Cannabidiol, or CBD, is the lesser-known child of the cannabis Sativa plant; its more famous sibling, tetrahydrocannabinol, or THC, is the active ingredient in pot that catapults users’ “high.” With roots in Central Asia, the plant is believed to have been first used medicinally — or for rituals — around 750 B.C., though there are other estimates too.

Cannabidiol and THC are just two of the plant’s more than 100 cannabinoids. THC is psychoactive, and CBD may or may not be, which is a matter of debate. THC can increase anxiety; it is not clear what effect CBD is having, if any, in reducing it. THC can lead to addiction and cravings; CBD is being studied to help those in recovery.

Cannabis containing 0.3 percent or less THC is hemp. Although last year’s Farm Bill legalized hemp under federal law, it also preserved the Food and Drug Administration’s oversight of products derived from cannabis.