The FDA has finalized guidance on trials of human drugs containing cannabis and cannabis-derived compounds, offering updated direction on federally authorized sources for cannabis.

The National Institute on Drug Abuse’s (NIDA) Drug Supply Program (DSP), which provides cannabis grown under contract by the University of Mississippi, was formerly the only domestic, federally legal source for cannabis containing more than 0.3 percent delta-9 tetrahydrocannabinol (THC) for use in clinical research. But this has changed since the agency’s 2020 draft guidance, and sponsors and investigators now have multiple sourcing options.

According to the final guidance, researchers may now use non-NIDA DSP sources of cannabis that contain more than 0.3 percent delta-9 THC on a dry weight basis (a THC level that renders the cannabis a Schedule 1 controlled substance) as well as non-NIDA DSP sources for cannabis at or under the 0.3 percent threshold, so long as the FDA deems the source(s) to be of adequate quality. They may also still use the NIDA DSP for sourcing cannabis stronger than the 0.3 percent delta-9 THC threshold, the guidance says.

A list of growers of Schedule 1 cannabis cleared by the Drug Enforcement Administration (DEA) is located online and can be accessed through the guidance.