High-dose, highly-concentrated fish oil is known to lower triglycerides in people with elevated levels. One prescription product was even shown to lower the risk of cardiovascular events in such people. However, a clinical trial of another fish oil was recently stopped due to its low likelihood of providing this benefit. Learn how these products differ and how fish oil supplements compare to them in the Prescription Fish Oil vs. Supplements section of the Fish Oil Review. Also see our Top Picks for fish oil and other marine omega-3 supplements.