If you've done an internet search for "CBD," you might think it's a miracle drug. CBD (or cannabidiol) is being sold as gummies, creams, oils, tea, drops and vapes. It's touted as a medicine, a supplement and a cosmetic, and it's even marketed for pets. Though it's the second most active substance in cannabis (also called marijuana or hemp), CBD does not make you high. And it's not addictive.
CBD is, in fact, a billion-dollar business. The problem is, there's very little valid research to support any health benefits from CBD.
Still, some people with long-term (chronic) pain are using CBD for pain relief.
What the research says
Research on cannabis for pain has focused on cannabis that includes CBD and THC (tetrahydrocannabinol), the most active substance in cannabis. Both are called cannabinoids, and THC is the one that works in your brain to make you feel high. There have been many studies, and the weight of the evidence is not especially encouraging. A review of 47 studies that included close to 5,000 people with chronic pain (not including cancer pain) found evidence of a small benefit for CBD when compared with a placebo. Side effects were common, and the review concluded that the difference between cannabis and the placebo could be too small to be meaningful.
Research on CBD alone for pain is still in the early stages. Findings from early studies, done only on animals, indicate that CBD may reduce the inflammation and pain of arthritis. It may also reduce neuropathic pain along with the anxiety caused by this type of pain, but this research has only been shown in rodents. Animal research may pave the way for futures studies in humans, but it's not sufficient on its own.
In a 2016 study from the European Journal of Pain, rats treated with CBD gel absorbed through the skin (topical CBD), had a reduction in pain and inflammation caused by arthritis. The researchers concluded that CBD has the potential to relieve arthritis pain in humans.
Using CBD for anxiety has been studied in humans, though only in a few small studies. However, they did have encouraging results — that CBD may have a calming effect on anxiety. This could help people suffering from chronic pain. According to the Institute for Chronic Pain, pain and anxiety often go hand-in-hand. Pain can trigger anxiety, and anxiety can make pain seem worse.
A 2019 study of 47 people with a primary concern of anxiety found that about 80 percent experienced reduced anxiety when CBD was added to their other treatments. However, the participants were not compared with a placebo group (people who did not use CBD), so the findings would need to be supported by a larger placebo-controlled study, according to the researchers.
If research in humans eventually does show that CBD is a safe and effective treatment for pain, it could be a real breakthrough. Neuropathic pain is chronic pain caused by nerve damage, and a common example — peripheral neuropathy — affects more than 20 million people in the United States. Up to 70 percent of diabetics have this type of pain. According to the Arthritis Foundation, more than 50 million adults in the United States suffer with arthritis.
What's legal, what's not
Cannabinoids come from the marijuana plant Cannabis sativa. Cannabis with a high THC content is considered to be marijuana, and marijuana is still considered to be illegal by the U.S. federal government, even if it is legal in some states. However, the 2018 Farm Bill removed cannabis containing less than 0.3 percent THC from the controlled substance laws, allowing it to now be legally grown as hemp. That made CBD legal, but with some restrictions. For instance, it's still illegal to sell CBD products across state lines. Use of CBD within states is now legal, but some states have restrictions so you would need to check your state laws on CBD products.
To date, the only approved use of CBD is by prescription for treating a rare type of childhood epilepsy. The U.S. Food and Drug Administration (FDA) has not approved the inclusion of CBD in food products or in diet supplements. However, the agency has recognized that many producers of CBD are claiming unproven benefits, and the U.S. Federal Trade Commission has issued warnings to CBD producers who have marketed CBD as a treatment for cancer, Alzheimer’s disease, fibromyalgia, substance abuse, psychiatric disorders and diabetes.
All about safety
When the FDA went through the approval process for the CBD epilepsy drug, it studied the safety of CBD and noted three safety issues to consider. CBD may have side effects, it may cause liver damage in high doses, and it can interfere with several medications.
