I've been asked several times recently about CBD oil for pain relief. (In short, CBD oil is cannabidiol oil derived from cannabis plants and is purported to have pain relieving benefits without the high provided by the component THC also found in the plant.) I have searched all of my resources and will try to synthesize here for you what I have found. I'll first provide a little background on how we might view CBD oil from the lens of Chinese medicine, then summarize theories on the chemistry and physiology of how it works from a western perspective and the existing research. The short answer though, and what I will often be heard saying, is that what is right for one person may not be right for another. In chronic pain management, there are no panaceas. No one trick that works for every pain patient. There is only a big bag of tools that a good provider can pick and choose from tailored to your specific condition and constitution. Pain is an important signal that something is wrong and needs help. Analgesics suppress that pain. As a chronic pain patient and practitioner, I'm acutely aware of the necessity for relief. I'm also aware of the need to continue addressing the underlying conditions that are contributing to the pain.
This blog post is focused on CBD oil used topically for chronic pain relief. Research exists on the use of cannabis in general for cancer pain, cancer nausea and vomiting, and a variety of other conditions. The research looks at oral ingestion of THC/CBD blends, THC, oromucosal sprays, and smoking cannabis. The field is large and resources are fairly easy to find on these forms of cannabis usage. CBD oil used topically has not be thoroughly researched and finding peer-reviewed studies on its use for chronic pain is difficult. The information in this blog should not be construed as an endorsement of CBD oil or any specific product. My intention is simply to provide a summary of the information available.
It is difficult to call CBD oil a natural approach to pain relief, unless it is in tincture form or an oil based infusion that does not isolate CBD. Like any plant derived constituent used in western pharmacology, CBD is an isolated chemical component that naturally exists in a synergistic relationship with often thousands of other components. In other words, CBD oil takes a single component and uses it in isolation when it normally exists and is normally consumed in concert with many other components. In natural medicine we are usually using a whole plant or part of a plant (such as a flower bud or the bark of cinnamon) rather than one single constituent. We see the greatest benefit from the unique relationship of that component to all the other components that make up that plant. We are rarely using a synthetically derived or lab separated chemical component of the plant. This is very difficult in terms of research though as it is hard to separate out confounding variables when you are using thousands of components vs one constituent. (Clearly pro-cannabis, but to the point of whole plant vs. derivatives, Project CBD is a resource. https://www.projectcbd.org/article/cbd-misconceptions. They also discuss foods that naturally stimulate receptors involved in the mechanisms thought to explain how marijuana can reduce pain.) It appears that some oils are created by soaking the plant in oil, which would entail minimal processing and, most likely, wouldn't isolate the CBD oil from the THC.
When we use plants in natural medicine, we are looking at all aspects of the plant and its life world. We like to look at where the plant naturally grows, what seasons it thrives in, what it grows with, how vigorous it grows, the shape of the plant as it grows, etc. etc. In short, it's actually very difficult to find information from a Chinese medicine perspective on just CBD vs. marijuana in general. (For a sample of our view on marijuana, here is a great article by one of my teacher's teachers http://www.acupuncturetoday.com/mpacms/at/article.php?id=33026.) The marijuana plant is a hearty plant that grows wild in regions where it hasn't been planted in centuries. For example, the seed of the plant (ma zi) is used in a popular formula for constipation (ma zi ren wan). Ma fen is also listed in the materia medica and may be the seed plus the outer shell (pericarp) of the seed.
Ma zi is considered sweet in flavor and neutral in temperature. Ma fen, on the other hand, is considered acrid in flavor and toxic indicating that different parts of the plant have different properties and different indications for their usage. It is this temperature and flavor information that helps me determine whether hemp seed would be good for you or not. If you are a person with lots of phlegm for instance, I might not want you to have this formula. Or, I might modify the formula it is in so that your phlegm is also addressed and not worsened. There is no information in the chinese materia medica (our encyclopedia of plants, minerals, animals) on the leaves or roots of the cannabis plant. And, of course, there is no information on CBD in isolation.
