Oxford University Press's
Academic Insights for the Thinking World

Is CBD better than THC?: exploring compounds in marijuana

By Gary Wenk


Marijuana is the leafy material from Cannabis indica plant that is generally smoked. By weight, it typically contains 2%-5% delta-9 tetrahydrocannabinol (THC), the primary psychoactive agent. However the plant also contains about fifty other cannabinoid-based compounds, including cannabidiol (CBD).

One Internet ad claims that “cannabidiol (CBD) can cure arthritis, multiple sclerosis, chronic pain, schizophrenia, and epilepsy.” CBD is the main non-psychotropic cannabinoid present in the Cannabis sativa plant, constituting up to 40% of its extract. Somehow this one particular component of the marijuana plant has become much more popular than all of the sixty (at least) other biologically active molecules that have been isolated from this plant, to the point where growers are breeding marijuana plants with significantly higher levels of CBD.

750px-Marijuana

Why are people so excited about CBD? The answer lies in unpacking a series of complex truths, making distinctions between what is known and what is not known, and dispelling some false claims.

The human brain naturally possesses a pair of protein receptors that respond to endogenous marijuana-like chemicals. These receptors are incredibly common and are found throughout the human brain. When a person smokes marijuana, all of the various chemicals in the plant are inhaled, ultimately, into the brain where they find and bind to these receptors, similar to a key fitting into a lock. Which receptors are affected, and what parts of the brain are involved, differs for just about everyone, depending upon their genetic make-up, drug-taking history, and expectations regarding the experience; the last factor being commonly known as the placebo effect.

wenk figure
The images above come from Dr. Wenk’s research at Ohio State University, and demonstrate an increase in hippocampus neuron activity in rats following a cannabinoid treatment.
In addition, the chemicals inhaled into the brain also interact with a complex array of other neural systems; these interactions also contribute to the overall psychoactive experience, such as the marijuana’s ability to reduce anxiety, produce euphoria, or induce “the munchies.” My own research has demonstrated the positive effects of stimulation of the endogenous cannabinoid neural system in the aging brain.

Both CBD and THC are capable of interacting with this complex variety of proteins. However, and this is where things get interesting, they do not do so with the same degree of effectiveness. Scientists have shown that THC is over one thousand times more potent than is CBD, meaning a person would need to consume 1,000 “joints” of the genetically modified CDB-marijuana plant to get high. This chemical property of CBD has led to the accurate claim that CBD does not make one feel “high.” However, the low potency of CBD may also indicate that, by itself, it offers limited clinical benefits – currently- no one knows. Animal studies have discovered many beneficial effects of CBD but only when administered at very high doses.

What has become quite apparent is that no single component of the plant is entirely good or bad, therapeutic or harmful, or deserving of our complete attention. To date, all of the positive evidence supporting the use of medical marijuana in humans has come from studies of the entire plant or experimental investigations of THC. Given the very low potency of CBD within the brain it is highly unlikely that CBD alone will provide significant clinical benefit. Some small clinical trials are being initiated; until rigorous scientific studies are completed no one can claim that CBD is better than THC.

Gary L. Wenk, PhD., a Professor of Psychology & Neuroscience & Molecular Virology, Immunology and Medical Genetics at the Ohio State University and Medical Center, is a leading authority on the consequences of chronic brain inflammation and animal models of Alzheimer’s disease. He is also the author of Your Brain on Food: How Chemicals Control Your Thoughts and Feelings.

Subscribe to the OUPblog via email or RSS.
Subscribe to only health and medicine articles on the OUPblog via email or RSS.
Image Credit: First image is from United States Fish and Wildlife Service. Public Domain via Wikimedia Commons.

Recent Comments

  1. CBD Oil

    To say that one cannabinoid is better than another is a complete joke. It is only going to cause more divide in the community, and we need to stand united on all fronts to take back our rights to consume as we please to help our minds and bodies become healthy and whole again.

    Each patient is unique, and their is certainly a strain for each and every person out there. Now if these grimey politicians could just take their greedy little hands out of the Prison and Military complexes for 2 seconds to see that their energies, if focused in a positive and loving manner, would create so much life affirming energy we wouldn’t know what to do with it besides be happy.

    Can’t we all just get along?

Leave a Comment

Your email address will not be published. Required fields are marked *