Nate Diaz could have been on the mark here. If USADA and UFC wanted to catch cheaters, vs. looking like they want to catch cheaters, they would start using the carbon isotope ratio test. This almost guarantees that everyone using testosterone will be caught. There is no known way to get around this test. It is so good that the US chose not to adopt it for its Olympic athletes because "other countries weren't doing it", giving the floor to the assumption that all their guys would be booked, making other countries look cleaner. There are ways around even Olympic random testing, what makes anyone think UFC's anti-doping crew are infallible? You can't get guys who's training ritual is to "train all day" and not burn out. Steroids aren't used for the muscle mass, it's for the recovery, so that fighters can actually train all day and still have the energy and hormones to be an extravagant persona for the media. If the UFC adopted this test, it would be worse than Bellator Backyard Fighting. Everyone would drop like flies and you would be left with the skinny fat guys like the Diaz bros who can't keep a significant amount of muscle mass on due to the drop in testosterone and increase in cortisol that comes with training 5+ hours a day. You would get Overeem and Bigfoot level chins everywhere, and post-TRT Belfort-like performances. Fact of the matter is Nate is right. He was speechless after Conor accused his team of steroids, because he knows first hand how prominent PEDs are and hates it nonetheless, just didn't want to talk smack about his camp. tldr: If you told Dana White you had a testosterone use test that would catch everyone who's juiced in the past year(at least), and that you would be left with guys with the physique and lethargy of the Diaz bros what would he say?