Cannabidiol (CBD) has received public interest as a medicine for pain, epilepsy, anxiety, and nausea. CBD refers to non-regulated oil that is either derived from a marijuana plant (true CBD oil) or a hemp plant (hemp oil).
The cannabis plant produces more than 100 cannabinoids. At least two of these, delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), have potential use for symptom management. THC is associated with central nervous system-altering effects; however, CBD oil is non-intoxicating at least in doses up to 600 mg. CBD-only products have garnered attention as a potentially safer therapy.
Some countries have legalized the use of CBD.
There are yet no convincing data that CBD is an opioid-sparing analgesic in humans. Three long-term perspective studies showed improved pain control, but neuro-psychiatric effects contributed to a discontinuation rate of 23%. A systematic review on THC/CBD did not show clinically significant benefits for neuropathic pain.
CBD appeared to reduce public-speaking-related anxiety and to decrease nausea. THC/CBD compounds have been studied in humans for insomnia with mixed effects. There is anecdotal evidence of CBD oil being used to treat refractory epilepsy in children and adults.

To date, no dose-confirming studies exist for pain, nausea, or anxiety. Dosages can range from 15 mg to 900 mg in various formulations, although many patients titrate to effect.

Most CBD formulations consist of viscous extracts suspended in oil, alcohol, or vaporization liquid that can be administered either orally (often under the tongue) or topically.
Side effects of CBD oil are mild and include nausea, dry mouth, dizziness, and drowsiness. The risk of drug interactions is not firmly established, although many experts suggest this risk would be low.

Is CBD addictive? Systematic reviews in humans are indecisive, although correlations have been noted between medical cannabis legalization and decreases in opioid overdose deaths.

While CBD oil may offer some therapeutic benefits, inconsistent labeling, an unknown therapeutic window, and a lack of quality human clinical investigations supporting its use should caution clinicians from recommending CBD oil to their patients.

See reference for more information.

Adapted from Christensen A, Pruskowski J. The role of cannabidiol in palliative care. Palliative Care Network of Wisconsin. Fast facts and concepts #370. Internet. Accessed on December 5, 2019.