CBD for anxiety: dosage, benefits and side effects

Steve Silvestro, MD - Contributor Avatar

Written by Alison Dalton 

Steve Silvestro, MD - Contributor Avatar

Written by Alison Dalton 

last updated: Jun 08, 2021

4 min read

CBD is enjoying a huge surge in popularity. You can find it in everything from ice cream to face cream and bath bombs to dog treats. For those interested in taking it regularly for medicinal purposes, CBD is available in ingestible oils (sometimes called tinctures), alcohol tinctures, vaporization liquids, capsules, gummies, and topical ointments.

One of the most promising uses for CBD is in treating anxiety. But does it really work?


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What is CBD?

CBD stands for cannabidiol, a naturally occurring chemical found in the hemp plant, Cannabis sativa. The cannabis plant contains over 400 chemical compounds, of which approximately 80 are biologically active chemicals. The most important ones are about 60 cannabinoids (Meissner, 2021). One of them, THC, is psychoactive. CBD is a cannabinoid, but it’s not psychoactive. However, it appears to have other important properties.

How does CBD work?

Cannabinoids stimulate two receptors, cannabinoid receptor type 1 (CB1) and type 2 (CB2), in the endocannabinoid system (ECS). The ECS is a complex cell-signaling system that runs throughout the body. It plays a role in a wide range of activities: memory, movement, appetite, metabolism, crying, salivating, immunity, heart and lung functioning, and perception of pain (Sheikh, 2021).

We don’t know how exactly CBD works because the ECS is highly complex, and we still don’t entirely understand it. We do know that CBD can act through 65 separate, specific molecular targets, including 10 receptors, 32 enzymes, 10 ion channels, and 13 transporters (Sheikh, 2021). That means it can have a significant impact on a lot of areas of your body. 

OC CBD for anxiety: dosage, benefits and side effects image c22ca49a-3189-43de-ae80-53af7a202c5d

Can CBD help anxiety?

Anxiety disorders are the most common mental illnesses in the U.S. About 29% of people experience an anxiety-related disorder during their lifetime (Blessing, 2015).

Typically, anxiety disorders are treated with a wide variety of anxiolytic (anxiety-reducing) medications. These include serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), benzodiazepines, monoamine oxidase inhibitors (MAOIs), and tricyclic antidepressant drugs.

While these drugs help many people, they’re not effective in everyone, and they may not relieve all the symptoms of anxiety. They can also have side effects that make it difficult for people to tolerate their medications and stick with them. So an effective anxiety-reducing substance with few or no side effects would be a welcome addition to the medicine cabinet—and that’s where CBD comes in.

Although the first studies on the anxiety-relieving properties of CBD were done in 1974 and 1982, there still hasn’t been a major clinical trial of CBD for anxiety disorders (García-Gutiérrez, 2020). There have, however, been many small-scale trials on both animals and humans, and the results have been largely positive (Blessing, 2015; Shannon, 2019; Sheikh, 2021; Wright, 2020). It should be noted that most of these studies have been done on men; more studies on women are needed.

The studies have found that CBD can potentially relieve symptoms of several anxiety disorders, including generalized anxiety disorder, panic disorder, and social anxiety disorder. It may be effective for other mental illnesses, such as depression, post-traumatic stress disorder (PTSD), obsessive-compulsive disorder (OCD), and sleep disorders.

Unlike with some anti-anxiety medications, you can’t develop a tolerance to CBD, so you don’t need to continually up the dose for it to have an effect. CBD isn’t addictive and has no potential for abuse (WHO, 2017). It’s also safe at high doses, so you can’t overdose on it. That said, there has not yet been research into long-term use of CBD in humans (Bitencourt, 2018).

Legal, yes. The 2018 Farm Bill legalized the commerce of hemp and CBD products.

Regulated, no—and that’s a problem. The FDA hasn’t issued formal regulations for CBD manufacturing and has done very little random sampling of products on the market. As a result, many brands contain less CBD than they claim.

CBD products also may contain more THC than they should. The 2018 Farm Bill specified that CBD products can’t contain more than 0.3% THC. If they contain a greater percentage of THC, they’re considered marijuana, which is federally illegal (though legal in many states) and is psychoactive. Some studies have found that some CBD products contain more—sometimes much more—than the legal limit of THC (Lachenmeier, 2020; Bonn-Miller, 2017).

One study that tested 84 different CBD products found that CBD concentrations ranged from 0.10 mg/mL to 655.27 mg/mL—a huge range. Only about a third of these products were accurately labeled for CBD content. Vaporization liquids were the most frequently mislabeled, and oils were the most frequently accurately labeled (Bonn-Miller, 2017).

What are the side effects of CBD?

CBD is generally considered to have few side effects. Some users have reported side effects such as dry mouth, feeling high, change in appetite, fatigue, and drowsiness. These side effects may be due to contamination with THC (Lachenmeier, 2020). 

