Harvard Health Letter

In Brief: Prescription fish oil

In Brief

Prescription fish oil

With all of the over-the-counter fish oil that's for sale, why is there a prescription product? The FDA approved Omacor in 2004 to be used in conjunction with diet for treatment of high triglyceride levels (500 mg/dL or more). Fish oil is famed for its omega-3 fats, but in its natural state it's a mixture of other fats — including quite a bit of saturated fat — and triglycerides. The fish oil used to make Omacor has been chemically processed and purified so that it's close to being pure omega-3s (about 900 milligrams in total), although there's some vitamin E in there as an inactive ingredient.

In one study, people on special diets who took 4 grams of Omacor daily for four months reduced their triglyceride levels by 45%, although their LDL levels went up quite a bit. The statin drugs (Lipitor, Zocor, other brands) also pull down triglycerides, but are less effective in doing so when levels are very high. So Omacor fills a very specific need as a treatment for people with extraordinarily high levels of triglycerides. For most of us, one or two fish meals per week, or the over-the-counter fish-oil capsules, will provide an ample supply of omega-3 fats.

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