Over the last few years, testosterone replacement therapy (TRT) has become one of the most controversial issues in MMA. In the time since Chael Sonnen originally popped for elevated testosterone at UFC 117, more and more UFC fighters have gotten aboard the TRT train. Most have faced heavy criticism for what fans perceived as a form of legalized cheating. With several years of use now past, let's take a look back at how fighters using TRT have fared at the highest levels of MMA competition.
Chael Sonnen (5-4)
The three-time title challenger is probably the most prolific TRT user in the UFC. Sonnen single-handedly brought TRT to the forefront of MMA discussion when he failed his UFC 117 post-fight drug test with a T:E ratio of 16:1 (well over the CSAC's legal limit). While that was when the news of his treatment first became public, during his suspension appeal process it was revealed that he'd been taking supplementary testosterone since 2008. So, throughout his UFC run, starting with the loss Demian Maia, he's been undergoing TRT.
Vitor Belfort (2-0)
The former Light Heavyweight champion has had a banner year in 2013. In just 6 months he's knocked out two Middleweight contenders with devastating, highlight reel headkicks. Unfortunately for Belfort, both wins have been marred by the cloud of his TRT use. His exemption was first confirmed* before his UFC On FX 7 fight against Bisping in Brazil. He was once again approved by the Brazilian commission at UFC On FX 8. His TRT use is particularly controversial as he failed a post-fight drug test for steroid use at Pride 32 in a losing effort against Dan Henderson.
*In his fight prior to FX 7, Belfort faced Jon Jones at UFC 152. Just before the event the acting commission confirmed that one fighter had applied and been approved for a TRT exemption, but never named the applicant. No other confirmed TRT recipient appeared on the card.
Dan Henderson (4-4)
Hendo been competing with the help of TRT longer than any other fighter in the UFC. He confirmed after the Sonnen fiasco that he's been receiving exemptions since his Pride days. Following the merger with the UFC, Henderson has gone an 8-4 with huge wins over the likes of Michael Bisping, Fedor Emelianenko, and Mauricio Rua. However, 4 of his 12 TRT fights were for the now defunct Strikeforce organization.
Quinton Jackson (0-2)
As the former Light heavyweight champ and one of very few UFC fighters to break the 1M PPV buyrate mark, Jackson was once one of the promotion's biggest stars. Following his UFC 135 title fight loss to Jon Jones he was all set to fight Ryan Bader in Japan. Then a knee-injury threw a wrench into his training plans and he was advised to undergo TRT as part his recovery. Both his fights while using TRT (the fight against Bader and his final UFC fight against Glover Teixeira) are widely regarded as among his worst performances.
Forrest Griffin (1-0)
Griffin had been the UFC's posterboy since his historic fight against Stephan Bonnar at the TUF 1 Finale. But after winning the 205 lb. strap years later, he'd gone a disappointing 3-2. Coming off the knock out loss to Shogun Rua, he picked up TRT while training for his rubber match against Tito Ortiz in what would become his final fight in the UFC.
Frank Mir (0-2)
Going into UFC 146, the former Heavyweight champ was riding an impressive three-fight win streak. Most recently, he'd broken the arm of Antonio Rodrigo Nogueira to defeat the Pride legend for the second time. He was set to face fellow former champ Cain Velasquez before Alistair Overeem's failed test got Mir promoted to contender status. Shortly after the news of Reem being pulled from the event, the NSAC confirmed that Mir would be competing with a TRT exemption for the first time in his career. He was knocked out by Junior Dos Santos in that fight and lost a one-sided decision to Daniel Cormier in his next Octagon appearance.
Todd Duffee (1-1)
Todd Duffee made a big impression with MMA fans in his UFC debut with a record 7 second knockout over Tim Hague at UFC 102. By his second UFC fight, he'd been granted a TUE by the NSAC. Despite dominating the first two rounds of his fight against Mike Russow, he was knocked out in the final round and subsequently cut from the promotion after some words with Dana White. He finally returned at UFC 155 and knocked out Philip De Fries in the first round.
Nate Marquardt (2-1)
Only days before UFC on Versus 6, in what was supposed to be his Welterweight debut, Marquardt was released from the UFC in probably the most surprising cut this side of Jon Fitch. In his previous bout against Dan Miller at UFC 128, he'd been granted a conditional exemption for TRT by the New Jersey commission. Marquardt was required by NJ to get his testosterone levels down to a certain point following the Miller fight. When he was unable to, the Pennsylvania commission refused to license him to fight Anthony Johnson. Having completely destroyed their main event for the show, the UFC cut him from the roster. it came out later that Marquardt had been on TRT since before his fight against Rousimar Palhares at UFC Fight Night 22. Following his release, he stopped his TRT treatment before returning to action in Strikeforce a year later.
Shane Roller (0-3)
The Lightweight sports the record for worst record of any UFC fighter using TRT. He began the treatment before his fight against Melvin Guard at UFC 132. He lost that fight by knockout in the first round and both his next two fights. He didn't pick up another UFC win until he dropped the treatment against doctor's orders in the face of fan criticism. In his first fight after halting TRT, he beat John Alessio by decision at UFC 148.
All told that puts the UFC record for TRT at 15-17 (1 N/A). Even if the numbers are adjusted to include Henderson's Strikeforce fights and assume the UFC 152 TUE was for Belfort, the record barely improves to 18-19. While this sub-.500 record doesn't strengthen TRT opponents' argument against it's inclusion in MMA competition, fighters wouldn't be going through the hassle if they didn't feel it had benefits.