CBD (Cannabidiol)

Medically reviewed by Prof. Giorgi Pkhakadze, MD, MPH, PhD — GMJ Editorial Board

What is CBD (Cannabidiol)?

Cannabidiol (CBD) is a naturally occurring compound found in Cannabis sativa plants, including both marijuana and hemp varieties. Unlike THC (tetrahydrocannabinol), CBD does not produce psychoactive effects or a “high.” CBD is one of over 100 cannabinoids identified in cannabis plants and has gained significant attention for its potential therapeutic properties.

CBD products are typically derived from hemp plants containing less than 0.3% THC, making them federally legal in the United States under the 2018 Farm Bill. The compound is available in various forms including oils, capsules, gummies, topicals, and isolates. Currently, there is no established Recommended Dietary Allowance (RDA) or Upper Limit (UL) for CBD, as it is not considered an essential nutrient.

Health benefits & uses

Strong evidence: The FDA has approved one CBD medication (Epidiolex) for treating specific forms of epilepsy, including Dravet syndrome and Lennox-Gastaut syndrome in patients 2 years and older. Clinical trials demonstrate significant reduction in seizure frequency.

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Moderate evidence: Research suggests CBD may help with anxiety disorders, with several studies showing anxiolytic effects in both animal models and human trials. Some evidence also supports its use for chronic pain management and sleep disorders, though more robust clinical trials are needed.

Limited evidence: Preliminary studies suggest potential benefits for inflammation, post-traumatic stress disorder (PTSD), substance abuse disorders, and certain neurodegenerative conditions. However, these applications require further research to establish efficacy and safety profiles.

How it works

CBD interacts with the body’s endocannabinoid system (ECS), a complex network of receptors, enzymes, and endogenous cannabinoids that help regulate various physiological processes including mood, pain perception, immune function, and sleep. Unlike THC, CBD does not directly bind to CB1 and CB2 receptors but instead modulates their activity indirectly.

CBD appears to work through multiple mechanisms, including inhibiting the enzyme that breaks down anandamide (a natural endocannabinoid), interacting with serotonin receptors, and influencing vanilloid receptors involved in pain and inflammation. It may also affect calcium channels and have antioxidant properties that contribute to its therapeutic effects.

Dosage

There is no standardized dosing for CBD, as optimal amounts vary based on individual factors, product type, and intended use. Typical adult ranges found in studies include:

General wellness: 5-25 mg daily
Anxiety: 25-75 mg daily
Sleep support: 25-160 mg before bedtime
Pain management: 2.5-20 mg daily, often combined with THC in clinical studies

The “start low, go slow” approach is recommended, beginning with 5-10 mg daily and gradually increasing until desired effects are achieved. Consultation with a healthcare provider is essential, especially for therapeutic applications or when taking other medications.

Food sources

CBD is not naturally found in conventional foods. The primary source is hemp-derived products specifically manufactured to contain CBD. These include:

CBD oils and tinctures, capsules and softgels, edibles such as gummies and chocolates, beverages infused with CBD, and topical products like creams and balms. Some hemp seeds and hemp seed oil contain trace amounts of CBD, but not in therapeutically relevant concentrations.

Safety & side effects

CBD is generally well-tolerated, with the World Health Organization stating it exhibits no potential for abuse or dependence. Common side effects are typically mild and may include drowsiness, dry mouth, reduced appetite, diarrhea, and fatigue.

More serious concerns include potential liver toxicity at high doses, as observed in some clinical trials. CBD can also affect blood levels of certain medications by inhibiting liver enzymes responsible for drug metabolism. Quality concerns exist in the unregulated market, with some products containing inaccurate CBD levels or contaminants.

Interactions

Drug interactions: CBD can significantly affect medications metabolized by cytochrome P450 enzymes, particularly CYP3A4 and CYP2D6. Notable interactions include blood thinners (warfarin), seizure medications, and certain heart medications. CBD may increase levels of these drugs, potentially causing adverse effects.

Supplement interactions: CBD may enhance the sedative effects of supplements like melatonin, valerian, or kava. It may also interact with St. John’s wort, which affects the same liver enzymes involved in CBD metabolism.

Who should be cautious

Pregnant and breastfeeding women should avoid CBD due to insufficient safety data. Individuals with liver disease should use CBD cautiously due to potential hepatotoxicity. Those taking prescription medications, particularly blood thinners or seizure medications, should consult healthcare providers before using CBD.

People with a history of substance abuse, while CBD itself is not addictive, should be aware that some CBD products may contain trace amounts of THC. Additionally, individuals operating heavy machinery should be cautious due to potential drowsiness effects.

Frequently asked questions

Will CBD show up on a drug test?

Pure CBD should not trigger a positive drug test, as most tests screen for THC. However, full-spectrum CBD products contain trace THC amounts that could potentially cause positive results with frequent use or high doses.

How long does it take for CBD to work?

Effects vary by delivery method. Sublingual oils typically work within 15-45 minutes, while edibles may take 30-120 minutes. Topical applications work locally within minutes, and effects generally last 2-6 hours depending on dosage and individual metabolism.

Is CBD legal everywhere?

Hemp-derived CBD containing less than 0.3% THC is federally legal in the US, but state laws vary. Some states have additional restrictions or requirements for CBD products. International laws differ significantly, so check local regulations when traveling.

Can I take CBD with other supplements?

Generally yes, but be cautious with sedating supplements as effects may be enhanced. Always inform healthcare providers about all supplements and medications you’re taking to avoid potential interactions.

What’s the difference between full-spectrum, broad-spectrum, and isolate CBD?

Full-spectrum contains all cannabis compounds including trace THC; broad-spectrum contains multiple compounds but no THC; isolate is pure CBD only. Full-spectrum may provide enhanced benefits through the “entourage effect,” while isolate eliminates THC exposure completely.