Just to be clear on what is considered doping, the WADA considers any substance (or method) to be on the prohibited list if it meets two of the following 3 criteria[1]:<p>- It has the potential to enhance or enhances sport performance
- It represents an actual or potential health risk to the athlete
- It violates the spirit of sport<p>So, in theory, the distinction of acceptable and non-acceptable is not drawn (only) in performance-enhancing drugs.<p>Another thing to consider is that (pre-BALCO) you are not always charged on taking performance-enhancing drugs but in either having some synthetic drugs on your organism detected or having some measurements over what is considered &quot;normal&quot; in humans. For example, T&#x2F;E higher than 4:1 ratio. This means that the ratio Testosterone&#x2F;Epitestosterone can be 4:1. If an athlete has a 1:1 level (which is normal), doping himself with testosterone won&#x27;t be considered positive as long as it&#x27;s kept below 4:1. All assuming that exogenous testosterone cannot be detected.<p>As far as I know, BALCO was the first time than some athletes were sanctioned without testing positive.<p>[1] <a href="http:&#x2F;&#x2F;www.usada.org&#x2F;substances&#x2F;prohibited-list&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www.usada.org&#x2F;substances&#x2F;prohibited-list&#x2F;</a>
[2] <a href="http:&#x2F;&#x2F;www.webmd.com&#x2F;fitness-exercise&#x2F;steroid-doping-questions-answers" rel="nofollow">http:&#x2F;&#x2F;www.webmd.com&#x2F;fitness-exercise&#x2F;steroid-doping-questio...</a>