Cornholio is correct. The tests that we are talking about are confirmation tests. We tell the tester that we want to know how much of substance X (anavar) is in the sample. This tells us nothing about anything else that might also be in the sample. This is not as good as the GC/MS method used for doping control since it will not tell us, for instance, that the anavar we just tested also has a lot of winstrol in it.
BUT this test is much cheaper than a blind GC/MS. And if everyone is getting great results from, let's say, Bratis ox, but it only has 5 mg of ox per 10mg tablet, you can be sure you're getting ripped off! On the other hand, if it has 10, 12 or even more ox in it, then you can be pretty confident that it is not laced with anything else and you're getting your money's worth.
As far as testing every single bottle that each person orders, it makes much more sense to pool our resources and test a batch of each brand of ox from a particular supplier. I have a feeling a lot of you gals get your stuff from a few of the more reliable suppliers so sharing this info would be useful for many of you. This way we can test the BTG, tt, Bratis, Loeffler, etc from supplier X, Y, and Z and see if it's legit ox at a reasonable dose. If you're thinking about spending $250 on a bottle of ox, why not spend an extra $5 or $10 on contributing to getting it tested..........