What is CBD?
CBD is different from tetrahydrocannabinol (THC), the psychoactive chemical in cannabis that some people use to get high. CBD doesn't produce a high, and it's not addictive. "It doesn't get you stoned or woozy, and it doesn't affect driving," Dr. Grinspoon says.
It's not yet fully understood how CBD works to alleviate symptoms of various ailments. Our bodies make natural cannabinoids that help regulate sleep, appetite, and mood. It is believed that CBD from plants binds to CBD receptors in the body, and therefore may affect body systems.
How is CBD used?
People typically take CBD by mouth (such as a drop or two of oil placed under the tongue, or in pills or edible products like gummies) to help reduce symptoms of many conditions, including anxiety, bipolar disorder, arthritis, diabetes, a muscle disorder called dystonia, seizures, multiple sclerosis, Parkinson's disease, Crohn's disease, chronic pain, post-traumatic stress disorder, and insomnia.
CBD is also used in many other products: liquids that are vaporized and inhaled; creams that are rubbed onto aching joints; and cosmetics such as creams, lip balms, and even salt scrubs.
Does it work?
The National Institutes of Health (NIH) notes there is some evidence that CBD helps reduce pain, anxiety, and symptoms of psychotic conditions (such as schizophrenia). However, the NIH points out that we don't yet have enough evidence to prove that CBD reduces anything except epileptic seizures. Most evidence comes from studies with lab animals.
As we reported in March, the FDA recently approved the first marijuana-derived CBD (Epidolex) for the treatment of seizures associated with rare forms of epilepsy.
Is it safe?
While the World Health Organization maintains CBD is considered generally safe and well tolerated, it's not clear yet what quantity of CBD is safe and for how long.
According to NIH, CBD supplements in pill form have been used safely for six months in daily doses of up to 300 milligrams (mg), and for up to four weeks in daily pill doses of 1,200 to 1,500 mg. A 2.5-mg dose of CBD spray under the tongue has been used for up to two weeks safely.
These are some of the known risks:
Side effects. These can include diarrhea, upset stomach, nausea, fatigue, irritability, low blood pressure, lightheadedness, or drowsiness.
Medication interference. CBD can decrease or slow the way some medications are broken down in the body. "That means CBD may increase the levels of some medications in the blood," Dr. Grinspoon says. The big concern is with the blood thinner warfarin (Coumadin), but there are other medications that may be affected as well, including the heartburn drug omeprazole (Prilosec, Omesec) and the antidepressant amitriptyline (Elavil).