Jon Jones stunned the world in the run up to UFC 200 when it was revealed that he had given a positive test to USADA during his training for his fight with Daniel Cormier.
A rueful Dana White announced the news in a press conference, with Cormier having to take on Anderson Silva in little more than an exhibition bout as Jones faced up to a two-year suspension.
In the two weeks since the ban was announced, fans and the media alike have only been able to speculate as to what it was that caused Jones to test positive. Well, now we finally know.
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At the Nevada State Athletic Commission meeting yesterday, Jones' positive test was brought up as a talking point and the substances he took were revealed.
According to that meeting, Jones was taking an anti-estrogen substance.
"According to the NSAC's complaint, an out-of-competition sample provided by Jones on June 16 tested positive for clomiphene, which is listed as an anti-estrogenic substance on the banned list," according to ESPN.
He also tested positive for "traces of letrozole, an aromatase inhibitor, which works to prevent the synthesis of androgens such as testosterone into estrogen."
There could be two reasons for Jones taking these ant-estrogen substances:
1) He was taking testosterone and using the anti-estrogen drugs to combat one of the side effects of TRT, which is more estrogen in the body. And then there is 2) which is that it could be a potential masking agent athletes use to cover up a TRT (Testosterone Replacement Therapy) cycle.
Jones still maintains that he did not knowingly take any banned substances, but that defense won't help him when his suspension is handed down.