Rashad Evans Says Jon Jones Tested Positive for Estrogen Blockers Prior to UFC 200

Former training partner Rashad Evans claims that Jon Jones tested positive for estrogen blockers in an out-of-competition test before UFC 200.

During a video segment as a correspondent for CBS Sports, the ex-Jackson-Wink MMA representative said a source within Albuquerque, N.M.-based camp informed him of the nature of Jones’ failed drug test. Evans did not name the substance or substances for which Jones tested positive. During a recent appearance on “The Herd,” UFC President Dana White said Jones tested positive for two banned substances.

Jones was pulled from the UFC 200 headliner against Daniel Cormier after USADA informed him of a potential anti-doping violation stemming from an out-of-competition drug test on June 16. In a press conference last Thursday, the interim light heavyweight champion denied using performance enhancing drugs but did not reveal the nature of his failed test.

Jones’ “B” sample was later tested and confirmed the findings of a “A” sample. USADA, which manages the UFC’s anti-doping cases, is not allowed to comment on the findings of the test. If Jones’ appeal is not successful, he will be facing a two-year suspension.

By themselves, estrogen blockers are not known as a PED, but certain types may increase testosterone production. They are also widely believed to be used to help an athlete come off of a “cycle” of PED use, both in terms of limiting the side effects and returning the body to its natural level of testosterone production. BloodyElbow.com has a more detailed explanation of the potential use of estrogen blockers here.

Retired UFC fighter Chael Sonnen backed up Evans’ assertion during a recent appearance on "The Joe Rogan Experience.” Sonnen, who lost to Jones in a light heavyweight title bout at UFC 159, previously tested positive for a pair of estrogen blockers, anastrozole and clomiphene, which he claimed helped him recover from testosterone replacement therapy. Sonnen was suspended for two years for failing a pair of drug tests in 2014.

Jones previously tested positive for cocaine prior to UFC 182 but wasn’t suspended because cocaine is not banned out-of-competition. The soon-to-be 29-year-old spent most of 2015 on the sidelines after being suspended and stripped of the 205-pound title for fleeing the scene of a hit-and-run accident in Albuquerque. “Bones” returned to the Octagon on April 23 at UFC 197, where he claimed the interim title with a five-round verdict over Ovince St. Preux.