According to the National Institutes of Health, CBD may be safe when taken by mouth or as an oral spray at doses of up to 300 milligrams (mg) a day for up to 6 months. The problem is that, without FDA regulation of CBD products, it's hard for a purchaser to know if you're truly getting the dose indicated by the manufacturer. A recent analysis of 84 CBD products sold online found that 43 percent contained significantly more CBD than advertised.
Reported possible side effects include:
The list of medications that can affected by CBD is quite long and includes drugs that have side effects of sleepiness, drugs that are broken down or changed (metabolized) in the liver, blood thinners, heart medications and several drugs taken for arthritis.
CBD is not considered safe for women who are pregnant or breastfeeding. It may not be safe if you have liver disease. It could be dangerous to use CBD in place of medical treatments that have been shown to be effective for treating chronic pain. Your pain or your disease could get worse.
If you decide to try CBD, you should talk to your doctor first to make sure CBD would be safe for you.
If you're taking CBD for pain …
Knowing all of this, some people still want to try CBD as a way to ease their chronic pain.
Because CBD has not been tested in humans to find the best dose for pain relief, the best advice is to start with a low dose and go slow. Keep in mind that CBD can be expensive, and the price goes up with higher doses.
Side effects may also go up with higher doses. In the recent study using oral CBD for anxiety, doses were under 200 mg, and there were very few side effects reported. Two study participants complained of fatigue and three complained of sleepiness.
CBD may also be taken as an oil or cream that you rub on your skin, called topical treatment. Topical use of CBD has not been studied enough to know the proper dose or possible side effects.
Inhaling CBD as a vapor (vaping) is another option, but it's one that health experts agree should be avoided. The FDA recently warned that vaping any oil products could cause severe lung disease.
The bottom line
Before using CBD, it's important to check with your doctor to see if CBD would be safe for you. Make sure it will not interfere with any medications you are taking. The best evidence available so far from animal studies is that CBD may help with pain due to inflammation from arthritis or pain from nerve damage. However, until more guidance becomes available from large and well-controlled studies in humans, the jury is still out on CBD for pain. Work with your doctor to weigh the risks and benefits.
- UCI Health, CBD for pain relief: Does it work? http://www.ucihealth.org/blog/2019/07/cbd-pain-relief
- CDC, What You Need to Know (And What We’re Working to Find Out) About Products Containing Cannabis or Cannabis-derived Compounds, Including CBD, https://www.fda.gov/consumers/consumer-updates/what-you-need-know-and-what-were-working-find-out-about-products-containing-cannabis-or-cannabis
- NIH, NCCIH, Cannabis (Marijuana) and Cannabinoids: What You Need To Know, https://nccih.nih.gov/health/marijuana-cannabinoids
- Harvard Medical School, Cannabidiol (CBD) — what we know and what we don’t, https://www.health.harvard.edu/blog/cannabidiol-cbd-what-we-know-and-what-we-dont-2018082414476
- NIH, Cannabidiol, https://medlineplus.gov/druginfo/natural/1439.html
- Arthritis foundation, CBD for Arthritis Pain: What You Should Know, https://www.arthritis.org/health-wellness/healthy-living/managing-pain/pain-relief-solutions/cbd-for-arthritis-pain
- European journal of pain, Transdermal cannabidiol reduces inflammation and pain-related behaviors in a rat model of arthritis, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4851925/
- Medscape, Repeated CBD Doses Required for Effective Pain Relief, https://www.medscape.com/viewarticle/904290
- NIH, Peripheral Neuropathy Fact Sheet, https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Fact-Sheets/Peripheral-Neuropathy-Fact-Sheet
- Rheumatoid Arthritis Support Network, Does CBD Oil Really Help Treat Arthritis pain? https://www.rheumatoidarthritis.org/cbd-oil/
- ICP, Anxiety, http://www.instituteforchronicpain.org/understanding-chronic-pain/complications/anxiety
- The Permanente Journal, Cannabidiol in Anxiety and Sleep: A Large Case Series, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6326553/
- Serious Health Claims for CBD Products Need Proof, FTC, 2019. https://www.consumer.ftc.gov/blog/2019/09/serious-health-claims-cbd-products-need-proof