I've updated/improved the Fish Oil Quality article to include more in-depth discussion of the term "pharmaceutical grade". This goes way beyond fish oil to arm against this very misleading marketing practice. As I point out in the article, the fish oil industry are the main culprits but many vitamin manufactures are joining the fray, claiming that their B vitamin, for instance is "pharmaceutical grade" which means it is 99% pure.
Not only is their no real meaning to the term there is not standard purity for pharmaceutical ingredients. Pharmaceutical ingredients are manufactured to purities appropriate for their use in drug preparations, i.e. the "requisite" purity.
Websters defines a pharmaceutical as a MEDICINAL DRUG. The USP is developing monographs for various dietary supplement ingredients that gives standards of purity and manufacturing required to bear the USP seal however most supplements claiming to be made with pharmaceutical grade ingredients neither have this seal or a monograph to start with. Even if they do it really has little to do with their "effectiveness" but only their manufacturing standards.