CBD

Also known as cannabidiol, hemp extract, cbd oil.

Last reviewed October 9, 2026 · Jump to references

What is CBD?

In plain words

CBD is a substance found in cannabis that does not cause the typical marijuana high. The liver breaks it down, and it can change how the body handles other medicines. Researchers study it for seizures, anxiety, pain, and sleep problems, with the strongest evidence supporting a prescription form for certain seizure disorders. CBD can cause side effects, including sleepiness and liver injury.

Technical definition

Cannabidiol (CBD) is a non-intoxicating, 21-carbon terpenophenolic cannabinoid found in Cannabis sativa; CBD oils and hemp extracts are mixtures rather than synonyms for the isolated compound. It has low affinity for cannabinoid receptors CB1 and CB2 and influences multiple signaling systems, including TRPV1 ion channels, although its therapeutic mechanisms are not fully established. In the United States, a purified prescription CBD medicine is FDA-approved for seizures associated with certain rare disorders, but commercial CBD oils are not equivalent approved medicines.

Educational information only. This page does not provide medical advice or determine whether a supplement is appropriate for you. Review supplements with a qualified healthcare professional, especially if you take medication, are pregnant, have surgery scheduled, or have a chronic medical condition.

Evidence by use

Each use is rated on its own. There is no single overall effectiveness score.