Cannabidiol (CBD) oil is everywhere and seemingly in everything these days. It’s touted as a panacea for a massive range of illnesses and conditions, and even recommended as a daily supplement to help one smooth out the rough edges of life. CBD is one of the many chemical compounds called cannabinoids that is isolated from cannabis (marijuana). Cannabis contains over 400 chemicals including at least 120 cannabinoids, which are chemicals that stimulate cannabinoid receptors in the body. Yes, your body has cannabinoid receptors and you actually produce your own cannabinoids. The most well-studied cannabinoids that are isolated from cannabis are delta-9-tetrahydrocannabinol (THC) and CBD. CBD is not psychoactive like THC, and there are hundreds if not thousands of producers and products now on the market, sold everywhere from country markets to pet stores to pharmacies. Like most panaceas, the hype outpaces the evidence.

CBD and cannabinoids

CBD is an extract from cannabis leaves or flowers, typically dissolved in an edible oil. The extraction process and solvents used can dramatically affect the final product – from characteristics like taste and colour but also the CBD:THC ratio as well as other cannabinoid ingredients. Edible oils are a popular delivery form, especially for people seeking something more discreet than smoking or vaping. Edible oils can contain large amounts of CBD, and if the manufacturing is consistent and of high quality, doses should be predictable and reproducible from drop-to-drop and from bottle-to-bottle.

Regulation? It depends

Much of what I want to touch on in an examination of efficacy is grounded in an issue that I’ve repeatedly discussed on this blog in terms of natural products and supplements – the poor quality and consistency of products. Depending on where you live, CBD oil might only be available on the black or “grey” market which means there’s little consumers can rely on with respect to product quality and consistency. Without being assured that you’re purchasing a high quality product, it’s impossible for consumers to base expectations on published evidence. If you can’t trust what’s on the label of your CBD oil, then any published evidence, even if it’s of the highest quality, is largely irrelevant.

Studies in countries like the Netherlands have shown wide variations between label claims and actual ingredients, and the CBD:THC ratio is often if not invariably incorrect. However, in some countries like Canada, where cannabis has been legalized, licensed cannabis products sold by licensed producers and vendors must have independent validation of CBD and THC content, as well as verification of overall product quality. (If you’re interested you can see the label claims for products at the Ontario Cannabis Store.) Depending on where you live in the United States, your access to CBD and cannabis-based products varies at the state level, and it would be a blog post in itself to break this down. Even where it is technically illegal, CBD products may be widely accessible owing to lack of enforcement issues. Legality does not mean products are subject to any specific quality control specifications and regulations, and consumers interested in CBD oil will need to do their own homework, or consult a trusted health care provider. As with dietary supplements and herbal remedies, independent and verified testing by external organization is the gold standard for consumers seeking CBD oil.

Medical (prescription) products based on cannabis or that contain cannabinoids are available in many countries. Epidolex is an FDA-approved CBD extract that is approved for the treatment of seizures associated with Lennox-Gastaut syndrome or Dravet syndrome. There is also Marinol, which is a synthetic THC approved for nausea and vomiting associated with chemotherapy, and for the treatment of AIDS-related anorexia. There is also medical cannabis available based on medical authorization in many countries. While many expected the medical cannabis market to disappear with the legalization of cannabis, it continues to exists in countries like Canada.

The coexistence of CBD both in supplement form as well as in prescription form raises the question about whether or not CBD oil should be treated as a drug or as a supplement. As has been discussed on this blog repeatedly, drugs are typically considered unsafe and unproven until evidence shows otherwise. Regulators tend to take a different approach with supplements and “natural” products, generally assuming these products have long histories of use and are safe until evidence emerges to show otherwise. In countries like Canada where there are cannabis-based products available based on medical authorization and simultaneously via retail channels, sellers may be obtaining the same products from the same producers – they are just branded differently. Fortunately, for the sake of this post, whether it’s sold as a “drug” or as a “supplement” doesn’t matter – what is relevant is the evidence base.

Does CBD oil “work”?

I’ll cut to the chase and tell you that overall, the evidence for CBD oil isn’t impressive at all. There is something “there” for sure – CBD oil has pharmacological and drug-like effects. But the enormous enthusiasm is backed by very weak evidence, and the efficacy is well-established only for a few circumstances. Dravet syndrome and Lennox-Gastaut syndrome have been established as responsive to CBD. There are studies but a lack of convincing evidence for Parkinson’s disease and other movement disorders, schizophrenia, insomnia and anxiety disorders. Whether or not CBD is useful for treating chronic pain is unclear. When you have a licensed, regulated and quality controlled product, it’s probably safer than opiates, but there’s a lack of evidence to substantiate the grandiose claims made about the ability of CBD to be an effective pain control medication.

There is zero credible and convincing evidence to suggest that CBD is effective for serious conditions like treating cancer, or that routine use while well can prevent disease.

The risks

Substances that have pharmacological effects will also have side effects, and cannabinoids and CBD oil are no exception. Importantly, CBD oil can interfere with the effects of numerous prescription drugs owing to its effects on specific liver enzymes. Depending on the drug, levels can be raised or lowered, so anyone that takes prescription drugs must carefully verify the risk of drug interactions when CBD oil is consumed.

CBD oil seems to have a better side effect profile than THC-containing products, including cannabis, but the lack of robust study makes any itemization of side effects a challenge. Aggression/anger, irritability/agitation, and sleepiness have been reported with CBD products like Epidolex so they should be expected with CBD oil.

Conclusion: CBD isn’t a panacea

Every era has its preferred panacea, and CBD is what’s hot today. Indiscriminate and uncontrolled use may be what some consumers want, but it won’t answer questions about efficacy, long-term effects, or safety. Importantly, while it’s sold as a retail product, many consumers may be using it for medicinal purposes that are not supported by good evidence. While there are hundreds of clinical trials underway, the uncontrolled clinical trial in the consumer marketplace has also begun, and it won’t give us the answers we need anytime soon. At minimum, it’s important for consumers to be able to trust what’s on the label, and some jurisdictions have taken steps to ensure that consumers can at least have some confidence in what they’re buying. Time will tell if their confidence and enthusiasm in CBD is justified.

Images from flickr uses The Vape Guide and Mark used under a CC licence.


Posted by Scott Gavura