fatty acid · for high blood pressure
Omega-3
Helps arteries stay flexible and relaxed, which lowers the pressure inside them.
Say that in clinical terms
Omega-3s reduce blood pressure by improving endothelial function, increasing nitric oxide bioavailability, reducing arterial stiffness, and decreasing production of vasoconstrictive thromboxane A2. EPA and DHA also reduce triglycerides.
How strong is the research?
2 papers read, 2 supporting.
Who was studied: Adults with high or borderline blood pressure. The effect is largest in those untreated and much smaller otherwise.
How much to take
daily with meals
2000–3000 mg
Higher doses (2-3g EPA+DHA) show greater BP reduction. Take consistently with food.
Before you take it
- FDA GRAS limit for dietary supplements: up to 5 g/day of combined EPA+DHA (not 3 g/day; the lower figure reflects an older FDA enforcement discretion letter, not the current GRAS determination).
- No formal Tolerable Upper Intake Level (UL) has been established by the IOM/NAM for EPA or DHA.
- Doses of 2–15 g/day may increase bleeding time by reducing platelet aggregation; clinically relevant when combined with anticoagulants (warfarin), antiplatelet agents (aspirin, clopidogrel), or NSAIDs.
- INR monitoring is advisable when omega-3 supplements are added to warfarin therapy; most evidence suggests doses of 3–6 g/day do not significantly alter anticoagulant status, but individual variation exists.
- Extended use at 4 g/day in individuals with established CVD or at high CVD risk is associated with a modestly increased risk of atrial fibrillation (documented in STRENGTH and REDUCE-IT trials).
- High doses (≥900 mg EPA plus 600 mg DHA/day) may reduce immune function.
- Omega-3 may add to the blood-pressure-lowering effect of antihypertensive medications; blood pressure monitoring is advisable when initiating supplementation in patients already on antihypertensive therapy.
- Common side effects include fishy aftertaste, belching, gastrointestinal discomfort, and nausea; these are dose-dependent and usually mild.
- Individuals with fish or shellfish allergies should verify product sourcing; algal EPA/DHA is a fish-free alternative.
- Oxidized (rancid) fish oil may have pro-inflammatory effects; product freshness and storage conditions matter.
- At doses of 2000–3000 mg/day (as recommended for this indication), omega-3 may potentiate antihypertensive medications — blood pressure monitoring is recommended when adding supplementation to existing antihypertensive therapy.
When to take it
Best taken: with food
What we make of it
Consistently replicated, but the effect is small.
The detail
Blood pressure lowering is one of the more reliably reproduced omega-3 effects and the pooled analysis is from a proper academic journal. The size of the drop is modest.