CBD For Pain: Does It Actually Work

id="article-body" class="row" section="article-body"> Most medical marijuana users take CBD for pain. But does it work?

Picture Alliance/Getty Images Cannabidiol, or CBD, one of many compounds found in the cannabis plant, appears to be the health industry's new shining star, with producers hawking it as a quick-fix for everything from anxiety to attention deficit hyperactivity disorder (ADHD), despite it only recently becoming legal in the US. But, according to recent research, out of the 62 percent of people who use CBD to treat a medical condition, most use it to manage chronic pain, arthritis and joint pain.

This story discusses substances that are legal in some places but not in others and is for informational purposes only, not for the purpose of providing legal advice. You shouldn't do things that are illegal -- this story does not endorse or encourage illegal drug use. 

"I think there's definitely a lot of excitement about [medical marijuana]," says Kevin Boehnke, Ph.D., research investigator in the department of anesthesiology and the Chronic Pain and Fatigue Research Center at the University of Michigan. "It's always nice to have an extra tool in the toolbox, especially one that has been used for thousands of years and that people know to be relatively safe." 

But safe and effective are two different things. When it comes to treating pain, does CBD actually work, and how well?

Now playing: Watch this: The future of medicinal marijuana is personalized pot 2:31 What constitutes 'pain'?
Before digging into the research, it's helpful to understand how experts classify "pain." 

"In the [research] group that I'm part of, we think of pain as coming in three different flavors," says Boehnke. "One of them is neuropathic pain, and that's caused by damage to or inflammation of the nerves." Think: carpal tunnel syndrome or sciatica. 

"Then there's acute, or nociceptive, pain," says Boehnke, acute pain typically occurs as a result of an injury or tissue damage, like a broken bone or arthritis caused by bone rubbing on bone. 

"Lastly, there is centralized pain, which has very recently been called nociplastic," says Boehnke. "And that's something more like fibromyalgia or some of the other chronic overlapping pain conditions -- migraines, tension headaches -- that have been more difficult to characterize scientifically and clinically because there's not a specific pathology that you can identify on an x-ray or fMRI." 

Because the different types of pain don't always respond to medication the same way, it can be difficult to make sweeping generalizations about the effect of CBD on pain. But, with that said, here's what researchers know so far.

Early research is... not super-helpful
Want to look at the high-quality studies that specifically test CBD's effect on pain? Well, there aren't any. Up until December of 2018, CBD was classified by the federal government as a Schedule I substance (along with marijuana), making it extremely difficult to study. Now that CBD is legal under circumstances, that might change.

CBD oil is a popular way to take medical marijuana. 

R+R Medicinals/Unsplash "There's a lot of studies that have been done in animals and those tend to show that it's anti-inflammatory and that it does have some analgesic effect," says Boehnke. "Unfortunately they haven't been well translated in humans."

But that's not to say studies focusing on medical marijuana and pain don't exist. They do. They just tend to look at the use of CBD in conjunction with THC, or delta-9-tetrahydrocannabinol, nissankediri the compound in cannabis that can make you "high." That's because researchers believe the two work better together. 

"It seems like if you take them together, you can tolerate more THC without having the same types of side effects," says Boehnke, referring to THC's penchant for causing intoxication and impairment. "Also, taking CBD and THC together, compared to a similar amount of THC alone or CBD alone, seems to have better analgesic effects."

There have actually been a number of meta-analyses published evaluating the strength of data on cannabis and pain. The problem is, they've come to somewhat conflicting conclusions. 

A 2017 review by the Department of Veterans Affairs found "low-strength evidence that cannabis preparations with precisely defined THC-cannabidiol content (most in a 1:1 to 2:1 ratio) may alleviate neuropathic pain but insufficient evidence in populations with other types of pain." 

But a report from the National Academies of Sciences, Engineering and Medicine (NASEM) published that same year concluded that there was "conclusive or substantial evidence" that cannabis is effective in treating chronic pain, as well as nausea and vomiting after chemotherapy and multiple sclerosis-related muscle spasms and stiffness. 

And yet a third review, this time from Cochrane, one of the most highly respected research organizations, found that "there is a lack of good evidence that any cannabis-derived product works for any chronic neuropathic pain." 

Why experts are still hopeful
Available research may seem like a bummer, but it comes with a lot of caveats that may actually work in favor of cannabis. 

"In all of these systematic reviews, they mention the limitations of existing studies," says Boehnke. "They are typically small studies. They don't give cannabis or cannabinoids to people for a long period of time. They don't do a good job of figuring out the exact underlying pain phenotype. And, maybe most important, they don't use cannabis products that are representative of what people are using today." 

One reason why is the US Drug Enforcement Administration's (DEA) stronghold on the legal production of marijuana for research. The University of Mississippi, which is funded by the National Institute On Drug Abuse, is currently the only DEA-authorized marijuana supplier. In 2016, the DEA said it would accept applications for additional suppliers, but those efforts appear to have stalled within the Trump administration.