It is FDA-approved for treatment of high triglycerides (>500 mg/dl). In their marketing, they claim "Unlike LOVAZA, dietary supplements are not FDA approved to treat any disease." They also highlight the "patented five-step" purification process that eliminates any concerns over mercury or pesticide residues.
What does Lovaza cost? In Milwaukee, it costs about $70 per capsule per month (PCPM). Most people are taking four capsules per day: $280 per month, or $3360 per year to obtain 3360 mg of EPA + DHA per day. (Funny coincidence with the numbers.)
Did you catch that? $3360 per year, just for one person to take Lovaza.
What if I instead went to Costco and bought their high-potency fish oil. This is also an ethyl ester form. It costs $14.99 for 180 capsules, or $2.50 PCPM; each capsule contains 684 mg EPA + DHA. I would therefore have to take five capsules per day to obtain the same 3360 mg EPA + DHA per day. This would cost me 5 x $2.50 = $12.50 per month, or $150 per year.
$3360 per year vs. $150 per year to obtain the same dose of omega-3 fatty acids, or a 22.4-fold difference.