On November 11, the WBC were told by VADA that Stiverne had tested positive on a drug test. It was said that the banned substance was methylhexaneamine, which is also known as dimethylamylamine or 'DMAA'. Povetkin's camp confirmed the fight will still go ahead. Stiverne claimed he ingested a post-workout supplement called SUPERPHARM without knowing it included dimethylamylamine, but under VADA’s rules an athlete is responsible for whatever goes into their body. The WBC took into account that it was Stiverne’s first offence when making its ruling and fined him $75,000. Just 20 hours before the fight was to take place, the WBC withdrew its sanction of the fight stating Povetkin had failed another drug test, this time for Ostarine. The test was taken of December 6. Stiverne later made a statement to tell everyone he will be heading home to Las Vegas and did not want to fight if the sanction was off, as that was the whole reason for him training and taking the fight in Russia. Following the cancellation, Stiverne's promoter Don King stated he would be filing a lawsuit against World of Boxing promoter Andrey Ryabinsky, just as Ryabinsky did against King when Lebedev pulled out of his scheduled rematch against Guillermo Jones, after Jones tested positive for a second time. At that time, Ryabinsky was awarded $1.6m in damages. On December 23, Ryabinsky stated that Povetkin's sample from December 13 came back negative. Ryabinsky claimed that the test where he had tested positive contained 0,00000000001g traces of ostarine and a previous random test in November also came back negative.