Heavyweight Frank Mir applied for and received a therapeutic use exemption for testosterone replacement therapy prior to his May 26 bout in Las Vegas against UFC heavyweight champion Junior dos Santos.
Nevada State Athletic Commission executive director Keith Kizer confirmed a report on Friday that the state regulatory body approved Mir, 33, for an exemption because he exhibited "abnormally low" testosterone levels.
Mir and his representatives had no comment.
According to Kizer, Mir and the fighter's doctor informed the commission that the former UFC heavyweight champion began TRT treatments in early 2012. Kizer said Mir told the UFC in February that he was undergoing treatments for low testosterone. Mir first notified Kizer of his prescription on March 27 after he and five others scheduled to compete at UFC 146 were requested to undergo random drug tests that day in Las Vegas.
The March test nabbed Alistair Overeem with an elevated testosterone-to-epitestosterone ratio of 14:1. Mir's test came back clean, with an approximate T/E ratio of 1:1. NSAC standards allow for licensees to compete with a 6:1 ratio.
Overeem's abnormal levels cost him a chance to fight dos Santos at UFC 146 and resulted in a nine-month suspension by the commission. Mir (16-6), originally scheduled to fight Cain Velasquez, stepped in for the Dutch fighter but fell to dos Santos in a lopsided contest that ended in a second-round knockout.
Mir underwent two urine and five blood tests throughout the process, Kizer said, including the morning after his loss, which also was negative.