I know nothing of boxing and MMA

edit: from an SI article...

"If so, Olympic wrestlers should be prime candidates for TRT, though it turns out that therapeutic-use exemptions are actually exceedingly rare when one has to petition the IOC rather than a state athletic commission for one. ("It's simply not done," according to Dr. Don Catlin, who sits on the IOC's review board for therapeutic-use exemptions, and who describes testosterone as the "preferred" performance-enhancing drug for elite athletes these days.)"
...

"Every sport struggles with performance-enhancing drugs of some stripe, but no other major professional sport offers its athletes this type of opportunity to use them right out in the open."