Here is the US anti-doping agencies idea about taking supplements - basically they expect athletes to take zero supplements. Translate that, it means you will not be 100% of what you could be if you compete. This seems totally crazy - unless of course your actually goal is to faze out supplements as such & take them 'under the wing' of the big pharmaceutical companies ( a long term goal of those companies). Basically virtually all companies do not add illegal substances to supplements - where would be the profit in adding high price steroids to a fairly cheap (in comparison) product (which is what is implied). Truth be told most people who get caught with positive results are actually take innocent substances that cause unexpected false positives (like a cough medicine, or herbal preparations etc) they offer no performance boost at all. Anyone who isn't totally foolish can beat drug testing. Even a simple anti incontinence product taken a 12/24 hours before a test will stop most of the urine containments from leaving the kidneys (they only do urine, not blood testing), so anyone can pass a drug test. The only failures are the stupid or the innocent...but that's another story. Basically they US anti-doping agency is trying to hold athletes & supplement companies to ransom. If there is a need for extra tests to be done to products for them to be acceptable for athletes to use, then just say "these tests need to get done on your product", don't go with a blanket ban on all supplements & expect athletes to perform at peak efficiency, it's just not going to happen!