The science on why some substances are permitted and others outlawed seems, well, a little unscientific, and the number of athletes granted drug exemptions must be troubling to those yearning for clean competition.
It's unfair to single out one among the scores of sportsmen and women whose medical information is emanating from Russia's cyberspace, but Bradley Wiggins' case is representative.
Before his Tour de France triumph in 2012, the Brit received intramuscular injections of a drug called triamcinolone, ostensibly to manage allergies. But that treatment was described by the Scottish Centre for Respiratory Research as "utterly bonkers".
Different doctors, of course, have different opinions, adding a level of subjectivity to the perplexity, so who do we trust?
For any fan thinking anti-doping agencies have it all figured out, let Maria Sharapova's suspension remind us how readily the demarcation shifts between exempt and illicit.
Her drug of choice, meldonium, was legal until the beginning of this year, catching out Sharapova a few weeks later. So which is right? Two thumbs up, like since its development in 1970, or a two-year ban, like since the start of 2016?
Judging by the number of athletes discovered using the drug for their apparently-dodgy tickers, the current status appears correct. But, by the same measure, couldn't Wiggins' hayfever medication one day creep from one side of the legal boundary to the other?
It's a dilemma that will only become worse as the stakes grow higher and the chemists more canny. But the performance-enhancing quandary extends well beyond newfangled designer drugs.
Consider cortisone, a steroid that suppresses pain and is about as common in a locker room as strapping tape, enabling athletes to overcome otherwise-debilitating injuries and perform in otherwise-impossible ways. Curiously enough, human growth hormone operates in a similar manner, aiding injury recovery and allowing our favourite athletes to return to action.
Neither cortisone nor HGH possesses proven performance-enhancing qualities. Both limit the impact of injuries. The use of one is banal, the other banned.
Moving from the lab into another wing of the hospital, further problems arise when assessing surgeries that spark greater achievement and are just as unnatural as pumping a bloodstream full of foreign chemicals.
Tiger Woods, once near-sighted enough to be declared legally blind, had Lasic eye surgery in 1999, proceeding with perfect vision to win 12 of his 14 majors.
In baseball, pitchers who sustained serious elbow injuries before 1974 saw their careers end but, since the advent of Tommy John surgery, can now repair the joint with a tendon harvested from elsewhere in the body and eventually throw better than ever.
That's the definition of performance-enhancing and is completely legal. Because who
would prevent an athlete laid low by a catastrophic injury from once more playing at their peak. Who would tell an asthmatic to put down the inhaler, tell someone stricken by allergies to sneeze it out?
More saliently, with all of these questions swirling in a cacophony of confusion, who would subject themselves to the thankless life of an anti-doping agent?