Belfort struggled in an interview to describe the cause of his low testosterone, other than to offer that he had felt rundown and tired. "It is like a dysfunction of the hormones, and it can cause your immune system to go down and it can cover a lot of things," he said. "If I don't do it [testosterone-replacement therapy], I am actually at a disadvantage. People don't know that."
Belfort referred questions regarding a more detailed explanation to medical professionals, including Pierce, medical director of the Ageless Forever clinic -- which sits five miles west of the Las Vegas Strip.
"Quite frankly, he has hypogonadism," Pierce said, hesitating initially. "Now why is that caused? I don't know. More than likely it is secondary to repetitive head trauma over the years."
Pierce issued a similar diagnosis about Mir on his TUE application to the Nevada commission, writing that he had a "history of head trauma ... inherent nature of his chosen career path is head trauma. Patient has had at least one loss of consciousness from head trauma."
Pierce said the most reasonable cause of low testosterone in a combat athlete, as well as a football player, is repetitive head injury resulting in damage to the hypothalamus or pituitary in the brain, which affects the release of natural testosterone. But "Outside the Lines" found no boxers having been granted a testosterone exemption -- in fact, Nevada officials said they had never received a request. And the NFL says it has granted a minuscule number over almost three decades.
To Pierce's point, researchers have documented pituitary dysfunction as result of head trauma in battered children, as well as victims of severe car accident and soldiers injured in war, but medical experts caution that in most cases individuals suffered an extreme injury, often accompanied by cerebral hemorrhage.
As for MMA fighters, medical experts question the logic of allowing someone diagnosed as suffering head trauma to step back in an MMA octagon. It would figure there'd also be some signs of cognitive problems. At the very least, a full CAT scan should be done to rule out permanent damage or anything catastrophic, they said.
Some experts further challenge the notion of head trauma triggering the shutdown or reduction of testosterone production in MMA fighters, noting that multiple hormones likely would be affected by damage to the hypothalamus or pituitary -- not just the production of testosterone.
Four endocrinologists and neuropathologists interviewed by "Outside the Lines" also said they were unaware of any controlled studies in which it had been shown head trauma in an athlete had shut down hormone production. The only definitive way to make such an observation is to autopsy brains after death, and an expert in the study of chronic traumatic encephalopathy in athletes indicated research to date had recorded no such hormone deficiencies.
"There doesn't appear to be any direct evidence from what I can see that that would be an answer for why they would have hypogonadism," said Dr. Ronald Hamilton, a Pittsburgh-based neuropathologist who has reviewed brain autopsies of former NFL players. "This kind of [hormonal] change has not been noted in autopsies of CTE patients."
Michael "The Count" Bisping probably knows best what a shot of testosterone can do, although by all accounts he hasn't dabbled in the stuff himself.