Cannabidiol (CBD) is a

phytocannabinoid Cannabinoids () are several structural classes of compounds found in the cannabis plant primarily and most animal organisms (although insects lack such receptors) or as synthetic compounds. The most notable cannabinoid is the phytocannabinoid tet ...

discovered in 1940. It is one of 113 identified

cannabinoid Cannabinoids () are several structural classes of compounds found in the cannabis plant primarily and most animal organisms (although insects lack such receptors) or as synthetic compounds. The most notable cannabinoid is the phytocannabinoid tet ...

s in

cannabis ''Cannabis'' () is a genus of flowering plants in the family Cannabaceae. The number of species within the genus is disputed. Three species may be recognized: '' Cannabis sativa'', '' C. indica'', and '' C. ruderalis''. Alternativel ...

plants, along with

tetrahydrocannabinol Tetrahydrocannabinol (THC) is the principal psychoactive constituent of cannabis and one of at least 113 total cannabinoids identified on the plant. Although the chemical formula for THC (C21H30O2) describes multiple isomers, the term ''THC' ...

(THC), and accounts for up to 40% of the plant's extract. , clinical research on CBD included studies related to

anxiety Anxiety is an emotion which is characterized by an unpleasant state of inner turmoil Turmoil may refer to: * ''Turmoil'' (1984 video game), a 1984 video game released by Bug-Byte * ''Turmoil'' (2016 video game), a 2016 indie oil tycoon video ...

cognition Cognition refers to "the mental action or process of acquiring knowledge and understanding through thought, experience, and the senses". It encompasses all aspects of intellectual functions and processes such as: perception, attention, thoug ...

movement disorders Movement disorder refers to any clinical syndrome with either an excess of movement or a paucity of voluntary and involuntary movements, unrelated to weakness or spasticity Spasticity () is a feature of altered skeletal muscle performance with ...

, and pain, but there is insufficient high-quality evidence that cannabidiol is effective for these conditions. Nevertheless, CBD is an herbal

dietary supplement A dietary supplement is a manufactured product intended to supplement one's diet by taking a pill, capsule, tablet, powder, or liquid. A supplement can provide nutrients either extracted from food sources or that are synthetic in orde ...

promoted with unproven claims of particular therapeutic effects. The global market size for CBD was predicted to exceed billion by 2028. Cannabidiol can be taken internally in multiple ways, including by

inhaling Breathing (or ventilation) is the process of moving air into and from the lungs to facilitate gas exchange with the internal environment, mostly to flush out carbon dioxide and bring in oxygen. All aerobic creatures need oxygen for cellula ...

cannabis

smoke Smoke is a suspension of airborne particulates and gases emitted when a material undergoes combustion or pyrolysis, together with the quantity of air that is entrainment (engineering), entrained or otherwise mixed into the mass. It is commo ...

vapor In physics, a vapor (American English) or vapour (British English and Canadian English; see spelling differences) is a substance in the gas phase at a temperature lower than its critical temperature,R. H. Petrucci, W. S. Harwood, and F. G. H ...

oral The word oral may refer to: Relating to the mouth * Relating to the mouth, the first portion of the alimentary canal that primarily receives food and liquid **Oral administration of medicines ** Oral examination (also known as an oral exam or ora ...

, and as an

aerosol spray Aerosol spray is a type of dispensing system which creates an aerosol mist of liquid particles. It comprises a can or bottle that contains a payload, and a propellant under pressure. When the container's valve is opened, the payload is forced out ...

into the

cheek The cheeks ( la, buccae) constitute the area of the face below the eyes and between the nose and the left or right ear. "Buccal" means relating to the cheek. In humans, the region is innervated by the buccal nerve. The area between the insi ...

. It may be supplied as CBD oil containing only CBD as the active ingredient (excluding

HCor

terpene Terpenes () are a class of natural products consisting of compounds with the formula (C5H8)n for n > 1. Comprising more than 30,000 compounds, these unsaturated hydrocarbons are produced predominantly by plants, particularly conifers. Terpenes ar ...

s), CBD-dominant hemp

extract An extract is a substance made by extracting a part of a raw material, often by using a solvent such as ethanol, oil or water. Extracts may be sold as tinctures, absolutes or in powder form. The aromatic principles of many spices, nuts ...

oil, capsules, dried cannabis, or prescription liquid

solution Solution may refer to: * Solution (chemistry), a mixture where one substance is dissolved in another * Solution (equation), in mathematics ** Numerical solution, in numerical analysis, approximate solutions within specified error bounds * Solutio ...

. CBD does not have the same

psychoactivity A psychoactive drug, psychopharmaceutical, psychoactive agent or psychotropic drug is a chemical substance, that changes functions of the nervous system, and results in alterations in perception, mood, consciousness, cognition or behavior. Th ...

as THC, and can negate the psychoactive effects of THC on the body if both are present. However, in 2022 it was discovered that CBD heated to 250-300 °C (typically in e-cigarettes) may partially be converted into THC. , the

mechanism of action In pharmacology, the term mechanism of action (MOA) refers to the specific biochemical interaction through which a drug substance produces its pharmacological effect. A mechanism of action usually includes mention of the specific molecular tar ...

for its biological effects had not been determined. Unlike THC, which acts on the cannabinoid receptor type 1 (CB1) as a

partial agonist In pharmacology, partial agonists are drugs that bind to and activate a given receptor, but have only partial efficacy at the receptor relative to a full agonist. They may also be considered ligands which display both agonistic and antagonist ...

