Cannabidiol (CBD) is a type of cannabinoid, a chemical found naturally in cannabis plants. CBD doesn't cause the high feeling often associated with cannabis. That feeling is caused by tetrahydrocannabinol (THC), a different type of cannabinoid. Some people with chronic pain use topical CBD products, in an effort to avoid smoking or ingesting marijuana.
CBD might also widen blood vessels to improve blood flow. In a 2018 study on rats, scientists found that CBD helped reduce inflammation and protect against damage caused by arthritis . The researchers believe that CBD does this by reducing the production of inflammatory cytokines (chemicals that contribute to inflammation).