Fish oil delivers EPA and DHA — the two omega-3 fatty acids your body actually uses. Backed by 138 RCTs, 20 meta-analyses, and 243,000+ participants, our research confirms fish oil reliably and significantly reduces triglycerides. It also shows meaningful benefits for depression symptoms and inflammatory conditions. However, it does NOT reduce cardiovascular events (heart attacks, strokes) in most populations — a critical distinction that many supplement companies ignore. At high doses (>1g/day), there's a dose-dependent atrial fibrillation risk in people with cardiovascular disease.
May raise HbA1c
Monitor HbA1c if diabetic.
Mildly raises drug levels
Monitor drug levels.
Raises drug levels
Inform transplant team. Keep fish oil dose consistent.
Raises drug levels
May help personalize dosing.
May reduce vitamin E effects
Not clinically concerning at normal doses.
May raise drug levels
Be aware if on multiple CYP3A4 substrates.
Additive BP reduction
Monitor BP. Usually beneficial.
Reduces fish oil absorption
May reduce fish oil effectiveness.
This is a major issue for fish oil. Key concerns:
Not Prohibited. Not on the 2026 WADA list.
This is a major issue for fish oil. Key concerns:
Higher-dose omega-3 (>1g/day) associated with greater reduction in cardiovascular events, but atrial fibrillation risk increases proportionally.
Bernasconi AA et al. Effect of Omega-3 Dosage on Cardiovascular Outcomes: An Updated Meta-Analysis.. Mayo Clin Proc (2021). PMID: 34521376
Marine omega-3 supplementation associated with lower risk of MI, CHD death, and total CHD.
Hu Y et al. Marine Omega-3 Supplementation and Cardiovascular Disease: An Updated Meta-Analysis of 13 Randomized Controlled Trials.. J Am Heart Assoc (2019). PMID: 31567003
Omega-3 supplementation had significant clinical benefit for depression, with EPA-predominant formulations showing the strongest effect.
Liao Y et al. Efficacy of omega-3 PUFAs in depression: A meta-analysis.. Transl Psychiatry (2019). PMID: 31816544
AHA Science Advisory — 4g/day of EPA+DHA reduces triglycerides by 20-30%.
Skulas-Ray AC et al. Omega-3 Fatty Acids for the Management of Hypertriglyceridemia.. Circulation (2019). PMID: 29387889
Marine omega-3 supplementation associated with increased risk of atrial fibrillation, with risk increasing at higher doses.
Gencer B et al. Effect of Long-Term Marine Omega-3 Fatty Acids Supplementation on the Risk of Atrial Fibrillation.. J Am Coll Cardiol (2021). PMID: 34400635
Based on independent third-party laboratory analysis
Category pass rate: ~90% of fish oil products passed content testing. Rancidity is the primary failure mode — ~10% of products are already oxidized before opening.
Contamination risk: MODERATE. All tested products passed heavy metal testing. Mercury, lead, cadmium all below detection limits. Fish oil purification processes (molecular distillation) effectively remove contaminants.
Reviewed by the Scan Dose Research Team and Clinical Advisory Board | Last updated: April 5, 2026
Not medical advice. Based on published clinical research and systematic reviews.
Safety
Dangerous interactions. Talk to your prescriber before using this supplement if you take any of these.
Warfarin (Coumadin)
Omega-3 inhibits platelet aggregation, producing an additive anticoagulant effect on top of warfarin.
Source: PMID: 25062404
Clopidogrel (Plavix)
Dual antiplatelet effect.
Source: FDA label
High-dose Aspirin
Additive antiplatelet effect.
Source: Clinical consensus
Moderate interactions. Monitoring, timing separation, or dose adjustment may be required.
Blood pressure medications
Omega-3 may lower BP modestly.
Source: Clinical consensus
Orlistat (Alli)
Reduces fat absorption, including omega-3.
Source: FDA label
Stop 2 weeks before surgery
Bleeding risk from antiplatelet effect.
Educational information only. This is not medical advice. These statements have not been evaluated by the FDA. Talk to your prescriber before starting, stopping, or combining any supplement with prescription medication.