The UFC partnered with USADA in 2015 as they sought to clean up the sport. They believed that this would help MMA enter the mainstream and achieve more respect. However, White didn’t practice what he preached. He knew about several occasions when fighters took steroids but didn’t act (via Clutchpoints).
Vitor Belfort infamously used PEDs before USADA’s introduction. He caused life-changing damage to several fighters but White didn’t intervene. However, the Brock Lesnar vs. Mark Hunt scandal was even worse. White allegedly supported this short-notice match-up even though Lesnar was on more juice than a racehorse.