Omega-3 Dosage for Adults
For general cardiovascular health in typical adults without specific disease, consume 400-500 mg/day of combined EPA+DHA, achievable through eating fatty fish twice weekly or taking a 500 mg daily supplement if fish consumption is inadequate. 1, 2, 3
Baseline Recommendations for Healthy Adults
The American Heart Association recommends all adults eat fatty fish at least twice weekly, which naturally provides approximately 400-500 mg/day of EPA+DHA combined. 1, 2, 3
For those who don't regularly consume fish, a daily supplement providing 500 mg EPA+DHA serves as baseline cardiovascular protection. 1, 3
This dosing reduces risk for coronary heart disease death by approximately 37% based on meta-analysis of U.S. epidemiologic studies. 4
Plant-based omega-3 sources (ALA from flaxseed, walnuts, canola oil) are significantly less effective—requiring 1.5-3 grams daily because conversion to EPA is only 6% and to DHA merely 3.8%. 1, 3
Condition-Specific Dosing Algorithm
For Documented Coronary Heart Disease (Secondary Prevention)
Prescribe 1 gram (850-1,000 mg) EPA+DHA daily, which reduces sudden cardiac death by 45% and total mortality by 15%. 1, 2, 3
This recommendation carries Grade A evidence from the landmark GISSI-Prevenzione trial involving 11,324 post-MI patients. 1, 3
The protective effect manifests within 3-4 months of starting supplementation. 3
Both the American College of Cardiology and American Heart Association endorse this dosing. 1, 3
For Hypertriglyceridemia
For severe hypertriglyceridemia (≥500 mg/dL), prescribe 4 grams/day EPA+DHA under physician supervision, which reduces triglycerides by approximately 45% and VLDL cholesterol by more than 50%. 2, 5
For moderate hypertriglyceridemia (200-499 mg/dL), prescribe 2-4 grams/day EPA+DHA under physician supervision for optimal triglyceride lowering (≥30% reduction). 2, 5
The REDUCE-IT trial demonstrated a 25% reduction in major adverse cardiovascular events with 4 grams/day of EPA in high-risk patients with elevated triglycerides on statin therapy. 2
For Diabetes
Do not prescribe omega-3 supplements for diabetes management—evidence shows no benefit for glycemic control or primary cardiovascular prevention in diabetes. 6, 1
The American Diabetes Association systematic review of seven RCTs found omega-3 supplementation did not improve glycemic control or reduce cardiovascular events in diabetic patients. 6
However, the general recommendation for eating fatty fish twice weekly still applies to diabetic patients for overall health benefits. 6
Safety Thresholds and Monitoring Requirements
Upper Safety Limits
Long-term supplementation up to 5 grams EPA+DHA daily is safe without increased bleeding risk, even with concurrent anticoagulants or antiplatelet therapy. 1, 2
The European Food Safety Authority confirms EPA alone up to 1.8 grams/day has been specifically validated as safe. 2
No increased bleeding occurs even with concurrent warfarin or aspirin at doses up to 4 grams daily. 1, 3
Critical Safety Concern
High-dose omega-3 supplementation (≥4 grams daily) increases atrial fibrillation risk by 25%, with most increased risk occurring at doses >1 gram daily. 1, 2, 3
The REDUCE-IT trial documented hospitalization for atrial fibrillation in 3.1% versus 2.1% in controls with 4 grams daily. 2
Monitoring Protocol
Patients taking >3 grams daily require physician supervision, though this is for monitoring compliance and side effects rather than bleeding risk. 1, 2, 5
Common dose-limiting factors are mild gastrointestinal symptoms (fishy taste, belching, nausea), not safety concerns. 2, 3
Practical Implementation
Achieving Target Omega-3 Index
To achieve an Omega-3 Index ≥8% (associated with optimal cardiovascular protection), most adults require 1,000-1,500 mg/day EPA+DHA as triglycerides for at least 12 weeks. 7
Following the American Heart Association guideline of 1-2 seafood meals weekly does not achieve an Omega-3 Index ≥8% even with supplementation unless combined with approximately 1,100 mg/day supplemental EPA+DHA. 8
Supplements composed of triglycerides are more bioavailable and effective than ethyl ester formulations. 7
Common Pitfall to Avoid
Most Americans consume only 23 mg/day EPA and 63 mg/day DHA from food—far below the 400-500 mg/day recommendation—making supplementation necessary for most adults who don't regularly eat fatty fish. 9
The median intake of fish high in omega-3 fatty acids is only 0.07 oz/day in U.S. adults, well below the recommended two 3.5-oz servings weekly. 9