Anti-doping authorities like USADA, as well as sport federations, leagues and organizations around the world also find themselves in a difficult situation. These organizations must consider that clean athletes rely on anti-doping authorities to remove performance-enhancing drug use from sport, including those performance-enhancing drugs found in certain dietary supplements. However, they also recognize the dilemma facing athletes. It's not surprising that athletes turn to those who manage their anti-doping programs for direction about dietary supplements. After all, USADA provides a straightforward directory which allows individuals to find what medications are prohibited and which are not prohibited. (Global Drug Reference Online)
Why isn’t there similar advice for dietary supplements?
Unfortunately, the issue is complicated. Supplements are regulated differently than medications and the industry, as well as those who purchase supplements, think and act differently. As a result, it is impossible for any organization to say with 100% confidence, what substances a supplement contains. And when an athlete or consumer cannot be absolutely certain, what their supplement contains, the door is left open for two very real possibilities: