cannabidiol

cannabidiol (CBD), naturally occurring compound of the cannabis plants Cannabis sativa and C. indica. Cannabidiol (CBD) is one of numerous cannabinoid substances that have been identified in cannabis and is known for its nonpsychoactive properties, which differentiates it from tetrahydrocannabinol (THC), the primary psychoactive compound of marijuana. CBD is one of the main active substances of medical cannabis and can help prevent certain types of seizures. CBD is also suspected to be useful for the treatment of conditions such as anxiety, chronic pain, and insomnia, though scientific evidence remains limited.

CBD acts in part by reducing resting-state activity in multiple regions of the brain. This reduction potentially contributes to decreases in anxiety-related neural signaling and may help to normalize the activity of pain receptors, thereby decreasing pain sensations. The mechanism by which CBD exerts its effects, however, is not fully known. It appears to interact with various receptors, particularly some G protein-coupled receptors (GPCRs), such as serotonin receptors and cannabinoid (CB) receptors. At CB receptors, CBD acts indirectly, binding to a site that is adjacent to the receptor’s main active site. In doing so, CBD alters the ability of THC to bind to the receptors and thereby potentially impacts THC activity by both reducing psychoactive effects and enhancing side effects. CBD also has been found to dampen overactive neuronal stimulation by lysophosphatidylinositol, a molecule that plays a role in seizures.

The only CBD medication consisting of pure CBD that has been approved for use in humans is Epidiolex, which is an oral formulation prescribed for the treatment of certain seizure disorders. CBD, however, is widely available over the counter in various forms, including inhaled products; oils and tinctures taken sublingually (under the tongue); edible forms such as capsules, drinks, and gummies; and topical preparations, such as creams, balms, and lotions, which allow for localized use on the skin.

In general, CBD sold in over-the-counter products differs significantly in quality and quantity from CBD used in medicine and medical research. Some products labeled as CBD may not actually contain the substance as advertised, and many contain heavy metals and other harmful contaminants. Moreover, the legality of CBD products varies by country, state, and region, and products that are advertised as pure CBD may contain quantities of THC that render them illegal.

CBD generally is well tolerated. However, some individuals experience side effects, which can include diarrhea, dry mouth, drowsiness, changes in appetite and mood, nausea, and liver disease. CBD is known to interact with certain medications, particularly antidepressants, antiepileptic drugs, and anticoagulants such as warfarin. Studies in animals indicate that CBD is toxic to the male reproductive system and may harm the development of offspring born to mothers who are exposed to CBD during pregnancy.