When it was announced that Brock Lesnar would be fighting at UFC 200 against Mark Hunt, the former heavyweight champion immediately became an active fighter in the eyes of USADA. While Lesnar was able to avoid the 4 month period of random drug testing prior to his UFC debut, he will now be subject to random testing until he officially announces his retirement.
Following his UFC 200 win over Hunt, Lesnar sounded as though he would be open to fighting in the Octagon again in the future.
In the wake of UFC 200, USADA spokesperson Ryan Madden informed MMAFighting that Lesnar will be subject to random testing until his official retirement:
“To my knowledge, Brock Lesnar has not notified USADA of his retirement from the UFC,” Madden said. “Therefore, he remains subject to USADA testing and the UFC anti-doping policy.”