Nate Diaz may face a sanction from the U.S. Anti-Doping Agency (USADA) after vaping cannabidiol oil (CBD) during his postfight press conference Saturday, according to Marc Raimondi of MMAFighting.com.

"I can confirm that USADA is aware of the situation and is currently gathering information in order to determine the next appropriate steps," USADA spokesperson Ryan Madden said in a statement obtained by MMAFighting.com.

CBD is currently banned by the UFC and is one of 113 cannabinoids found in marijuana. However, unlike tetrahydrocannabinol (THC), the active ingredient in marijuana, CBD isn't psychoactive and is primarily used for pain relief, suppressing anxiety, depression, and nausea, as well as seizure prevention.

"It's CBD," Diaz said when asked about the pen. "It helps with the healing process and inflammation, stuff like that. So you want to get these for before and after the fights, training. It'll make your life a better place."

Diaz has never tested positive for substance use during his career. The 31-year-old lost by decision to Conor McGregor at UFC 202 on Saturday.