Nate Diaz leans back at a post-fight podium, draws on a vape pen and casually tells reporters it is CBD oil for “the healing process and inflammation.” Moments like that helped turn a once-taboo topic into one of the most visible subplots in modern mixed martial arts: fighters who openly advocate for cannabis and say it has a legitimate place in their lives and careers.

Few stars embody that shift more than the Diaz brothers. Nick Diaz’s long, contentious history with regulators includes a 2015 five-year suspension from the Nevada State Athletic Commission—later reduced—after a marijuana-related test, a penalty widely criticized as excessive and out of step with evolving views on the plant. Instead of retreating, the Stockton veteran doubled down on his public support, frequently describing cannabis as part of how he manages anxiety and attention issues, most recently revisiting his suspensions in a 2024 docuseries.

Nate Diaz followed a different path, turning his infamous UFC 202 vape-pen moment into a business opportunity. After USADA opted for only a public warning, he became a high-profile pitchman for CBD products, telling media that cannabinoids helped his recovery before and after fights. The message resonated with fans who were already watching the wider wellness industry embrace CBD balms, tinctures and drinks.

If the Diaz brothers are the movement’s street-level heroes, the late Elias Theodorou became its policy trailblazer. The Canadian middleweight spent years battling for the right to use prescribed medical cannabis for chronic pain, ultimately securing the first recognized therapeutic use exemption (TUE) for in-competition medical cannabis from a North American regulator in 2020. His advocacy framed cannabis not as a shortcut, but as an alternative to opioids and other pharmaceuticals that carry serious side-effect and addiction risks.

Sean O’Malley, one of the UFC’s most marketable modern stars, added another wrinkle. Long open about using marijuana and discussing it candidily on his “Timbo Sugarshow” podcast, O’Malley often linked cannabis to creativity and relaxation. Ahead of a 2025 title rematch, he briefly quit weed in pursuit of marginal gains, only to lose again—fuel for fans who argued that cannabis wasn’t the problem. His journey has highlighted how fighters are openly experimenting with their own relationships to the plant rather than hiding it.

These voices are emerging alongside a growing, if still cautious, body of research. A landmark 2017 report from the National Academies of Sciences concluded there is “substantial evidence” that cannabis or cannabinoids can help reduce chronic pain in adults, while also warning of potential harms and calling for more rigorous study. Public-health agencies such as the U.S. Centers for Disease Control and Prevention stress that cannabis can impair coordination and reaction time, especially in high doses.

For many fighters, that nuance is exactly why they speak out. They argue that adults competing in one of the world’s most punishing sports should have access to cannabis-based options for pain, sleep and anxiety—within clear rules and with honest education for fans. Whether regulators fully catch up remains an open question, but in gyms, podcasts and post-fight scrums, the era of whispering about weed in MMA is over. The advocates are saying it out loud.