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.


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.
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?

  2. Peter ZC St.Andy

    Yeah, the writer above is correct. It is a ridiculous argument that one of the aforementioned chemicals in marijuana is not useful because it needs to be given in a higher dosage.
    The idea here is clear. Money. It’s a foregone conclusion that each separate chemical in the marijuana plant has significant value on it’s own, but also as in pain medications, for example that have both a narcotic analgesic and Tylenol ( acetaminophen ) such as Percocet, oxycodone and acetaminophen, or the lesser strength-wise Norco (hydrocodone bitrate and 325 mg of acetaminophen, it goes without saying together those drugs have a much different effect albeit is much simpler, as the Percocet and Norco are prescribed many times so that they can act together as a acetaminophen can both help with very mild pain and also as a fever reducer. However, Tylenol also is administered especially too often with the two because doctors routinely have to write them for injuries, hospital stays etc.; when in reality higher doses of the two narcotic are not only better for the body singularly, as acetaminophen is quite bad on the liver, it also limits the intellectually wise approach of using the narcotic relievers on its on can be to rated to better relieve very short-term pain.
    That is a easy way of expressing what the writer was saying above. Since marijuana has so many chemicals that own it’s on could be a breakthrough such as we have seen in the specialized seizure drugs that scientifically have been used to the point of being miracle drugs for young children to the strains of strains of marijuana than have hundreds of chemicals many of which have been written off as “no real medicinal value.” Let’s hope that at some point doctors and scientist are free from the grip of lobbyists and special interests and begin practicing medicine again. It has been more than just greed that fouls up the medical trials leading to new discoveries just as much as foolish elected official help parts of law enforcement put pain doctors and internists even the occasional optomologists behind bars on such shameful abuses of their reach.
    So, in conclusion my point is there are many powerful forces turning doctors and researchers into any thing but…let’s hope the giant over-reaction ends on this war on doctors prescribing methods and what researchers choose to research so we can progress on into the next century as leaders in the medical field rather than the current state of very poor efforts from many if both, if those many, I believe the majority went into and still in their mind knows that the way medicine is practiced in 2016 is a drastic shrug of many great things that once seemed on the horizon.

Leave a Comment
