Basic Dosage of Fish Oil (EPA and DHA)
For general cardiovascular health in healthy adults, consume 400-500 mg of EPA+DHA daily, which can be achieved through eating fatty fish at least twice weekly, as recommended by the American Heart Association. 1, 2
Dosing by Clinical Indication
General Cardiovascular Health (Healthy Adults)
- 400-500 mg EPA+DHA daily is the target intake for primary prevention of coronary heart disease death 2, 3
- This dose provides a 37% reduction in risk for CHD death based on meta-analysis of U.S. epidemiologic studies 3
- Two servings per week of oily fish (8 ounces total) naturally provides this amount and is the preferred approach over supplementation 1, 2
- The International Society for the Study of Fatty Acids and Lipids specifically recommends 500 mg EPA+DHA daily for cardiovascular health maintenance 2
Documented Coronary Heart Disease (Secondary Prevention)
- 850-1,000 mg EPA+DHA daily is recommended for patients with established CHD 2, 4
- The GISSI-Prevenzione trial demonstrated a 45% reduction in sudden death with 850 mg EPA+DHA daily in post-MI patients 2
- This dose reduces myocardial infarction risk by 9% and total coronary disease by 7% 2
Hypertriglyceridemia
- 2-4 grams EPA+DHA daily under physician supervision for therapeutic triglyceride lowering 2, 5
- This dose reduces triglycerides by 20-40% (or 25-45% depending on baseline levels) 2, 5
- 4 grams daily is optimal for maximal triglyceride reduction 5
- Doses above 3 grams daily require physician monitoring due to potential bleeding risk 2
Plant-Based Alternative (ALA)
- 1.5-3 grams daily of alpha-linolenic acid (ALA) from sources like walnuts, flaxseeds, and canola oil for those who don't consume fish 2
- Note that ALA appears less potent than EPA and DHA for cardiovascular benefits 2
Critical Safety Considerations
Atrial Fibrillation Risk
- Doses ≥1 gram daily increase atrial fibrillation risk by 25%, with highest risk at 4 grams daily or more 2, 5, 6
- The REDUCE-IT trial (4 grams daily icosapent ethyl) showed hospitalization for atrial fibrillation in 3.1% vs 2.1% in controls 2
Bleeding Risk
- No increased bleeding risk with doses up to 4-5 grams daily, even with concurrent antiplatelet or anticoagulant therapy 2
- However, doses above 3 grams daily still warrant physician supervision as a precautionary measure 2
Upper Safety Limit
- The European Food Safety Authority establishes up to 5 grams daily combined EPA+DHA as safe for long-term supplementation without increased bleeding risk 2
Important Clinical Pitfalls
Supplement Quality Issues
- Over 70% of commercial fish oil supplements do not contain the stated label amount of EPA or DHA 7
- Only 21-25% of tested supplements had at least 100% of stated EPA or DHA content 7
- Most nonprescription fish oil products require 5 servings on average (range 1-34 servings) to achieve 2,000 mg EPA+DHA 8
Who Should NOT Take Fish Oil Supplements
- Healthy individuals without elevated triglycerides or established cardiovascular disease should not take nonprescription fish oil supplements, as they may cause harm, particularly at higher doses 6
- Dietary fish consumption (twice weekly) is preferred over supplementation for general health 6
Gastrointestinal Side Effects
- Common dose-dependent effects include fishy aftertaste, belching, gas, bloating, and nausea 2, 6
- Taking fish oil with meals reduces these side effects and improves adherence, though absorption occurs regardless of food timing 5
Practical Algorithm for Prescribing
No cardiovascular disease: Recommend 2 servings fatty fish weekly (no supplements needed) 1, 6
Established CHD: Prescribe 850-1,000 mg EPA+DHA daily 2
Hypertriglyceridemia (≥150 mg/dL): Prescribe prescription omega-3 products at 2-4 grams daily with monitoring 5, 6
Doses >3 grams daily: Require physician supervision with periodic monitoring 2