If you are serious about your health, you probably buy the best natural products. And if you use fish oil, chances are you have come across advertising for "pharmaceutical grade fish oil" for about 10 times what you'd pay in the discount store.
There really isn't any national or international agency that has given its blessing to calling any brand of fish oil "pharmaceutical grade." In the USA, the United States Pharmacopoeia (USP) usually decides this sort of thing, and they simply have not made any pronouncements about fish oil.
That isn't to say that Dr. Sear's product isn't high-quality. It's just not "pharmaceutical grade." And there are brands like Xtend Life that sell an equivalent quality product for about half the price.
There is, however, a kind of fish oil that really is pharmaceutical grade. It's called Lovaza. It's fish oil without any impurities treated with alcohol to form a very stable product that won't go rancid in storage. It sells for about $240 for a 30-day supply.
And it's not as good for you body as either the Barry Sears or Xtend Life products, although your insurance company may pay for a $240 prescription fish oil while it won't pay for a $19.95 Xtend Life fish oil.
The problem with Lovaza is the way it's made. It's a fish oil ester. Fish oil esters don't break down in storage. They don't break down inside your digestive tract, either.
Up to 2/3 of a fish oil ester simply passes out your body with bowel movement. So you might think of it as a $720 a bottle product. You spend lots of money for no added protection.
You don't want to buy the really cheap fish oils that contain unidentified "marine liquids" (think, to put it nicely, "fish juice"). They can make you burp.
You aren't going to get added value from Lovaza. Actually you'll get less.
So the real choice is between the really good fish oil product that costs $39.95 and says it's pharmaceutical grade, only it isn't, and the really good fish oil product that doesn't make the claim and costs $19.95. Go with the product that doesn't need to make up a standard to say it's good.