Former UFC Welterweight Champion Matt Serra recently revealed he uses testosterone replacement therapy (TRT).

“I’m on the TRT because I’m not competing anymore,” Serra said. “The TRT just shuts down the factory. I get my levels checked every six weeks. I go to a place. I’m not in a back alley going, ‘can I get a needle in my a**’. I got to a doctors. The take blood from me. They check my levels.

“It’s like the fountain of youth. There is a reason fighters shouldn’t be taking it. I got my testosterone checked, and it said I was low. So I started dragging my a**, and listen, the way I’ve been eating I should look way worse.”

Despite him personally using TRT, Serra says he understands why professional fighters should not be allowed to use it.

“For fighters, it’s an unfair advantage,” Serra said. “What the younger guys have is that athletism compared to the older guys, but the older guys have the experience. But now, you have these older guys who are taking the TRT who can have the athleticism of when the were younger plus the experience. That’s just not fair.”

Serra last fought in MMA in 2010. His career is highlighted by wins over Chris Lytle, Frank Trigg, and winning the UFC title from Georges St-Pierre.

Currently, Serra is a coach for UFC fighters such as Gian Villante, Aljamain Sterling, and former UFC Middleweight Champion Chris Weidman.