New research contradicts prior claims and clarifies the interactions between the two main cannabinoids—Δ9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD)—when they are ingested orally as part of an edible cannabis product. The study’s findings suggest that CBD can inhibit the metabolism of Δ9-THC when the two are consumed together, leading to increased effects than when the same dose of Δ9-THC is consumed without CBD. The study, recently published in the journal JAMA Network Open, was led by researchers at Johns Hopkins University School of Medicine and partially funded by the National Center for Complementary and Integrative Health.

The use of cannabis edibles and oral formulations for therapeutic and nontherapeutic purposes has been growing. Products can contain varied amounts of Δ9-THC and CBD, but how these two cannabinoids interact after oral ingestion has been unclear. Prior research focused on cannabis products given by inhalation or intravenously instead of orally, and results have conflicted on the interactive effects of Δ9-THC and CBD. Existing data may not reflect what happens with cannabis edibles, which undergo initial metabolism in the intestine and liver before reaching the body’s systemic circulation.

 Read the full research result