Yefimova beat the long course 50 m breaststroke world record at the Barcelona 2013 FINA World Championships, as well as winning the gold medal in the 50 m and 200 m breaststroke races at the same Championships. She held the world records in short course 50 m and 200 m breaststroke. But Yulia Efimova was reported to have failed a drug test. Her alleged positive test for DHEA, a prescription steroid banned in professional sports. On May 13, 2014 she was disqualified from October 31, 2013 till February 28, 2015. She was also stripped of her results and medals at the 2013 European Short Course Championships. Her world records are also invalidated.