, CBD instead is a negative

allosteric modulator In pharmacology and biochemistry, allosteric modulators are a group of substances that bind to a receptor to change that receptor's response to stimulus. Some of them, like benzodiazepines, are drugs. The site that an allosteric modulator binds to ...

of CB1 receptors. In the United States, the cannabidiol drug Epidiolex was approved by the

Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a federal agency of the Department of Health and Human Services. The FDA is responsible for protecting and promoting public health through the control and supervision of food ...

in 2018 for the treatment of two

epilepsy Epilepsy is a group of non-communicable neurological disorders characterized by recurrent epileptic seizures. Epileptic seizures can vary from brief and nearly undetectable periods to long periods of vigorous shaking due to abnormal electrical ...

disorders. While the

2018 United States Farm Bill The 2018 farm bill or Agriculture Improvement Act of 2018 is an enacted United States farm bill that reauthorized $867 billion for many expenditures approved in the prior farm bill (the Agricultural Act of 2014). The bill was passed by the Senat ...

removed hemp and hemp extracts (including CBD) from the

Controlled Substances Act The Controlled Substances Act (CSA) is the statute establishing federal U.S. drug policy under which the manufacture, importation, possession, use, and distribution of certain substances is regulated. It was passed by the 91st United States ...

, the marketing and sale of CBD formulations for medical use or as an ingredient in dietary supplements or manufactured foods remains illegal under FDA regulation, .

Medical uses

''Cannabidiol'' is the generic name of the drug and its .

Research

, there was limited high-quality evidence for cannabidiol having a neurological effect in humans.

Epilepsy

In the United States, the FDA has

indicated In medicine, an indication is a valid reason to use a certain test, medication, procedure, or surgery. There can be multiple indications to use a procedure or medication. An indication can commonly be confused with the term diagnosis. A diagnosis ...

only one brand of prescription cannabidiol called Epidiolex for the treatment of seizures associated with Dravet syndrome, Lennox-Gastaut syndrome, or

tuberous sclerosis complex Tuberous sclerosis complex (TSC) is a rare multisystem autosomal dominant genetic disease that causes non-cancerous tumours to grow in the brain and on other vital organs such as the kidneys, heart, liver, eyes, lungs and skin. A combination ...

in people one year of age and older. While Epidiolex treatment is generally well tolerated, it is associated with minor adverse effects, such as

gastrointestinal upset Gastrointestinal diseases (abbrev. GI diseases or GI illnesses) refer to diseases involving the gastrointestinal tract, namely the oesophagus, stomach, small intestine, large intestine and rectum, and the accessory organs of digestion, the liver, ...

, decreased appetite, lethargy, sleepiness and poor sleep quality. In the European Union, cannabidiol (Epidyolex) is indicated for use as adjunctive therapy of seizures associated with Lennox Gastaut syndrome (LGS) or Dravet syndrome (DS), in conjunction with

clobazam Clobazam, sold under the brand names Frisium, Onfi and others, is a benzodiazepine class medication that was patented in 1968. Clobazam was first synthesized in 1966 and first published in 1969. Clobazam was originally marketed as an anxioselect ...

, for people two years of age and older. In 2020, the label for Epidiolex in the US was expanded to include seizures associated with tuberous sclerosis complex. Epidiolex/Epidyolex is the first prescription formulation of plant-derived cannabidiol approved by regulatory bodies in the US and Europe.

Other uses

Research on other uses for cannabidiol includes several

neurological Neurology (from el, νεῦρον (neûron), "string, nerve" and the suffix -logia, "study of") is the branch of medicine dealing with the diagnosis and treatment of all categories of conditions and disease involving the brain, the spinal c ...

disorders, but the findings have not been confirmed to establish such uses in clinical practice. In October 2019, the FDA issued an advisory warning that the effects of CBD during pregnancy or

breastfeeding Breastfeeding, or nursing, is the process by which human breast milk is fed to a child. Breast milk may be from the breast, or may be expressed by hand or pumped and fed to the infant. The World Health Organization (WHO) recommends that bre ...

are unknown, indicating that the safety, doses, interactions with other drugs or foods, and

side effect In medicine, a side effect is an effect, whether therapeutic or adverse, that is secondary to the one intended; although the term is predominantly employed to describe adverse effects, it can also apply to beneficial, but unintended, consequence ...

s of CBD are not clinically defined, and may pose a risk to the mother and infant. Many claims are made for the therapeutic benefit of cannabidiol that are not backed by sound evidence. Some claims, such as treatment of

cancer Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal bl ...

, are

pseudoscience Pseudoscience consists of statements, beliefs, or practices that claim to be both scientific and factual but are incompatible with the scientific method. Pseudoscience is often characterized by contradictory, exaggerated or unfals