Medical Marijuana Eases Chronic Pain But Only With High Levels Of THC, Not CBD, Researchers Conclude

Some orally ingested cannabis products can provide short-term relief of chronic pain, according to one of the largest-ever reviews of studies on marijuana use for this purpose. Products with high ratios of tetrahydrocannabinol (THC) to cannabidiol (CBD) seem to offer the most significant pain reduction, reported the New Scientist.

The most commonly reported use of medical marijuana in the U.S. is to alleviate pain and it has been lauded as an effective alternative to opioids. More than 20% of adults in the U.S. live with chronic pain, according to the Centers for Disease Control and Prevention.

Yet despite the increased accessibility of cannabis, research into its medicinal benefits remains limited due mostly to its federal classification as a Schedule I substance, claiming it has no medical benefits. 

Oregon Researchers Get To The Bottom Of An Important Question

To determine whether cannabis can reduce chronic pain and how the THC to CBD ratio impacts efficacy, said Marian McDonagh, Pharm.D., emeritus professor of medical informatics and clinical epidemiology at the Oregon Health & Science University. McDonagh and her team pored over previous research and lots of it.

“We wanted to know, would cannabis for treating chronic pain have any kind of similar benefits [to opioids]? And of course, we really wanted to look deep into the adverse side effects side, particularly the more serious ones,” McDonagh said.

They proceeded to search through more than 3000 studies before identifying 25 that met their stringent criteria, which included those that had spanned at least four weeks and included people with different kinds of pain, such as back pain, chronic headaches and diabetic neuropathy. Of the 25 studies, 18 compared cannabis products to placebos. 

The analysis they chose ultimately included data for more than 14,000 participants. 

What Did The Data Reveal?

Some cannabis products provide minor to moderate pain reduction, however, those with high THC to CBD ratios were most likely to help alleviate discomfort.

Participants that used products containing at least 98% THC reported a roughly 30% reduction in pain symptoms while there was no significant improvement in those who consumed products with lower amounts of THC and higher amounts of CBD. People who experienced the greatest benefits were those with neuropathic pain. 

The effects of cannabis and related products are based on their ability to mimic the body’s own endocannabinoid system.

“There is so much noise out there about CBD really being able to treat pain,” McDonagh said. “This might help down the road to clarify whether that’s true or not. Right now, there’s just not enough evidence.”

The federally funded review, which will be updated on an ongoing basis, was published on Monday in the Annals of Internal Medicine.

Photo by Diane Serik on Unsplash