I am guessing USADA? Barao's first loss started with TJ, who was likely juicing himself. By the next time he fought TJ for the belt USADA was in and he started losing just about every fight. For the record, Weidman went from dominant to losing most every fight about the same time period as Barao.
I was wondering why speeds didn't respond to my post...then I realized I never submitted it lol...this is basically similar to what I was going to type.