A recent Consumer Report Guide advises selecting supplements that carry the "USP verified" label. That means the nonprofit U.S. Pharmacopeia vouches for the "quality, purity, and potency of dietary supplement finished products, dietary supplement ingredients, and pharmaceutical ingredients."
In the report, here are some supplements that made the "good" list:
"--fish oil (The omega-3 fatty acids in fish oil, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), appear to be most effective at lowering triglycerides, an artery-clogging fat in the blood. ... Fish-oil supplements are probably safe for most people when taken in doses of 3 grams or less per day, though they might interact with certain drugs, notably blood thinners.)
--plant stanols and sterols (Those substances—which occur naturally in nuts, seeds, and whole grains—appear to reduce the amount of cholesterol the body absorbs from food. Manufacturers now add them to other foods, such as Benecol spread. Both are also available as supplements and can lower LDL cholesterol.)
--fiber (It's generally best to get fiber—which appears to lower LDL cholesterol, possibly by absorbing fat in the gut—from foods, such as beans, oats, produce, and whole grains. But certain fiber supplements, notably blond psyllium, might also help lower LDL.)"
***The Consumer Report Guide recommends seeing a doctor before taking any heart supplements!