This may help.
The flaxseed oil must…
Be made of 100% flaxseed: There should be no other flavors, additives, and especially no oils to prevent oxidation among the listed ingredients. (You want the oxidation in this case!) The only exception here is
if the label includes the words “flaxseed particulate†or “lignans.†Those are still part of the flaxseed, so they’re fine and still count as pure flax oil.
Require refrigeration, because it’s an omega-3 supplement and goes rancid quickly. If you buy a bottle of flax oil that doesn’t need to be refrigerated, you bought the wrong thing.
Be organic, because “you don’t want to burn toxic chemicals into your cookware to leach out forever more,†Canter writes.
Be unfiltered, although filtered is also probably fine: Canter doesn’t specify if the oil should be filtered or unfiltered. I’ve heard of people using both, and it worked fine. The bottle she links to in her post is
unfiltered, so that’s what I went with as well.
Be expensive: Well, it doesn’t have to be expensive, per se, but if you’re buying the right thing, it probably will be. Think around $17 or $20 for a 16-ounce bottle.
Between it flaking off and the cost, I don't use it any more.. Some swear by it.