USADA (United States Anti-Doping Agency) testing numbers showed that Jon Jones was the most tested athlete followed by Jose Aldo and Yoel Romero. The UFC signed a deal with USADA back in 2015 for a comprehensive, year-round drug-testing program. Here's the list of athletes tested the most number of times by USADA Jon Jones - 62 Jose Aldo - 60 Yoel Romero - 58 Daniel Cormier - 57 Holly Holm - 55 Amanda Nunes - 54 Rafael Dos Anjos - 53 T.J. Dillashaw - 52 Donald Cerrone - 51 Paulo Costa - 50 Cris Cyborg - 50 Stipe Miocic - 49 Anderson Silva - 49 Conor McGregor - 48 Robbie Lawler - 47 Khabib Nurmagomedov - 47 Dustin Poirier - 47 Junior Dos Santos - 46 Edson Barboza - 45 Stephen Thompson - 45 Tyron Woodley - 45 Frankie Edgar - 44Sean O'Malley - 44Jimmie Rivera - 44Tecia Torres - 44Fabrício Werdum - 44Per the USADA database, the most samples submitted by UFC athletes all-time:J. Jones 62J. Aldo 60Y. Romero 58D. Cormier 57H. Holm 55A. Nunes 54R. Dos Anjos 53T.J. Dillashaw 52D. Cerrone 51P. Costa 50C. Cyborg 50S. Miocic 49A. Silva 49C.McGregor 481/2— Aaron Bronsteter (@aaronbronsteter) November 16, 2020R. Lawler 47Khabib 47D. Poirier 47J. Dos Santos 46E. Barboza 45S. Thompson 45T. Woodley 45F. Edgar/S. O'Malley/ J. Rivera/ T. Torres/F. Werdum 44— Aaron Bronsteter (@aaronbronsteter) November 16, 2020Jon Jones tested the most by USADAUSADA is considered by most as the world's leading anti-doping testing agency. There seems to be a correlation between fighters who tested positive for a banned substance and the number of tests done by USADA. Jose Aldo (L) punches Marlon Moraes in their bantamweight fight Jones has tested positive for banned substances in four separate occasions since 2015. The former Light Heavyweight champion tested positive for benzoylecgonine, the primary metabolite of cocaine, back in UFC 182. Since then Jones has tested positive for banned substances at UFC 200, 214 and then 232. Jose Aldo, the former UFC featherweight champion, has also had his tryst with USADA as per a story narrated by Joe Rogan on his podcast back in 2017: "The first time they [USADA] came [to Brazil] he wouldn’t do it, he wouldn’t take the test because he said he didn’t know the guy. So Aldo's guys, they’re trying to deport him [the sample collector], trying to kick him out of Brazil. "Like literally trying to get him out of there. Saying you don’t have any authority to test us, you’re not even from this country. They’re throwing the kitchen sink at him. Then finally the next day they get him [Aldo] to test. He does the test then he trips and spills it."Yoel Romero, TJ Dillashaw, Cris Cyborg and Sean O'Malley have all tested positive for banned substances in their career, and are among the most tested UFC athletes by USADA.