Types of CBD

CBD is available as CBD isolate, broad-spectrum CBD, or full-spectrum CBD.

  • CBD isolate is the purest form of CBD, devoid of the other chemicals found in hemp.

  • Broad-spectrum CBD has all the other chemicals found in the cannabis plant, except THC.

  • Full-spectrum CBD contains other natural chemicals found in the whole plant: various other cannabinoids (including THC), essential oils, and terpenes.

Because full-spectrum CBD can contain THC, which can cause anxiety, people with anxiety may want to avoid using that form.

CBD Dosing

Few studies have been done on the dosing of CBD, and because it isn’t regulated, a standard dose hasn’t been determined. In a 2018 study, male participants were given CBD before a simulated public speaking experience (an anxiety-producing experience for many of us). An oral dose of 300 mg of CBD, given 90 minutes before the test, effectively reduced the speakers’ anxiety. Those given a placebo, or CBD in 150 mg or 600 mg doses, had little benefit (Linares, 2019)

If you’re interested in CBD, talk to your healthcare provider about a good dose for you. When selecting a CBD product, make sure you choose a high-quality brand with a good reputation.


If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.

  • Bitencourt, R. M., & Takahashi, R. N. (2018). Cannabidiol as a therapeutic alternative for post-traumatic stress disorder: from bench research to confirmation in human trials. Frontiers in Neuroscience, 12 , 502. doi: 10.3389/fnins.2018.00502. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6066583/

  • Blessing, E. M., Steenkamp, M. M., Manzanares, J., & Marmar, C. R. (2015). Cannabidiol as a potential treatment for anxiety disorders. Neurotherapeutics: The Journal of the American Society for Experimental NeuroTherapeutics, 12 (4), 825–836. doi: 10.1007/s13311-015-0387-1. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4604171/

  • Bonn-Miller, M. O., Loflin, M., Thomas, B. F., Marcu, J. P., Hyke, T., & Vandrey, R. (2017). Labeling accuracy of cannabidiol extracts sold online. JAMA, 318 (17), 1708–1709. doi: 10.1001/jama.2017.11909. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5818782/

  • García-Gutiérrez, M. S., Navarrete, F., Gasparyan, A., Austrich-Olivares, A., Sala, F., & Manzanares, J. (2020). Cannabidiol: a potential new alternative for the treatment of anxiety, depression, and psychotic disorders. Biomolecules, 10 (11), 1575. doi: 10.3390/biom10111575. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7699613/

  • Lachenmeier, D. W., Habel, S., Fischer, B., Herbi, F., Zerbe, Y., Bock, V., et al. (2020). Are side effects of cannabidiol (CBD) products caused by tetrahydrocannabinol (THC) contamination? F1000Research, 8 , 1394. doi: 10.12688/f1000research.19931.3. Retrieved from https://pubmed.ncbi.nlm.nih.gov/32117565/

  • Linares, I. M., Zuardi, A. W., Pereira, L. C., Queiroz, R. H., Mechoulam, R., Guimarães, F. S., & Crippa, J. A. (2019). Cannabidiol presents an inverted U-shaped dose-response curve in a simulated public speaking test. Revista Brasileira De Psiquiatria (Sao Paulo, Brazil : 1999), 41 (1), 9–14. doi: 10.1590/1516-4446-2017-0015. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6781714/

  • Meissner H, Cascella M. (2021). Cannabidiol (CBD) [Updated 2021 Jan 16]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK556048/

  • Shannon, S., Lewis, N., Lee, H., & Hughes, S. (2019). Cannabidiol in anxiety and sleep: a large case series. The Permanente Journal, 23 , 18–041. doi: 10.7812/TPP/18-041. Retrieved from https://pubmed.ncbi.nlm.nih.gov/30624194/

  • Sheikh NK, Dua A. (2021). Cannabinoids. [Updated 2021 Apr 19]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK556062/

  • World Health Organization. (2017 Nov 6-10). Cannabidiol (CBD) Pre-Review Report - WHO. https://www.who.int/medicines/access/controlled-substances/5.2_CBD.pdf

  • Wright, M., Di Ciano, P., & Brands, B. (2020). Use of cannabidiol for the treatment of anxiety: a short synthesis of pre-clinical and clinical evidence. Cannabis and Cannabinoid Research, 5 (3), 191–196. doi: 10.1089/can.2019.0052. Retrieved from https://pubmed.ncbi.nlm.nih.gov/32923656/

How we reviewed this article

Every article on Health Guide goes through rigorous fact-checking by our team of medical reviewers. Our reviewers are trained medical professionals who ensure each article contains the most up-to-date information, and that medical details have been correctly interpreted by the writer.

Current version

June 08, 2021

Written by

Alison Dalton

Fact checked by

Steve Silvestro, MD

About the medical reviewer

Dr. Steve Silvestro is a board-certified pediatrician and Associate Director, Clinical Content & Education at Ro.