From a western perspective, research has been undertaken to understand how cannabis interacts with the body. This is largely from an ingested or smoked application. The theory is that the body has an endogenous (natural, internal) cannabinoid system made up of receptors for cannabinoids that occur in various plants and foods. When a receptor comes into contact with a cannabinoid, the body creates a complex conversation of signals that may create analgesic reactions (pain relieving). An example of a more detailed understanding of the interaction: "In 1988, the first cannabinoid receptor was identified (CB1) (Howlett et al 1988) and in 1993, a second was described (CB2) (Munro et al 1993). Both are 7-domain G-protein coupled receptors affecting cyclic-AMP, but CB1 is more pervasive throughout the body, with particular predilection to nociceptive areas of the central nervous system and spinal cord (Herkenham et al 1990; Hohmann et al 1999), as well as the peripheral nervous system (Fox et al 2001; Dogrul et al 2003) wherein synergy of activity between peripheral and central cannabinoid receptor function has been demonstrated (Dogrul et al 2003). CB2, while commonly reported as confined to lymphoid and immune tissues, is also proving to be an important mediator for suppressing both pain and inflammatory processes (Mackie 2006)." (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2503660/)
Research suggests that cannabis in general can provide relief from cancer related pain, nausea and vomiting. These studies have not addressed topical applications of CBD. It is important to note that smoked cannabis has been shown to have negative impacts on the lungs. A study published in 2014 in the Journal of Pain Symptom Management found:
'The efficacy end point of change from baseline in mean Brief Pain Inventory-Short Form scores for "pain severity" and "worst pain" domains showed a decrease (i.e., improvement) at each visit in the THC/CBD spray patients. Similarly, the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-C30 scores showed a decrease (i.e., improvement) from baseline in the domains of insomnia, pain, and fatigue. No new safety concerns associated with the extended use of THC/CBD spray arose from this study." (https://www.ncbi.nlm.nih.gov/pubmed/23141881)
I was also able to find an article that concluded cannabidiol topically applied in rats provided relief from arthritic inflammation and pain. The researchers concluded "topical CBD application has therapeutic potential for relief of arthritis pain-related behaviours and inflammation without evident side-effects" (https://www.ncbi.nlm.nih.gov/pubmed/26517407).
The only research article I could find on the topical application of CBD oil in humans found that that the oil can be used to control itching in chronic pruritus, but did not address pain applications (http://link.springer.com/article/10.1007%2Fs00105-006-1180-1). It is likely that the topical application of CBD oil works similarly within the endocannabinoid system to create pain relief.
As a person who suffers from chronic back pain (due to a disc herniation at C5/6), I would like to have more definitive answers as to if CBD oil is good for pain. From a research informed perspective, I don't have definitive answers. I have heard individual people have found relief with using the oil for knee pain and back pain. This is anecdotal evidence (personal stories) and not research proven (research involves a minimum number of participants and good research meets minimum standards of controlling for other factors that might be providing negative or positive results). So, if you decide to try CBD oil, look for good quality ingredients in the oil. Is the CBD chemically isolated in a lab with strict controls? Is the CBD actually a cannabis infusion based in a quality oil or highly processed ethanol (alcohol)? Is the base product free of harsh chemicals? Can you determine if the cannabis the CBD was derived from was grown without pesticides and tested for adulterants?
Pain relief, in chronic pain conditions, can make the difference between living an active and full life or living with pain that limits our engagement with even our favorite activities and people. As a chronic pain patient and as a practitioner, I'm always looking for tools to add to the big bag of options in treating pain conditions. Topical CBD oil, anecdotally and in rat studies is promising. The studies on humans and for chronic pain are eagerly awaited. If CBD oil is shown to provide side-effect free pain relief, it will still need to be accompanied by the care of a provider. Its effects are most likely analgesic and not actually addressing the underlying issues which are causing the pain. It is important to identify the source of pain and address that condition. Pain is a signal from the body that something isn't right and needs to be addressed. As a practitioner of Chinese medicine, I want to look at all the contributing factors in your pain condition and assist the body in healing rather than just masking pain. So, if you choose to use CBD oil, continue to see your physical therapist, chiropractor, massage therapist and/or acupuncturist so that your body continues to heal even without the strong signal of pain to motivate you.