Protocols › Omega-3 fatty acids

Omega-3 for blood pressure

Goal: What trials of EPA and DHA used for blood pressure, and how much it fell.

Each protocol describes what studies used, for one goal or for one group of people. It is not advice for you: talk to a doctor before you start a supplement.

Updated 9 Nov 2026
Dose

A review of 71 trials found the largest fall at 2 to 3 g of EPA and DHA a day. The trials gave a median of 2.8 g a day.[1]

Form

EPA, DHA or both.[1] One plant trial gave 30 g of milled flaxseed a day in foods.[2]

What studies found

In 71 trials with 4,973 adults, 2 g a day lowered systolic pressure by 2.6 mmHg and diastolic by 1.6 mmHg. At 3 g a day the falls were 2.6 and 1.8 mmHg.[1] The fall was larger in people with high blood pressure or high blood fats, and in older people.[1] A 2020 Cochrane review found little or no effect on blood pressure.[3] In one 6-month trial in 110 people with peripheral artery disease, flaxseed lowered systolic pressure by about 10 mmHg.[2]

Ask a doctor first

Fish oil may prolong clotting times when taken with warfarin.[4] In two large trials, 4 g a day for several years slightly raised atrial fibrillation in people with heart disease or at high risk of it.[4]

People who take blood pressure medicine, a blood thinner or any other daily medicine should ask a doctor or pharmacist first.[4]

References

  1. Omega-3 Polyunsaturated Fatty Acids Intake and Blood Pressure: A Dose-Response Meta-Analysis of Randomized Controlled Trials. Zhang X, Ritonja JA, Zhou N, Chen BE, Li X J Am Heart Assoc, 2022. PMID 35647665
  2. Potent antihypertensive action of dietary flaxseed in hypertensive patients. Rodriguez-Leyva D, Weighell W, Edel AL, LaVallee R, Dibrov E, Pinneker R, et al. Hypertension, 2013. PMID 24126178
  3. Omega-3 fatty acids for the primary and secondary prevention of cardiovascular disease. Abdelhamid AS, Brown TJ, Brainard JS, Biswas P, Thorpe GC, Moore HJ, et al. Cochrane Database Syst Rev, 2020. PMID 32114706
  4. Omega-3 Fatty Acids: Fact Sheet for Health Professionals. NIH Office of Dietary Supplements. ods.od.nih.gov