Sometimes there are contaminants in the fish oils, or they go rancid, but the maker is still selling them because they can’t afford to throw them out. Or maybe the amount claimed on the label is not really the amount inside the capsule. These are common things that unscrupulous companies are doing and it's awful for us consumers.
Whomever you choose to buy from though, make sure they share their tests, and make sure it’s an independent test, not one that the maker did on it.
I use a third-party lab on my supplements. I don’t personally test them because that would be a conflict of interest, right? But some makers boast their results. And then you later find out they were the ones testing the product!
Honestly, that doesn't help anyone.
DHA Script, on the other hand, is guaranteed to meet my high quality standards since it is made from carefully selected ingredients under very strict manufacturing processes and our brand of fish oil is sourced from clean water.
Recently, there were 30 fish oil brands (popular ones, too) tested by an independent lab and the average content of fatty acids varied by 24 percent. Worse, some products had less than 50% inside the softgel of the amount claimed on the label.
Contamination testing wasn’t so bad. Actually you might be worse off eating a fish that was caught in a dirty ocean than the purified fish oils. Most makers are okay on this or they are not testing for the impurities that they should be. I vet my labs.
I vet my sources. I openly post my Certificates of Analysis. This type of transparency is important to me and yet no other supplement maker I know of does this.
Doesn’t that make you wonder what they are hiding?
Maybe they don’t test their finished products! Ugh, that's terrible if they don't, as it's a total disservice to those who actually need this unique supplement.