Does omeprazole interact with fish oil supplements?

Short answer

There isn’t a well-documented, clinically significant interaction between omeprazole (a proton pump inhibitor for acid reflux) and standard fish oil (omega‑3) supplements. However, fish oil can modestly thin the blood and may lower blood pressure, so if you also take blood thinners or antihypertensive drugs alongside omeprazole, you might want to monitor for bleeding or low blood pressure and discuss dosing with your clinician. ^{[1] [2]}

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What each product does

• Omeprazole reduces stomach acid by blocking the gastric proton pump and can affect how certain prescription medicines work, mainly via stomach pH–related absorption changes and selective effects on drug‑metabolizing enzymes (CYP450, especially CYP2C19). ^{[3] [4]}

• Fish oil (omega‑3 fatty acids) supports heart and metabolic health but, especially at higher doses, can increase bleeding tendency and slightly lower blood pressure; it also has known interactions with specific medicines like anticoagulants and antiplatelet agents. ^{[1] [2]}

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Known interaction considerations

• Direct omeprazole–fish oil interaction: No specific, clinically important interaction is established between omeprazole and fish oil. Current data on omeprazole’s interactions focus on medicines such as clopidogrel, diazepam, phenytoin, and warfarin, not on omega‑3 supplements. ^{[3] [5]}

• Bleeding risk context: Fish oil can increase bleeding risk, particularly when combined with anticoagulants (e.g., warfarin), antiplatelets (e.g., clopidogrel), or high doses of omega‑3. Omeprazole itself does not increase bleeding risk and is often used to protect the stomach in people taking antiplatelets, but if you take antiplatelets/anticoagulants with fish oil, the additive bleeding risk is a consideration. ^{[1] [2]}

• Blood pressure effects: Fish oil may slightly lower blood pressure; if you are on antihypertensive medications, the effects can add up. Omeprazole does not lower blood pressure, so any blood pressure change would be attributable to fish oil or your other medications. ^{[6] [2]}

• Absorption and metabolism: Omeprazole changes stomach acidity and has selective CYP interactions (not broad). There is no strong evidence that omeprazole impairs omega‑3 absorption or significantly alters fish oil metabolism. Notably, another drug (orlistat) can reduce fish oil absorption, but this is unrelated to omeprazole. ^{[4] [6]}

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Practical guidance

• Typical doses are generally fine: For most users taking standard doses of fish oil (e.g., 1,000 mg combined EPA/DHA daily) with omeprazole, no meaningful interaction is expected. ^[1]

• If you use blood thinners or antiplatelets: Consider checking with your clinician before adding fish oil, monitor for unusual bruising, nosebleeds, or bleeding gums, and keep doses moderate. Fish oil’s bleeding tendency is the key issue, not omeprazole. ^{[1] [2]}

• If you have low blood pressure or take antihypertensives: Monitor your blood pressure when starting or increasing fish oil since it can modestly lower BP. ^[6]

• Timing and tolerance tips: Omeprazole is best taken before meals; fish oil can be taken with food to reduce fishy aftertaste or reflux. If fish oil causes heartburn or nausea, splitting the dose or using enteric‑coated capsules may help. ^[1]

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Safety notes and when to seek advice

• Side effects to watch for: Fish oil can cause a fishy aftertaste, heartburn, nausea, diarrhea, or skin rash; these are more common with higher doses. If you notice easy bruising or prolonged bleeding, reduce the dose and contact your clinician especially if you’re on blood thinners. ^[1]

• Medication list matters: Omeprazole can interact with certain prescription medicines (e.g., clopidogrel, methotrexate, diazepam, phenytoin, warfarin), so ensure your clinician or pharmacist reviews your full medication and supplement list. ^{[3] [5]}

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Summary table

Topic	Omeprazole	Fish oil (omega‑3)	Net implication together
Primary action	Lowers stomach acid. [3]	Cardiometabolic support; anti‑inflammatory. [1]	No direct conflict expected.
Bleeding risk	Neutral; no direct increase. [5]	May increase bleeding, especially with anticoagulants/antiplatelets. [1] [2]	Monitor if you use blood thinners; omeprazole does not counteract fish oil’s bleeding tendency.
Blood pressure	No lowering effect. [5]	Can slightly lower BP. [6]	Watch BP if on antihypertensives.
Absorption/metabolism	Alters gastric pH; selective CYP effects (limited, mainly CYP2C19). [4]	No major CYP issues; absorption unaffected by omeprazole per current evidence. [4]	Interaction unlikely; take fish oil with food for tolerance. [1]

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Bottom line

Based on current evidence, taking omeprazole with standard fish oil supplements is generally considered safe, with no direct, clinically significant interaction. The main considerations are fish oil’s potential to increase bleeding and to lower blood pressure especially if you also use blood thinners or antihypertensive medications. ^{[1] [2]}