Is Optimum Nutrition Fish Oil Good? Nutrition, Benefits, and Honest Review

The strongest, most consistent finding in omega-3 research is that EPA and DHA lower triglycerides. A 2020 meta-analysis covering 23 studies and nearly 44,000 participants found that fish oil supplements reduce triglycerides by roughly 15%. The NIH Office of Dietary Supplements reports that each additional gram per day of long-chain omega-3s lowers triglycerides by about 5.9 mg/dL. That's real, and it's dose-dependent — more EPA+DHA produces a larger drop.

But here's where the marketing gets ahead of the science: lowering triglycerides does not automatically mean fewer heart attacks or strokes. Large randomized controlled trials — ASCEND with over 15,000 participants, ORIGIN with over 12,000 — tested standard-dose fish oil supplements and found no reduction in cardiovascular events. The one trial that did show a benefit, REDUCE-IT, used 4 grams per day of icosapent ethyl, a prescription-only, high-dose, EPA-only drug. That is not what you're buying in a standard fish oil softgel.

Observational studies consistently find that people who eat fatty fish have lower rates of cardiovascular disease. But that's dietary fish — a whole food that replaces less healthy protein sources and comes with selenium, vitamin D, and a different fatty acid profile. The supplement story is weaker, and the gap between 'lowers triglycerides' and 'prevents heart attacks' is where most fish oil marketing quietly glosses over the evidence.

Dietary fish provides omega-3s primarily in triglyceride form, which is the same form found in fresh fish and the form your body is designed to absorb. Most fish oil supplements, including Optimum Nutrition Fish Oil, use ethyl ester forms (created during processing) or re-esterified triglycerides. The absorption difference is modest — some studies suggest triglyceride-form omega-3s are about 30% more bioavailable than ethyl esters — but it's real. More importantly, eating fish doesn't cause fishy burps, because the omega-3s are embedded in a food matrix that digests differently than a concentrated oil capsule.

So when does a supplement make sense? If you don't eat fish at all — whether by preference, allergy, or dietary restriction — a fish oil or algae oil supplement is a reasonable way to get EPA and DHA. If you have elevated triglycerides and your doctor recommends a dose higher than diet alone can provide (2–4 g/day EPA+DHA), supplements become a practical necessity — you'd need to eat an impractically large amount of fish daily. But for the average person who eats fish a couple of times a week, a standard-dose supplement adds cost and potential GI side effects without clearly adding benefit.

The hierarchy is clear: dietary fatty fish first, concentrated supplements for therapeutic doses second, and standard low-dose softgels as a distant third — useful only if you can't or won't eat fish and don't need a high dose.