Clinical Research Shows Cannabis Relieves Pain… so why is access so limited?

By Jahan Marcu, Ph.D., Chief Science Officer for Americans for Safe Access

With over 100,000 active members in all 50 states, Americans for Safe Access (ASA) is the largest national member-based organization of patients, medical professionals, scientists, and concerned citizens promoting safe and legal access to cannabis for therapeutic use and research.

ASA works to overcome political and legal barriers by creating policies that improve access to medical cannabis. One method is to share the facts when it comes to research.

Clinical research analysis on cannabis and pain studies

Chronic pain conditions are the most prevalent form of disease in many countries. With few alternatives and a lack of safe and effective treatments for disabling pain, millions will continue struggling to function in their daily lives. Given the public health issues surrounding long-term use of opioid medications, researchers have been analyzing the clinical trials that have investigated the effects of cannabis across more than 15 years of study.

Since 2001, at least nine other clinical reviews have been published by various groups on randomized controlled trials (RCTs) involving cannabis and pain. In recent years, several new clinical papers have been published, which have investigated the ability of cannabis and cannabinoids to treat pain caused by a variety of conditions.

The clinical trials administered cannabis in different forms (smoked, extracts, oral THC, synthetic analogues). Three recent reviews of the clinical trials on cannabinoids and pain demonstrate that researchers agree with the published data: cannabis and its preparations are effective for treating certain types of chronic pain with acceptable side effects.

After review of 43 RCTs (a total of 2,437 patients) involving various types of cannabis-based medicines (CBMs) and various pain conditions, researchers from Israel concluded that:

“In comparison to other indications, CBMs have most extensively been investigated on NP (neuropathic pain) and evidence suggests a moderate to good treatment effect. Furthermore, NP patients should be advised that the inhalation of cannabinoids showed relatively better pain reduction effects than other routes of administration.” (Aviram & Samuelly-Leichtag, 2017)

A study published this year also examined the role of cannabis in helping to alleviate pain:

“Collectively, this research indicates that although the results of experimental studies with healthy adults are mixed, there is converging evidence to support the notion that cannabis can produce acute pain-inhibitory effects among individuals with chronic pain.” (Hill, Palastro, Johnson, & Ditre, 2017)

Another pain research group published a similar review, years earlier, that stated:

“This systematic review of 18 recent good quality randomized trials demonstrates that cannabinoids are a modestly effective and safe treatment option for chronic non-cancer (predominantly neuropathic) pain. Given the prevalence of chronic pain, its impact on function and the paucity of effective therapeutic interventions, additional treatment options are urgently needed.” (Lynch & Campbell, 2011)

These observations, from three different groups of researchers, agree with determinations made by authors of the recent National Academies report on cannabis that there is ‘‘conclusive or substantial evidence’’ of benefit from cannabis or cannabinoids for chronic pain.

An impressive body of literature supports the use of cannabis in pain conditions, and recently, this has been supplemented by an increasing number of phase I–III clinical trials. Cannabis-based medicines are currently available in various countries for pain treatment, and cannabinoids of botanical origin may be approvable by the FDA. We will continue to track this research. For more information, visit:

About Jahan Marcu, Ph.D.

Jahan Marcu, Ph.D. is the Chief Science Officer for Americans for Safe Access and Director of Patient Focused Certification. He is also a contributing author and editor of several scientific and regulatory publications, and is a court-qualified cannabis and synthetic cannabinoid expert.