U.S. health authorities are signing off on human trials of CBD to treat opioid addiction.

The U.S. Food and Drug Administration gave the green light this week to Ananda Scientific to start human testing of its CBD drug Nantheia ATL5, the company announced.

The trials will be run out of UCLA and are funded by the U.S. National Institute on Drug Abuse.

The federal clearance for CBD opioid-addiction research “further re-enforces our vision of developing CBD as a therapeutic for a number of key indications.” Ananda Scientific CEO Sohail R. Zaidi said in a statement.

The clearance comes two years after the FDA issued a warning letter to Massachusetts-based Curaleaf for marketing its CBD product’s potential to treat opioid addiction. Curaleaf scrubbed its website, though national drugstore chain CVS Health dropped some Curaleaf products anyway.

Ananda Scientific is privately held and has offices in Los Angeles and Greenwood Village, Colorado. A company spokesman reached by Hemp Industry Daily did not immediately say where the CBD comes from or if it is naturally derived or synthetic.

The only plant-derived cannabinoid medicine approved for human use in the United States remains Epidiolex, a CBD drug that treats rare forms of epilepsy and is owned by Ireland’s Jazz Pharmaceuticals.

The National Football League and its players’ union have requested industry research on CBD and other cannabinoids for pain management.

The NFL says it is looking for information about “alternatives to opioids in routine pain management.” The request mentions CBD but is open to research on other cannabinoids.

The request issued Wednesday also mentions research on the “impact of cannabis or cannabinoids on athletic performance.”

The memo comes five months after the NFL Players Association updated its policy to discourage athletes from endorsing products that contain CBD or other cannabinoids.

The research is requested by March 31. The NFL asks submitters to label proprietary information and that no compensation is offered for the information.