The UFC and United States Anti-Doping Agency have made significant revisions to the promotion's anti-doping policy, according to Brett Okamoto of ESPN.
The promotion will now have a "UFC prohibited list" and "certified supplements," the latter offering immunity to athletes who test positive for a banned substance in the event those supplements are found to have been contaminated.
While the prohibited list reportedly follows World Anti-Doping Agency code, there are different thresholds for certain substances now that testing has advanced to the point where trace amounts can be detected. Additionally, an athlete who fails a test because of a contaminated supplement that's been certified by one of five independent supplement certifiers won't receive any discipline from UFC.