Still considered by many pundits as the greatest MMA fighter to ever live, former UFC middleweight champion Anderson Silva did enter a rough patch in the later years of his career. Not only did his KO loss to Chris Weidman mark the beginnning of his downfall and more losses were to come, but positive drug tests soon followed.
In 2015, Anderson’s win over Nick Diaz was overturned to a no contest once traces of the anabolic steroids Drostanolone and Androstane were found in his samples. Later on, in 2016, Silva was forced to pull out of his Kelvin Gastelum fight due to a second positive test, but in 2018, USADA exonerated the former champion, claiming contaminated substances were found in the samples then.