I was reading an article in ProCycling regarding the history of "Stimulants" in the Peloton. Looking at pictures of riders like Tom Simpson on the ground shaking in convulsions is frightening.
You'll never catch everyone, but I wish this level of drug enforcement was in place in other professional sports as well. Major League Baseball--for example-- is a sport where the average helmet sizes are increasing by up to seven sizes! (And I don't mean egos) The only way to increase the size of your head is with steroids. (Unless you're lifting weights with your eyebrows)