One of the most talked about "new" treatments for chronic pain is actually centuries old: cannabidiol (CBD oil). Having been used as a medicinal treatment for more than 2,500 years, CBD oil is derived from the marijuana plant, but does not contain the THC responsible for marijuana's famous 'high.'
Early studies have shown significant promise for the use of CBD. CBD has been FDA-approved to treat two rare forms of childhood epilepsy, and more than 150 clinical trials with the chemical are ongoing. Drug products containing a combination of THC and CBD are available in many countries, including the UK, Czech Republic, Spain, Germany, Denmark, and Sweden.
Some of the most important proposed uses include reducing pain, anxiety, and inflammation.
However, research is still limited and results from human trials are still several years away. Much of what we know comes from animal models, which may not directly translate to benefits in humans. Some testing has combined CBD and THC, making it difficult to determine which is responsible for the benefits seen.
What is CBD Oil?
Cannabidiol (CBD) is one of more than 40 cannibidoids found in the marijuana plant. The two most famous are THC, which is responsible for marijuana's high, and CBD, which is not considered a psychoactive substance.
Derivatives of the marijuana plant have been used medicinally for centuries. There is evidence that that Chinese were using marijuana for medicinal purposes almost 5,000 years ago. Europeans began using it in the 1800s for analgesic properties, and it was available over-the-counter in the United States until the 1930s.
However, it was only in the last half-century we gained the ability to separate out the different cannabinoids within marijuana, isolating CBD and removing the THC. Most of the attention has been given to THC, and it's only in the last few decades that significant research on CBD has been started.
This history creates a challenge in researching the effects of CBD, because so much of both the research and anecdotal evidence comes from use of marijuana as a whole. It's hard to determine what is causing any beneficial effects - is it THC, CBD, all of the other components of marijuana, or the combination of them all?
New testing is seeking to answer these questions. While current research is relatively limited, more than 150 clinical trials are ongoing with CBD as we speak, seeking to determine the safety and efficacy of the isolate by itself.
The first FDA-approved indication for CBD oil has been for two rare forms of childhood epilepsy. After clinical testing, the FDA concluded that CBD was safe and effective for the treatment of certain forms of epilepsy in children. This approval has paved the way for additional research into other indications and uses for CBD. CBD has also been approved for several uses in European countries when combined with THC.
CBD and Anxiety
One of the most promising areas of research is in the ability of CBD to reduce anxiety. In one study of individuals diagnosed with social anxiety disorder, either 600 mg of CBD oil or a placebo was given to them prior to a public speaking test. They received the dose about 1.5 hours before they were due to speak.
Those who took CBD rather than the placebo noted reduced anxiety, discomfort, and cognitive impairment.
CBD and Pain Reduction
Another promising avenue of research is into the ability of CBD to reduce pain. Many researchers are excited about the possibility of cannabinoids and CBD to potentially reduce our reliance on opioids for pain management. Most of the testing on the analgesic properties of these compounds have been with cannabis itself, containing both THC and CBD, there is anecdotal evidence in humans for some benefit to CBD alone and there have been several intriguing studies in animal models.
In a study of rats with arthritis, researchers found that topical CBD oil penetrated the skin to reduce both swelling and pain. Inflammation markers were also reduced in the animals that were given CBD.
When patients with the inflammatory condition of rheumatoid arthritis were given a combination of THC and CBD (approximately 13.5 mg CBD and 15 mg THC) daily in an oral spray, they saw a significant reduction in several pain scales as well as improvements in sleep quality.
Cannabis (containing both CBD and THC) has been shown to be effective in relieving pain in cancer patients, though it isn't clear how much of the benefit is due to the THC or CBD (or if the combination is more effective than either alone).
CBD and Sleep
Another effect of CBD that has been reported anecdotally is the ability to help with sleep. Many who use CBD prefer to take it before bed, and report that it helps fall and stay asleep. Whether this is due to potential anti-anxiety effects or it actually causes drowsiness, it can be a beneficial side effect for many patients.
In patients with multiple sclerosis (MS), use of a product with both THC and CBD was proven to improve sleep quality; again, it is hard to determine whether that result was from the CBD, THC, or the combination.
Other Potential Benefits
CBD has also shown some intriguing benefits in animal and human trials. In patients with MS (in combination with THC), it reduce bladder spasticity and calmed an overactive bladder. Several studies have looked at the benefits of cannabis for gut health and treating colitis and inflammatory bowel disease. There is some evidence of a neuroprotective effect with cannabis, and researchers are exploring other possible applications for CBD.
There are three primary routes of administration for CBD: oral, sublingual (under the tongue), and topical. Taking any medication orally sends it through the stomach and the digestive system, where it is absorbed through the small intestines. Using the oil topically or taking it sublingually allows the CBD to penetrate directly into the bloodstream, without being processed by the digestive system first. For sublingual use, most manufacturers recommend holding the oil under your tongue for about one minute to allow it to absorb. This may increase the overall bioavailability of the CBD.
Topical use can can also allow the CBD to enter the bloodstream. As far as we know, the effects of CBD are systemic, meaning that it works throughout the body and doesn't stay confined to the place it was applied. So topical use of CBD allows it to penetrate the skin and reach the bloodstream, where it has an effect on the whole body. Putting CBD directly on a painful area will not (at least as our current understanding goes) have a direct effect on that specific area.
In measuring how long it takes for CBD to reach the bloodstream, researchers found that peak blood levels were found 1.3 hours after administration. The amount in the body begins to reduce rapidly, with half of all blood levels gone within the first two days. After a week, CBD levels were not detected in the blood.
There also isn't much information on dosage. Some studies have used up to 1,000 mg daily, others used 600 mg. Both of these are significantly higher than most users take. In an approved European formulation, a spray that delivers 2.5 mg of CBD (along with THC) is used, and can be sprayed multiple times per day, but shows efficacy at a lower dosage than other studies. In a study of rheumatoid arthritis, patients found pain relief and improved sleep with approximately 15 mg of CBD and THC daily. For oral and sublingual products, many manufacturers recommend a dosage of approximately 25 mg before bed.
When purchasing CBD, it's important to make sure the product comes from a reputable company and testing has been conducted to ensure the purity and composition of the product. In one study that looked at more than 75 products, the authors found that only 17% of the products were accurately labelled. A good manufacturer should be able to show you testing results demonstrating the purity of the product.
You'll also want to check the amount of THC (if any) in the product. Many products contain no THC at all. Others advertise they are less than 0.3% THC, which qualifies them as hemp-based products. In some states you may find blends with both CBD and THC. Don't be afraid to ask questions and review the test results of the company prior to making a purchasing decision.
CBD is full of promise, and we're starting to see the science catch up to the hype. We'll continue learning a lot more about how effective it is and what the right dosage is over the next several years as more trials are done. Many patients do have anecdotal reports of CBD helping with pain, inflammation, or sleep quality, and so far trials have not identified major adverse events or health risks to CBD. If you are thinking of trying CBD, consider a symptom log to track your symptoms and see how it affects your body. Always make sure to purchase from a reputable source. It's always best to consult with your doctor prior to beginning any new supplement, and CBD is no exception. Hopefully we will see positive results coming from trials and a new treatment option become available for those dealing with pain, anxiety, or inflammation.
Dr. Nicole Cozean is the founder of PelvicSanity physical therapy, Orange County's premier pelvic floor physical therapy clinic. Nicole was named the 2017 IC Physical Therapist of the Year, was the first PT to serve on the ICA Board of Directors, and is the author of the award-winning book The Interstitial Cystitis Solution (2016). She is an adjunct professor at her alma mater, Chapman University.