[4][5] They are generally less preferred than statins, and use is not recommended by NHS Scotland as the evidence does not support a decreased risk of heart disease.

[3] In the European Union and other major markets outside the US, omega-3-acid ethyl esters are indicated for hypertriglyceridemia by itself, or in combination with a statin for people with mixed dyslipidemia.

[17] There appears to be little difference in effect between dietary supplement and prescription forms of omega−3 fatty acids as to ability to lower triglycerides, but the ethyl ester products work less well when taken on an empty stomach or with a low-fat meal.

Some producers also provide backward conversion of FAE to triglyceride form in assumption of its higher bioavailability, these products usually have 'rTG' in their names.

In people with CKD who require hemodialysis, there is a risk that vascular blockage due to clotting, may prevent dialysis therapy from being possible.

However, a Cochrane review in 2018 did not find clear evidence that omega−3 supplementation has any impact on the prevention of vascular blockage in people with CKD.

[3] In addition, as with other omega−3 fatty acids, taking omega-3-acid ethyl esters puts people who are on anticoagulants at risk for prolonged bleeding time.

[3][11] Side effects include stomach ache, burping, and a bad taste; some people on very high doses (8g/day) in clinical trials had atrial fibrillation.

[3] Omega-3-acid ethyl esters have not been tested in pregnant women and are rated pregnancy category C; it is excreted in breast milk and the effects on infants are not known.

The active ingredient is concentrated omega-3-acid ethyl esters that are made from fish body oils that are purified and esterified.

[24] In 2004, Pronova licensed the US and Puerto Rican rights to Reliant Therapeutics, whose business model was in-licensing of cardiovascular drugs.

[28] In 2009, generic companies Teva Pharmaceuticals and Par Pharmaceutical made clear their intentions to file Abbreviated New Drug Applications ("ANDAs") to bring generics to market, and in April 2009, Pronova sued them from infringing the key US patents covering Lovaza, US 5,656,667 (due to expire in April 2017), US 5,502,077 (exp March 2013).