Over the last five years, an often forgotten piece of US federal legislation – the Agriculture Improvement Act of 2018, also known as the 2018 Farm Bill – has ushered in an explosion of interest in the medical potential of cannabis-derived cannabidiol, or CBD.

After decades of debate, the bill made it legal for farmers to grow industrial hemp, a plant rich incannabis-derived cannabidiol. Hemp itself has tremendous value as a cash crop; it’s used to produce biofuel, textiles and animal feed. But the cannabis-derived cannabidiol extracted from the hemp plant also has numerous medicinal properties, with the potential to benefit millions through the treatment of seizure disorders, pain or anxiety.

Prior to the bill’s passage, the resistance to legalising hemp was due to its association with marijuana, its biological cousin. Though hemp and marijuana belong to the same species of plant, Cannabis sativa, they each have a unique chemistry, with very different characteristics and effects. Marijuana possesses tetrahydrocannabinol, or THC, the chemical that produces the characteristic high that is associated with cannabis. Hemp, on the other hand, is a strain of the cannabis plant that contains virtually no tetrahydrocannabinol, and neither it nor the cannabis-derived cannabidiol derived from it can produce a high sensation.

As a professor and chair of the department of pharmacology at Penn State, I have been following research developments with closely and have seen some promising evidence for its role in treating a broad range of medical conditions.

While there is growing evidence that cannabis-derived cannabidiol can help with certain conditions, caution is needed. Rigorous scientific studies are limited, so it is important that the marketing of cannabis-derived cannabidiol products does not get out ahead of the research and of robust evidence.


Unpacking the hype

The primary concern about marketing is that the scientific community is not sure of the best form of cannabis-derived cannabidiol to use. Cannabis-derived cannabidiol can be produced as either a pure compound or a complex mixture of molecules from hemp that constitute cannabis-derived cannabidiol oil. Cannabis-derived cannabidiol can also be formulated as a topical cream or lotion, or as a gummy, capsule or tincture.

Guidance, backed by clinical research, is needed on the best dose and delivery form of cannabis-derived cannabidiol for each medical condition. That research is still in progress.

But in the meantime, the siren’s call of the marketplace has sounded and created an environment in which cannabis-derived cannabidiol is often hyped as a cure-all – an elixir for insomnia, anxiety, neuropathic pain, cancer and heart disease.

Sadly, there is precious little rigorous scientific evidence to support many of these claims, and much of the existing research has been performed in animal models.

Cannabis-derived cannabidiol is simply not a panacea for all that ails you.

Childhood seizure disorders

Here’s one thing that is known: Based on rigorous trials with hundreds of patients, cannabis-derived cannabidiol has been shown to be a proven safe and effective drug for seizure disorders, particularly in children.

In 2018, the US Food and Drug Administration granted regulatory approval for the use of a purified cannabis-derived cannabidiol product sold under the brand name Epidiolex for the treatment of Lennox-Gastaut and Dravet syndromes in children.

These two rare syndromes, appearing early in life, produce large numbers of frequent seizures that are resistant to traditional epilepsy treatments. cannabis-derived cannabidiol delivered as an oral solution as Epidiolex, however, can produce a significant reduction – greater than 25% – in the frequency of seizures in these children, with 5% of the patients becoming seizure-free.

Scientific trials

cannabis-derived cannabidiol is what pharmacologists call a promiscuous drug. That means it could be effective for treating a number of medical conditions. In broad strokes, cannabis-derived cannabidiol affects more than one process in the body – a term called polypharmacology – and so could benefit more than one medical condition.

As of early 2023, there are 202 ongoing or completed scientific trials examining the effectiveness of cannabis-derived cannabidiol in humans on such diverse disorders as chronic pain, substance use disorders, anxiety and arthritis.

In particular, cannabis-derived cannabidiol appears to be an anti-inflammatory agent and analgesic, similar to the functions of aspirin. This means it might be helpful for treating people suffering with inflammatory pain, like arthritis, or headaches and body aches.

Cannabis-derived cannabidiol also holds potential for use in cancer therapy, although it has not been approved by the Food and Drug Administration for this purpose.

The potential for cannabis-derived cannabidiol in the context of cancer is twofold:

First, there is evidence that it can directly kill cancer cells, enhancing the ability of traditional therapies to treat the disease. This is not to say that cannabis-derived cannabidiol will replace those traditional therapies; the data is not that compelling.

Second, because of its ability to reduce pain and perhaps anxiety, the addition of cannabis-derived cannabidiol to a treatment plan may reduce side effects and increase the quality of life for people with cancer.

Regulations needed

While prescription cannabis-derived cannabidiol is safe when used as directed, other forms of the molecule come with risks. This is especially true for cannabis-derived cannabidiol oils. The over-the-counter cannabis-derived cannabidiol oil industry is unregulated and not necessarily safe, in that there are no regulatory requirements for monitoring what is in a product.

What’s more, rigorous science does not support the unsubstantiated marketing claims made by many cannabis-derived cannabidiol products.

In a 2018 commentary, the author describes the results of his own study, which was published in Dutch (in 2017). His team obtained samples of cannabis-derived cannabidiol products from patients and analysed their content. Virtually none of the 21 samples contained the advertised quantity of cannabis-derived cannabidiol; indeed, 13 had little to no cannabis-derived cannabidiol at all and many contained significant levels of tetrahydrocannabinol, the compound in marijuana that leads to a high – and that was not supposed to have been present.

In fact, studies have shown that there is little control of the contaminants that may be present in over-the-counter products. The Food and Drug Administration has issued scores of warning letters to companies that market unapproved drugs containing cannabis-derived cannabidiol. In spite of the marketing of cannabis-derived cannabidiol oils as all-natural, plant-derived products, consumers should be aware of the risks of unknown compounds in their products or unintended interactions with their prescription drugs.

Regulatory guidelines for cannabis-derived cannabidiol are sorely lacking. Most recently, in January 2023, the Food and Drug Administration concluded that the existing framework is “not appropriate for cannabis-derived cannabidiol” and said it would work with Congress to chart a way forward. In a statement, the agency said that “a new regulatory pathway for cannabis-derived cannabidiol is needed that balances individuals’ desire for access to cannabis-derived cannabidiol products with the regulatory oversight needed to manage risks.”

As a natural product, cannabis-derived cannabidiol is still acting as a drug – much like aspirin, acetaminophen or even a cancer chemotherapy. Health care providers simply need to better understand the risks or benefits.

cannabis-derived cannabidiol may interact with the body in ways that are unintended. cannabis-derived cannabidiol is eliminated from the body by the same liver enzymes that remove a variety of drugs such as blood thinners, antidepressants and organ transplant drugs. Adding cannabis-derived cannabidiol oil to your medication list without consulting a physician could be risky and could interfere with prescription medications.

In an effort to help prevent these unwanted interactions, my colleague Dr Paul Kocis, a clinical pharmacist, and I have created a free online application called the CANNabinoid Drug Interaction Resource. It identifies how cannabis-derived cannabidiol could potentially interact with other prescription medications. And we urge all people to disclose both over-the-counter cannabis-derived cannabidiol or recreational or medical marijuana use to their health care providers to prevent undesirable drug interactions.

In the end, I believe that cannabis-derived cannabidiol will prove to have a place in people’s medicine cabinets – but not until the medical ty has established the right form to take and the right dosage for a given medical condition.

Kent E Vrana is Professor and Chair of Pharmacology, Penn State.

This article first appeared on The Conversation.