Ketlen Vieira has been suspended six months after testing positive for a steroidal substance banned by the World Anti-Doping Agency following her Aug. 22 loss to Cris Cyborg in Tampa, Fla. Mike Mazzulli, director of the Mohegan Tribe Department of Athletic Regulation, told Sherdog that Vieira’s A and B samples from her in-competition collection produced the same adverse analytical finding. Mazzulli wouldn’t name the substance. He did confirm the suspension is retroactive to the date of the fight, which would put the end of it in late February 2027.
Vieira was notified of the positive result and provisionally suspended while she waited on the B sample analysis she requested. That sample matched. Representatives for Vieira, the PFL and the Florida Athletic Commission, which oversaw the event, didn’t respond to requests for comment, according to the Sherdog report, which Yahoo Sports also carried.
The Mohegan Tribe took over as the PFL’s anti-doping partner in 2025, replacing USADA. It previously ran Bellator’s testing program.
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This was already a weird fight before any lab got involved. It was booked as the first defense of Cyborg’s PFL women’s featherweight title, which she won late last year by beating Australian Sara Collins. Then Vieira missed weight by more than seven pounds. Cyborg made championship weight and kept the main event alive by agreeing to a non-title bout at 153 pounds. Vieira told MMAFighting.com that severe kidney and stomach pain before weigh-ins kept her from making the featherweight limit.
“I still accepted the fight and stepped into the cage knowing I would be giving up a significant physical advantage,” Cyborg said.
She won anyway, going five rounds against an opponent she described as noticeably strong. It was the 30th MMA win of her career, and the 41-year-old has now gone nearly eight years without a loss since Amanda Nunes took her UFC featherweight title. Cyborg called the circumstances around the bout “extremely unusual” and thanked the regulator. “I believe clean sport deserves strong enforcement,” she said. She also made a point of not piling on. “I have no interest in attacking her personally,” Cyborg said.
Cyborg addressed her own history, too, noting she tested positive for a banned substance in 2011, served the suspension and changed how she managed her team and supplements. She said she has passed testing under the strictest programs in the sport since, including ones overseen by Mazzulli.
Vieira arrived in the PFL after nearly a decade in the UFC, where she went 10-5 and spent her final four years alternating wins and losses. Her last Octagon appearance was a May decision win over Jacqueline Cavalcanti, after which her contract ran out and the UFC chose not to re-sign her. Three months later she was in Tampa trying to take a belt from the most decorated woman in the sport.
As for Cyborg, she felt good enough about the performance to rethink retirement. She plans two more MMA fights and one boxing match. The PFL holds the right to match any contract she signs, and once that window closes she can shop herself as an unrestricted free agent.
My take: anybody who had Vieira as a live dog in this one, and I’ll admit she looked like one on paper, should know she showed up seven-plus pounds over the limit and with a banned steroid in her system, and still lost to a 41-year-old across five rounds. The lab result tells you about Vieira. The scorecard tells you a lot more about Cyborg. Six months backdated to August is a light tab, too. Roughly seven weeks of it were gone before the public heard a word, so Vieira is free to compete again in late February.
