Cannabis and similar substances that interact with the body’s natural cannabinoid receptors could be viable candidates for pain management and treatment, according to new research published in the journal Experimental and Clinical Psychopharmacology.

“Currently, more than 30 states have policies in place that permit medicinal cannabis use; many of these cite pain conditions as inclusionary criteria. However, despite expanding use, what we know about ‘how’ and ‘why’ cannabinoids alleviate pain remains poorly understood,” said study author Julio A. Yanes, a graduate research assistant and National Research Service Award Fellow at Auburn University.

The researchers conducted a meta-analysis of previous research that had examined cannabinoid-induced alterations in pain ratings. They identified 25 peer-reviewed studies that met their criteria, which included 2,248 participants in total.

All of the studies compared either whole-plant cannabis, cannabis extracts, or synthetic cannabinoids to a placebo.

The meta-analysis found that cannabinoid administration was associated with greater pain reduction than placebo administration.

“Although our meta-analysis results suggest that cannabinoids are efficacious pain management options, more research is needed,” Yanes told PsyPost.

“For example, our follow-up meta-regression results revealed that study sample size was associated with observed pain reduction, such that smaller samples were associated with bigger effects. Thus, large (i.e., sufficiently powered) studies are warranted.”

Scientists are learning more about how cannabis interacts with the brain and the body’s endogenous cannabinoid system. But the mechanisms behind cannabis-induced pain reduction are still unclear.

“Our meta-analysis doesn’t address ‘how’ or ‘why’ cannabinoids were more effective than placebos. One important challenge facing the field is to determine the neurobiological mechanisms that may support cannabis-related pain reduction,” Yanes said.

The study, “Effects of Cannabinoid Administration for Pain: A Meta-Analysis and Meta-Regression“, was authored by Julio A. Yanes, Zach E. McKinnell, Meredith A. Reid, Jessica N. Busler, Jesse S. Michel, Melissa M. Pangelinan, Matthew T. Sutherland, Jared W. Younger, Raul Gonzalez, and Jennifer L. Robinson.