.
St. John's Wort is often paired with omega-3 fish oil in mood-support stacks, but cod liver oil is less common in these products because it also provides vitamins A and D. You may occasionally see cod liver oil included in broad multivitamin formulas or general wellness oils alongside other oils, but this specific pair is not a standard commercial stack.
Yes, you can take St. John's Wort and cod liver oil at the same time. The two supplements do not interfere with each other's absorption or breakdown. Taking them together with a meal that contains fat will help your body absorb the cod liver oil properly.
Yes, it is safe for most people to combine St. John's Wort and cod liver oil every day. There is no known interaction that would make daily use risky. Just be aware that cod liver oil provides vitamin A, so you should not take extra vitamin A supplements to avoid exceeding the safe upper limit.
You do not need to wait any specific amount of time between St. John's Wort and cod liver oil. They can be taken together at the same meal. If you notice digestive discomfort, you can separate them by a few hours, but this is not necessary.
No, St. John's Wort and cod liver oil do not compete for absorption. St. John's Wort is absorbed into the bloodstream and then metabolized by liver enzymes, while cod liver oil is digested as fat and absorbed through the lymphatic system. They use different pathways, so there is no competition.
People who should avoid St. John's Wort, such as those taking antidepressants, blood thinners, birth control pills, or immunosuppressants, should not take this combination. Pregnant women should also avoid St. John's Wort and be cautious with cod liver oil because of vitamin A. Always check with your doctor or pharmacist if you fall into any of these categories.
Take both St. John's Wort and cod liver oil with food. Cod liver oil is fat-soluble, so it needs dietary fat for optimal absorption. St. John's Wort is less likely to cause stomach irritation when taken with a meal, which also helps you stay consistent with your routine.
Reviewed by Caroline M. on April 4, 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.