"Unlike their [Over-the-counter] OTC counterparts, prescription fish oil supplements are formulated to deliver high concentrations of DHA and EPA. Moreover, these compounds are delivered at doses proven to reduce triglyceride levels based on rigorous clinical trials overseen by the FDA."

"Research suggests that prescription formulas with higher levels of fatty acids called eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) can help to lower triglycerides (a blood lipid), prevent heart attack, and more."

"With DHA, you need to take around 600 milligrams (mg) per day to achieve a 20% drop in triglycerides. Lesser doses do little to alter triglyceride levels. OTC supplements only deliver 120 mg to 180 mg of DHA per dose (and perhaps less because supplements in the United States are not strictly regulated)."

OTC Effectiveness?

"The amount of DHA and EPA contained in any of the OTC supplements falls well short of the 'heart-healthy' claims made by manufacturers."

"OTC and prescription fish oil supplements contain more or less the same ingredients. But prescription supplements like Lovaza and Vascepa contain higher amounts of compounds DHA and EPA, known to promote heart health. ... Research has shown that the benefits of DHA and EPA are dose-dependent, meaning that better results are received at higher doses. And, until you reach a certain threshold, you may get no benefit at all."

Potential Side Effects?

"Large amounts of OTC supplements can add up to a prescription dose but would likely increase the risk of side effects." And what are the side effects? "The most common side effects are burping, indigestion, and altered taste."

Safe Amount?
"Common [Prescription] Dosage:  Typically 4 grams daily, often taken as four 1-gram capsules or two 2-gram capsules once or twice daily."

Most importantly, "studies suggest that doses of up to 10,000 mg [10g, which our dosage is nowhere near] per day may be safe for short-term use with no significant impact on blood clotting." [2]