Former UFC fighter Ketlen Vieira’s difficult period with the PFL continues. She missed her chance to claim the belt against Cris Cyborg at PFL Tampa in August after missing the featherweight championship limit by 7.2 pounds. Now, the Brazilian fighter has again found herself in the spotlight after failing a doping test for the same fight.

According to a Sherdog report, Ketlen Vieira has been suspended for 6 months after failing a drug test conducted following her fight against Cris Cyborg. Mike Mazzulli, the director of the Mohegan Tribe Department of Athletic Regulation, which regulates the PFL’s anti-doping program, told the outlet that Vieira tested positive for a “steroidal substance” banned by the World Anti-Doping Agency (WADA).

Mazzulli didn’t disclose which particular substance the ex-UFC fighter tested positive for, but he confirmed that both her A and B samples showed adverse findings for the prohibited substance.

Soon after, Ketlen Vieira discussed her suspension with MMA Fighting. She disclosed that her doping violation was caused by medication she took to treat her knee injury right after being released by the UFC in May and before signing with the PFL in June.

“The thing is, throughout my time in the UFC, my team and I were always extremely careful with supplements and medical treatments to ensure there was never any risk of a test detecting a prohibited substance,” Vieira said. “In 10 years with the organization, there was never a single incident.

“However, after leaving the UFC and becoming a free agent, I had the opportunity to take a more comprehensive approach to my health and undergo medical treatment for a knee injury that I had been monitoring for a long time but that never fully healed due to the various medication restrictions I had to follow while competing in the UFC. So, my team and I took advantage of the fact that I had no active contract and focused heavily on treating my knee. I was able to take the necessary medications to help ensure the best possible recovery.”

Going by Vieira’s statement, it seems that she didn’t deliberately try to use any performance-enhancing substances. She explained that her positive test was the result of her long-running knee injury issues.

The Brazilian went through two notable knee injuries during her UFC run. In August 2018, the 35-year-old had to withdraw from her scheduled bout against Tonya Evinger because of a knee injury that required surgery. Five years later, she injured her knee once again before fighting Macy Chiasson. 

Vieira disclosed that she suffered the injury after one of her training partners landed a shot during training that caused a meniscus injury and fibula fracture. That time, however, the Amazonas native avoided surgery and recovered after three months of physical therapy. 

Reflecting further, Vieira explained that she didn’t expect the PFL to sign her while she was undergoing knee treatment and thought the medication traces would disappear before her fight against Cyborg. 

“What none of us expected, however, was to be surprised by the great news that I had been signed by the PFL,” she added. “As soon as we learned about the opportunity, we immediately discontinued all medications, but continued with non-medication treatments. To be completely honest, I believed that given the time between stopping the medications and my fight, there would be no possibility of any substance showing up in my tests.

“However, after the fight, we were informed that this had occurred. Despite what happened, we thank God that the knee treatment has produced good results. Since there was no intent to violate any rules on our part, the PFL decided to give me a six-month period to ensure everything is in order before my next fight.”

For her part, Ketlen Vieira maintained a clean record throughout her MMA career. Prior to her latest violation, UFC tested her 7 times from 2025 to 2026 and she never tested positive.

Vieira will be eligible to return to competition after her suspension ends on March 22, 2027. Nevertheless, her six-month suspension drew a quick reaction from her last opponent, Cris Cyborg, who thanked the PFL’s anti-doping agency for taking swift action.

Cris Cyborg reacts to Ketlen Vieira’s doping violation 

When it comes to doping violations, Cris Cyborg went through her own ordeal years ago. In 2011, the California Athletic Commission banned Cyborg after she tested positive for stanozolol metabolites following her victory against Hiroko Yamanaka in a Strikeforce featherweight championship bout.

The MMA legend attributed her violation to a dietary supplement. However, the commission turned her win into a no-contest, suspended Cyborg for one year and also imposed a $2,500 fine. Strikeforce subsequently stripped her of the featherweight title, marking one of the most controversial moments of her career.

After Vieira’s doping violation became public, Cyborg reminisced about her tough times with doping and thanked the PFL’s drug-testing program for protecting the integrity of the sport, while also sharing words of encouragement for her former opponent.

“I want to take a moment to thank Mike Mazzulli and the athletic commission for taking drug testing seriously and holding fighters to a high standard,” Cyborg wrote in a lengthy Instagram post. “My career has not been perfect, and I have never tried to hide from my past. In 2011, I had a positive test for a banned substance, served my suspension, accepted responsibility for what was in my body, and made major changes to the way I managed my team and supplements.

“Since then, I have competed under some of the most rigorous testing programs in MMA, including testing overseen by Mike Mazzulli, and I have continued to pass those tests. That is why I believe strict, independent testing is important. It protects the fighters, the sport, and the legacy we work our entire lives to build. I also want to give respect to Ketlen Vieira. She is a tough competitor, a fellow Brazilian and a former UFC title challenger.”

Ketlen Vieira’s doping violation won’t surprise fans, as it happens in the sport. However, the PFL’s decision to suspend one of its premier fighters shows that its drug-testing standards are just as strict as those of its competitor, the UFC.