It is illegal in most sports to take any of a list of banned performance-enhancing substances. There are governing bodies across sport to enforce these restrictions.
If an athlete were to honestly believe that they were taking such a substance, surreptitiously and in order to obtain an unfair advantage, but no such substance was present -- for example because an unscrupulous trainer believed the placebo effect would give them an advantage, or perhaps because their dealer is crooked -- would this fall foul of the regulations?
The reason I ask is that the violations which you here about concern the fact of consumption not the intent, which is clearly sufficient to sanction an athlete. Is this because intent doesn't enter into the fact of the offence, or because either the fact or the intent are sufficient?