Jones' doping violation a result of anti-estrogen substances

An attorney from the Nevada State Athletic Commission has confirmed that Jon Jones' recent doping violation was a result of the presence of two anti-estrogen substances, according to multiple reports.

The results were announced at an NSAC meeting on Monday.

Jones' positive test came to light on July 6, just three days before he was scheduled to fight Daniel Cormier in the main event of UFC 200 in Las Vegas.

The substances in question are hydroxyclomiphene (an anti-estrogonic agent) and letrozole metabolites (an aromatase inhibitor), per Steven Marrocco of MMAjunkie.

Marrocco also mentions that Jones has hired anti-doping attorney Howard Jacobs to represent him in his upcoming appeal. Jones is facing a potential two-year suspension from MMA competition.

The possibility of estrogen blockers was first raised by fellow fighters Rashad Evans and Chael Sonnen.

Evans reported the news on July 8, citing sources in Jones' camp, while Sonnen brought up the substances on "The Joe Rogan Experience" podcast on July 11.

Estrogen blockers are banned due to the role they can play in recovering from performance-enhancing drug use. Lowering estrogen levels can increase the body's production of testosterone, which tend to be low after a cycle of steroids.

On that same note, high levels of testosterone generated by PED use during the cycle can be converted into undesirable amounts of estrogen by aromatase, hence the need for aromatase inhibitors.

Jones has not been directly accused of using steroids and he and his team are expected to proceed with a full appeal.

Adam Hill of the Las Vegas Review-Journal reports that the commission unanimously voted to place Jones on temporary suspension until his case is resolved.