For example, one study found that only 31% of CBD products were accurately labeled; 43% contained more CBD than indicated on the label and 26% contained less than was indicated on the label. Moreover, THC (the main active component in marijuana) was found in 21% of the products. The only use of CBD generally recognized as safe and effective is treatment of certain seizure disorders. Three studies have shown that a pure CBD product, available by prescription only, reduces seizures in adults and children with 2 rare forms of epilepsy. In these studies, people were treated with the CBD product for 14 weeks while they continued to take other antiseizure medications. The CBD treatment decreased the numbers of seizures and reduced their frequency and severity. Research on other health claims for CBD include studies in people that have been small and/or of poor quality. In a small study, CBD seemed to reduce symptoms of anxiety and craving in abstinent people with heroin use disorder.
Another small study found that in people treated with antipsychotic medications for schizophrenia, CBD reduced symptoms of psychosis. Several retrospective and observational studies suggest that CBD might have beneficial effects in certain conditions, including pain, anxiety, sleep problems, and colitis. But other evidence suggests that these benefits are modest, at best, and these studies have important limitations (for example, inconsistent results for different studies, no comparison with a placebo). A mouth spray containing CBD may help treat spasticity in multiple sclerosis. CBD is probably safe to take by mouth or sprayed under the tongue. But CBD can have side effects, such as dry mouth, low blood pressure, diarrhea, decreased appetite, mood changes, light-headedness, and sleepiness. CBD can injure the liver, especially if it is not used under medical supervision. The contaminants in some CBD products could harm fetuses or infants, so CBD might not be safe for women who are pregnant or breastfeeding. People with liver disease who use CBD might need to take lower doses than healthy people.
High doses of CBD might make tremors and other unwanted movements worse in people with Parkinson disease. In studies in animals, CBD decreased sperm growth and development and reduced testicle size, so it might affect fertility in men. Some CBD products are contaminated with solvents, including some that can cause cancer, as well as pesticides, heavy metals, bacteria, and fungi. Some of these contaminants could be harmful to a fetus. CBD could speed up or slow down the body’s breakdown of certain medications and, therefore, decrease or increase levels of these medications in the body. Sedatives, such as benzodiazepines, phenobarbital, and morphine, as well as alcohol: CBD can cause sleepiness and drowsiness, so taking both CBD and sedatives might make people too drowsy.Sedatives, such as benzodiazepines, phenobarbital, and morphine, as well as alcohol: CBD can cause sleepiness and drowsiness, so taking both CBD and sedatives might make people too drowsy. Phenytoin and rifampin: may lower the levels of CBD.Phenytoin and rifampin: may lower the levels of CBD.
Levothyroxine, warfarin, and some antiseizure medications: CBD may increase blood levels of these medications, thereby intensifying and increasing their effects.Levothyroxine, warfarin, and some antiseizure medications: CBD may increase blood levels of these medications, thereby intensifying and increasing their effects. Valproic acid: Both valproic acid and CBD can cause liver injury, so the combination of CBD and valproic acid might increase the chance of liver injury.Valproic acid: Both valproic acid and CBD can cause liver injury, so the combination of CBD and valproic acid might increase the chance of liver injury. A pure CBD product, available by prescription only, reduces the number of seizures as well as their severity and frequency in adults and children taking other antiseizure medications for one of 2 rare forms of epilepsy. Other effects of CBD have not been confirmed in high-quality studies in people. CBD can have side effects, such as dry mouth, low blood pressure, diarrhea, decreased appetite, mood changes, light-headedness, and sleepiness. However, serious side effects are rare, and CBD is probably safe for most people. Pregnant and breastfeeding women and people with liver disease, Parkinson disease, and men who want to have children should not take CBD. Taking CBD while taking other medications that can cause drowsiness or while drinking alcohol can cause extreme drowsiness, which could be dangerous. People who take medications (including sedatives, antiseizure medications, some antidepressants, valproic acid, and medications to prevent the rejection of transplanted organs) should talk to their doctor before taking CBD.People who take medications (including sedatives, antiseizure medications, some antidepressants, valproic acid, and medications to prevent the rejection of transplanted organs) should talk to their doctor before taking CBD. The regulations about CBD are complicated and confusing. The following English-language resource may be useful. Please note that The Manual is not responsible for the content of this resource.
