Cannabidiol (CBD)

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    Last Updated: March 5, 2025

    Like THC, CBD is a cannabinoid (a compound in cannabis). Unlike THC, CBD won’t get you high, but it shows promise as a treatment for epilepsy, anxiety, depression, pain, inflammation, cancer, and more. Unfortunately, as of 2022, human trials are still few.

    What is CBD?

    CBD (cannabidiol) is the second most abundant cannabinoid in cannabis, after THC (tetrahydrocannabinol).[4] Unlike THC, CBD won’t get you high; it’s typically used medicinally, not recreationally, with the four most commonly targeted conditions being pain, anxiety, depression, and sleep disorders.

    What are CBD’s main benefits?

    Human research on CBD has focused on two rare forms of epilepsy: Dravet syndrome and Lennox-Gastaut syndrome.[5] In humans and animals, CBD has shown promise as a treatment for a wide variety of ailments, notably anxiety,[6][7][8][9][10] depression,[8] pain,[11][12][13][14] inflammation,[15][16] and cancer.[17]

    Unlike cannabis and THC, CBD doesn’t impair coordination, judgment, or memory.[18] In a Critical Review Report published in 2018, the World Health Organization concluded that there was “no evidence of recreational use of CBD or any public health-related problems associated with the use of pure CBD".

    What are CBD’s main drawbacks?

    CBD’s adverse effects are usually minor, but they include lethargy, fatigue, sleepiness, fever, diarrhea, vomiting, decreased appetite, and increased levels of alanine aminotransferase (a marker of liver damage).[19][20][21]

    Other drawbacks include a paucity of human evidence, the unreliability of most CBD products on the market, and the “gray area” legality of CBD products.

    How does CBD work?

    CBD works in myriad ways, which are still being explored. For instance, it may reduce pain and stress via the TRPV1 receptor,[22][23][24] stress and depression via the 5HTI-alpha receptor,[25][26] and inflammation via the A2A receptors.[27]

    Unfortunately, CBD seems to work better in combination with THC.

    What are other names for Cannabidiol (CBD)?

    Note that Cannabidiol (CBD) is also known as:

    • Cannabidiol
    • Epidiolex
    • CBD

    Cannabidiol (CBD) should not be confused with:

    • THC
    • Cannabis
    • Sativex

    Dosage information

    The only CBD product approved in the U.S. is an epileptic drug: Epidiolex® is a solution (100 mg of CBD per milliliter) taken orally, preferably with food. The starting dosage is 2.5 mg per kilogram of body weight twice per day (so 5 mg/kg/day). The maximum dosage is 10 mg/kg twice per day (so 20 mg/kg/day). In people with hepatic impairment, the dosage is reduced.

    Since (i) dosages in studies are all over the place, (ii) a CBD product’s label will very often overstate or understate this product’s CBD content,[1][2] and (iii) high-fat and high-calorie meals can greatly increase CBD absorption,[3] properly dosing CBD products is very, very difficult.

    Frequently asked questions

    What is CBD?

    CBD, or cannabidiol, is the second most abundant cannabinoid in cannabis and is primarily used for medicinal purposes rather than recreationally. It does not produce a high like THC and is commonly used to address pain, anxiety, depression, and sleep disorders.

    CBD (cannabidiol) is the second most abundant cannabinoid in cannabis, after THC (tetrahydrocannabinol).[4] Unlike THC, CBD won’t get you high; it’s typically used medicinally, not recreationally, with the four most commonly targeted conditions being pain, anxiety, depression, and sleep disorders.

    What are CBD’s main benefits?

    CBD has shown potential benefits in treating rare forms of epilepsy — as well as various conditions such as anxiety, depression, pain, inflammation, and cancer — without impairing coordination, judgment, or memory. The World Health Organization has found no evidence of recreational use or public health issues related to pure CBD.

    Human research on CBD has focused on two rare forms of epilepsy: Dravet syndrome and Lennox-Gastaut syndrome.[5] In humans and animals, CBD has shown promise as a treatment for a wide variety of ailments, notably anxiety,[6][7][8][9][10] depression,[8] pain,[11][12][13][14] inflammation,[15][16] and cancer.[17]

    Unlike cannabis and THC, CBD doesn’t impair coordination, judgment, or memory.[18] In a Critical Review Report published in 2018, the World Health Organization concluded that there was “no evidence of recreational use of CBD or any public health-related problems associated with the use of pure CBD".

    What are CBD’s main drawbacks?

    CBD's main drawbacks include minor adverse effects such as lethargy, fatigue, and gastrointestinal issues, as well as a lack of substantial human evidence, unreliable product quality, and ambiguous legal status.

    CBD’s adverse effects are usually minor, but they include lethargy, fatigue, sleepiness, fever, diarrhea, vomiting, decreased appetite, and increased levels of alanine aminotransferase (a marker of liver damage).[19][20][21]

    Other drawbacks include a paucity of human evidence, the unreliability of most CBD products on the market, and the “gray area” legality of CBD products.

    What makes CBD products unreliable?
    Quick answer:

    CBD products are often unreliable because nonpharmaceutical versions can contain varying amounts of CBD and may include THC, as well as contaminants like metals, molds, and pesticides. The only FDA-approved CBD product, Epidiolex, is specifically used for 2 rare types of epilepsy.

    The only CBD pharmaceutical approved in the U.S. (Epidiolex®) is approved only for two rare types of epilepsy. Nonpharmaceutical CBD products are widely available, but they often contain a lot more or less CBD than stated on the label, and even sometimes some THC.[1][2]

    CBD products might also contain some of the same contaminants frequently found in cannabis: metals, molds, bacteria, pesticides, aflatoxins, synthetic cannabinoids,[29][30] and residual solvents from the production process (hexane, benzene, xylene, toluene, acetone, ethanol, and isopropyl alcohol).[31]

    What makes CBD evidence poor?
    Quick answer:

    The evidence for CBD is considered poor due to the limited number of human trials, which are often short in duration, and a reliance on animal studies that may not accurately reflect human responses. Additionally, there are concerns that CBD could potentially worsen certain types of cancer, which highlights the need for more comprehensive research.

    A 2019 review noted that human trials were few,[32] and they still are few in 2022. Most studies are in animals, and animal studies often translate poorly to humans[33] (CBD appears to be more bioavailable for rodents than for humans, notably[34]).

    Moreover, what human trials we have didn’t last very long,[35] so we don’t know much about the long-term effects of CBD. For example, like cannabis itself, CBD has been touted as a potential cancer treatment,[36] yet CBD-induced receptor activation could theoretically worsen certain types of cancer, such as colon cancer.[37]

    How does CBD work?

    CBD operates through various receptors; it potentially reduces pain and stress via the TRPV1 receptor, alleviates stress and depression through the 5HTI-alpha receptor, and addresses inflammation via the A2A receptors. Its effectiveness appears to be enhanced when it is used in combination with THC.

    CBD works in myriad ways, which are still being explored. For instance, it may reduce pain and stress via the TRPV1 receptor,[22][23][24] stress and depression via the 5HTI-alpha receptor,[25][26] and inflammation via the A2A receptors.[27]

    Unfortunately, CBD seems to work better in combination with THC.

    Research Breakdown