In 2008, professional chess grandmaster Vassily Ivanchuk lost a game, then was immediately asked to provide a urine sample for a drug test. Ivanchuk flipped out — he kicked a concrete pillar and pounded a cafeteria countertop — insulted that he would be asked to do something so demeaning after his loss. His fans and other players rallied to support him, the argument being that doping couldn’t help a chess player. Turns out those dopes were wrong.
I can honestly say I never expected the International chess tournaments players to fall under the World Anti-Doping Agency rules
source: https://www.inverse.com/article/27054-chess-performance-enhancing-drugs-doping-vassily-ivanchuk