You can buy products containing cannabidiol (CBD) pretty much everywhere these days: health food stores, pharmacies, online retailers, supermarkets, and even gas stations.

Cannabidiol (CBD) is derived from the Cannabis sativa plant, which contains about 100 compounds called cannabinoids. Those include both CBD and its psychoactive cousin tetrahydrocannabinol (THC)—the psychoactive ingredient in marijuana that is responsible for the “high” feeling. Most CBD products come from a strain of Cannabis sativa plants, called hemp, that have less than 0.3 percent of THC, so there is no possibility for a high feeling. CBD attaches indirectly to cannabinoid receptors that are responsible for governing mood, appetite, pain, and inflammation.

Evidence-based uses

The scientific evidence is strongest for CBD’s effectiveness against childhood epileptic seizures. The first CBD-based medication approved by the U.S. Food and Drug Administration (FDA) is the epilepsy drug cannabidiol (Epidiolex). 

While poor funding has resulted in few robust research studies on CBD’s effectiveness, smaller-scale observational studies have suggested that it can help treat a variety of other conditions.

Anxiety. A study published in Neuropsychopharmacology in 2011 found that people with social anxiety disorder who took CBD before a public-speaking event reported feeling less anxiety and discomfort. A review of 49 studies published in Neurotherapeutics in 2015 also found evidence that strongly supported CBD as a treatment for generalized anxiety disorder, panic disorder, and post-traumatic stress disorder.

Researchers believe that CBD’s influence on serotonin receptors in the brain may be responsible for its beneficial effects against anxiety. Serotonin is a neurotransmitter that plays a role in mood, sleep, digestion, and behavior. CBD works similarly to selective serotonin reuptake inhibitors (SSRIs), a type of medication used to treat depression and anxiety by increasing levels of serotonin in the brain.

Insomnia. CBD activates the cannabinoid receptors in the brain, promoting a calming, sedative effect. According to a 2019 study published in The Permanente Journal, 67 percent of men and women with sleep problems who took CBD had improved sleep scores. CBD works best against insomnia that occurs due to anxious or worrisome thoughts that interfere with falling asleep at night.

Pain. CBD acts on receptors that mediate pain signaling and inflammation. In one small study published in Current Pharmaceutical Biotechnology, patients with peripheral neuropathy (nerve damage resulting in burning pain and numbness, typically in the hands and feet) applied a topical CBD oil or a placebo to their painful extremities for four weeks. Those using the CBD reported a significant reduction in intense pain. Other research suggests that CBD can ease pain caused by inflammation-related conditions, such as rheumatoid arthritis and fibromyalgia.

Parkinson’s disease (PD). CBD significantly reduced psychosis symptoms, such as hallucinations and delusions, in patients with PD, according to a study published in the Journal of Psychopharmacology.


CBD comes in different forms, such as gummies, topical creams, pills/capsules, and oils. The most common side effects are mild and include fatigue, drowsiness, diarrhea, dry mouth, and changes in appetite. The World Heath Organization notes that CBD does not lead to physical dependence.

Ingested CBD may interact with beta-blockers, statins, blood thinners such as warfarin (Coumadin), or other prescription drugs, so contact your doctor before taking CBD. As with any medication, it is always best to “start low and go slow” to determine the lowest effective dose. I usually suggest that patients start with 5 milligrams (mg) to 25 mg per day, depending on the patient and their symptoms. If the desired effect is not achieved, increasing the dose by about 5 mg every two to three days is advisable. While there is no ceiling on the daily dose of CBD, if one approaches 1,000 mg or more per day, it is best to do so only under the guidance of a physician who will watch for drug-drug interactions and liver function abnormalities.

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