Testosterone replacement therapy was once regulated for use among fighters in the UFC. Among those that greatly benefited from it are now retired fighters Vitor Belfort and Dan Henderson, who had gotten a second wind in their careers upon taking TRT.
This procedure, however, was banned in 2014 following several controversies. But for fighters like Anderson Silva, TRT can actually be beneficial, as long as it is regulated by USADA.
“There are some athletes who need to make use of the hormonal replacement,” Silva said in an interview with Rap 77 (via MMAjunkie). “I think, if USADA regulated that, we’d have the sport at a high level, with athletes who have stopped fighting.