Cannabidiol (CBD) is well tolerated and widely used in the form of prescription Epidiolex® and sold over the counter and via the Internet nationwide. This cannabinoid is legal because it is produced in the low-tetrahydrocannabinol (THC)-producing hemp plant, for which cultivation became legal in 2018.  CBD facilitates various well-studied pharmacological effects on the body such as anxiety relief, anti-inflammation, neuroprotection, anti-psychosis, and anti-epilepsy. 
CBD provides a unique mechanism of action on multiple disease targets that have few other treatment options. Cannabidiol does not selectively act on one single receptor in the human body as many drugs do. The activity on multiple receptors allows a wide range of medicinal benefits, but also allows the potential for drug-drug interactions. 
Potential adverse interactions mainly occur in the liver where drugs are metabolized and detoxified by a group of enzymes called cytochrome enzymes. Negative side effects can occur if the same detoxifying enzyme is responsible for a multitude of drugs. Other drugs such as lorazepam and even common diet products like caffeine can have significant interactions with CBD in the liver.
Two of the most common adverse effects observed from CBD administration are drowsiness and sedation. 
Currently, CBD is taken by millions of people without prior evaluation of age, health, current medicinal conditions, genetic analysis, or current drug use. Because of the widespread use, thorough understanding of the adverse effects and potential toxicity of CBD is necessary. Even so, incidence of side effects is considered low and benign compared to conventional drug treatments.
One of the overarching concerns with CBD is the inconsistency with the products available online or in retail stores. Mislabeling, inaccurate concentrations, and impurities are a common risk that may lead to additional and unpredictable adverse effects.  Lastly, the dosage forms (i.e., capsules, tinctures, vapes, etc.) of CBD result in varying bioavailability in the body; this combined with the wide dosage range (~10mg–2,000mg) of CBD can result in potential adverse effects and toxicity. 
As the popularity of CBD increases, standardized methods of CBD production and analysis are sure to develop. Clinicians can evaluate the patient’s condition and medications to ensure maximum benefits and minimal side effects.
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