UFC interim champ Jon Jones positive for 2 estrogen blockers, receives temporary suspension

The Nevada State Athletic Commission today confirmed the substances for which Jon Jones tested positive prior to his ill-fated title unifier with light heavyweight champ Daniel Cormier at UFC 200.

Jones came back positive for hydroxy-clomiphene, “an anti-estrogenic agent” and “letrozole metabolite,” an “aromatase inhibitor,” NSAC attorney Caroline Bateman said today during a hearing in Las Vegas. The substances, which are both banned year-round by the World Anti-Doping Agency, are consistent with the type named by Jones’ ex-training partner and opponent, Rashad Evans, who first claimed the interim champ tested positive for estrogen blockers.

Estrogen blockers can potentially act in tandem with performance-enhancers by helping to mitigate their side effects, and are also thought to restart natural testosterone production.