It's no secret that Jon Jones was pulled from his UFC 200 main event rematch with Daniel Cormier for testing positive to a banned substance during a June 16, 2016, out-of-competition drug screen. What is a secret is what substance for which he tested positive.
The Untied States Anti-Doping Agency has a policy of not discussing such specifics unless an athlete has already publicly divulged such information. The UFC tends to follow suit.
Jones and his representatives held a press conference the morning after Jones was pulled from the fight, but declined to divulge what substance or substances for which he tested positive.
In the following days, two key mixed martial arts personalities, both veteran UFC fighters, have alleged that Jones tested positive for estrogen blockers.
Rashad Evans, while reporting for CBS Sports at UFC 200, said, “Jon Jones is out of UFC 200. He failed a drug test back in June… and it was due to estrogen blockers, I'm told by his camp.”
Following upon Evans' report, Chael Sonnen, during a recent episode of his Beyond the Fight podcast, was talking about the Jones situation, when he mentioned in passing, “Jon, who is popped for two banned substances, which are estrogen blockers, people are going to look at that and (go), ‘so.'”
Estrogen blockers are sometimes used medically to help men who have used testosterone supplements to help restore hormone balance, according to healthline.com.
There has been no further comment from any party confirming that the substance or substances that Jones tested positive for were estrogen blockers, and that likely won't happen until he and his representatives are further able to look into what caused the positive test result and has had a chance to appeal it to USADA.
“It's not that we're trying to hide anything or that we're not trying to get ahead of it and tell people what it is,” his manager, Malki Kawa, said in a Monday interview with the MMA Hour. “I'm going to stand by our comments at the press conference. Jon, at no point in time, was a cheater, has never cheated, has never taken any substance that he knowingly knew of that was on the banned list.”