Large Meta-Analysis Found Cannabis Provides Only Modest Pain Relief With Significant Side Effects
Across 104 studies with nearly 10,000 participants, cannabinoids provided a statistically significant but clinically small reduction in chronic pain (equivalent to 3 mm on a 100 mm scale), with a high rate of adverse events.
Quick Facts
What This Study Found
For 30% pain reduction: 29% on cannabinoids vs 25.9% on placebo (NNT=24). For 50% pain reduction: no significant difference. Overall pain intensity reduction was equivalent to just 3 mm on a 100 mm visual analogue scale. Adverse events were common: NNH was only 6 (81.2% vs 66.2%). No significant impacts on physical or emotional functioning.
Key Numbers
104 studies, 9,958 participants. NNT for 30% pain reduction: 24 (CI 15-61). Pain intensity reduction: 3 mm on 100 mm scale. NNH for adverse events: 6 (CI 5-8). 48 studies on neuropathic pain, 7 on fibromyalgia.
How They Did This
Systematic review and meta-analysis of 104 studies (47 RCTs, 57 observational) with 9,958 participants, searched across MEDLINE, Embase, PsycINFO, CENTRAL, and clinicaltrials.gov. IMMPACT guidelines followed.
Why This Research Matters
This is one of the largest and most rigorous meta-analyses of cannabinoids for chronic pain. Its sobering conclusion challenges the widespread belief that cannabis is highly effective for pain, while noting that some patients do benefit.
The Bigger Picture
While cannabis is widely promoted for pain, this meta-analysis suggests the average benefit is small and comes with frequent side effects. However, the NNT of 24 is not zero - some patients do experience meaningful relief, and cannabis may still be preferable to more dangerous alternatives like opioids.
What This Study Doesn't Tell Us
Heterogeneity across studies in cannabinoid type, dose, formulation, and pain condition. Most RCTs were relatively short-term. Publication bias possible. Average effects may mask meaningful responses in subgroups.
Questions This Raises
- ?Are there identifiable subgroups who respond better to cannabinoids for pain?
- ?Would different cannabinoid formulations or doses produce better results?
- ?How does cannabinoid pain relief compare to other analgesics on the same scale?
Trust & Context
- Key Stat:
- NNT of 24 for 30% pain reduction and NNH of 6 for adverse events suggest cannabinoids are unlikely to be highly effective pain medicines for most patients.
- Evidence Grade:
- Strong - large, rigorous meta-analysis following IMMPACT guidelines with nearly 10,000 participants across 104 studies.
- Study Age:
- Published in 2018. Literature searched through July 2017.
- Original Title:
- Cannabis and cannabinoids for the treatment of people with chronic noncancer pain conditions: a systematic review and meta-analysis of controlled and observational studies.
- Published In:
- Pain, 159(10), 1932-1954 (2018)
- Authors:
- Stockings, Emily(3), Campbell, Gabrielle(6), Hall, Wayne D(6), Nielsen, Suzanne, Zagic, Dino, Rahman, Rakin, Murnion, Bridin, Farrell, Michael, Weier, Megan, Degenhardt, Louisa
- Database ID:
- RTHC-01843
Evidence Hierarchy
Combines results from multiple studies to find an overall pattern.
What do these levels mean? →Frequently Asked Questions
Does cannabis actually help with chronic pain?
This meta-analysis of 104 studies found that cannabis provides a real but very small average pain reduction - equivalent to 3 mm on a 100 mm scale. About 29% of cannabis users achieved 30% pain reduction vs 26% on placebo. Side effects were common.
How effective is cannabis compared to other pain medications?
Based on this analysis, the number needed to treat for cannabis to achieve 30% pain reduction was 24, which is high compared to many conventional analgesics. However, cannabis may be considered when other options carry greater risks, such as opioids.
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Cite This Study
https://rethinkthc.com/research/RTHC-01843APA
Stockings, Emily; Campbell, Gabrielle; Hall, Wayne D; Nielsen, Suzanne; Zagic, Dino; Rahman, Rakin; Murnion, Bridin; Farrell, Michael; Weier, Megan; Degenhardt, Louisa. (2018). Cannabis and cannabinoids for the treatment of people with chronic noncancer pain conditions: a systematic review and meta-analysis of controlled and observational studies.. Pain, 159(10), 1932-1954. https://doi.org/10.1097/j.pain.0000000000001293
MLA
Stockings, Emily, et al. "Cannabis and cannabinoids for the treatment of people with chronic noncancer pain conditions: a systematic review and meta-analysis of controlled and observational studies.." Pain, 2018. https://doi.org/10.1097/j.pain.0000000000001293
RethinkTHC
RethinkTHC Research Database. "Cannabis and cannabinoids for the treatment of people with c..." RTHC-01843. Retrieved from https://rethinkthc.com/research/stockings-2018-cannabis-and-cannabinoids-for
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.