Cannabis for Chronic Pain: A Critical Look at 104 Studies
What Researchers Found About Chronic Pain and Cannabis
The Study at a Glance
Published
Pain, 2018
Researchers
University of New South Wales (Australia)
Study Type
Meta-AnalysisParticipants
9,958 patients · Various
Key Finding
This rigorous meta-analysis of 104 studies found cannabis provides modest pain relief—about 1 in 24 patients benefit—but with a high side effect burden: 1 in 6 experience harm. The authors concluded it "seems unlikely that cannabinoids are highly effective medicines" for chronic pain.
Key Finding: This rigorous meta-analysis of 104 studies found cannabis provides modest pain relief—about 1 in 24 patients benefit—but with a high side effect burden: 1 in 6 experience harm. The authors concluded it "seems unlikely that cannabinoids are highly effective medicines" for chronic pain.
What Researchers Studied About Chronic Pain and Cannabis
With cannabis widely promoted for chronic pain, researchers needed to answer the tough question: Just how effective is it really, and at what cost?
This 2018 analysis in the prestigious journal Pain examined ALL available evidence—104 studies with nearly 10,000 participants—to provide a comprehensive and honest assessment.
Unlike some reviews that only look at positive outcomes, this study used IMMPACT guidelines (the gold standard for pain research) to evaluate real-world effectiveness.
How This Meta-Analysis Was Conducted
Researchers conducted an exceptionally thorough systematic review:
• Analyzed 104 studies from 91 publications • Included 9,958 total participants • 47 randomized controlled trials + 57 observational studies • Examined neuropathic pain (48 studies), fibromyalgia (7), MS-related pain (13), and other chronic pain • Followed IMMPACT guidelines for pain outcome assessment • Calculated both Number Needed to Treat (benefit) and Harm
Chronic Pain Treatment Results
The Main Results:
- 129% achieved 30% pain relief with cannabis vs 26% with placebo
- 2Number Needed to Treat for benefit: 24 (meaning 24 patients must be treated for 1 to benefit)
- 3No significant difference for 50% pain relief
- 4Only 3mm improvement on 100mm pain scale
- 5Adverse events in 81% with cannabis vs 66% with placebo
- 6Number Needed to Harm: 6 (meaning 1 in 6 patients experience harm)
- 7No significant improvement in physical or emotional functioning
By the Numbers
| Statistic | What It Means |
|---|---|
| 104 | studies analyzed in this comprehensive review |
| 9,958 | total participants |
| 24 | patients must be treated for 1 to achieve meaningful relief |
| 6 | patients treated for 1 to experience harm (side effects) |
studies analyzed in this comprehensive review
total participants
patients must be treated for 1 to achieve meaningful relief
patients treated for 1 to experience harm (side effects)
What This Means for Chronic Pain Patients
This analysis delivers a sobering reality check for chronic pain patients considering cannabis:
The honest numbers: • About 3% more patients get meaningful relief vs placebo • You need to treat 24 people for 1 to benefit • But treat just 6 people for 1 to experience harm • The actual pain reduction is about 3mm on a 100mm scale—barely noticeable
What this means: Cannabis is not a highly effective pain medicine for most people. The number needed to treat (24) is high, and the number needed to harm (6) is low—meaning more people experience side effects than benefits.
Important context: This doesn't mean cannabis never helps anyone with pain. Some individuals do respond well. But as a population-level treatment, the evidence doesn't support cannabis as a first-line or highly effective option.
What to discuss with your doctor: • Have you tried other evidence-based treatments first? • Are you prepared for a high likelihood of side effects? • Do the potential modest benefits outweigh the risks for your specific situation?
Quick Answers: Chronic Pain and Cannabis
Direct answers based on the findings of this study:
Research Summary: Answers are based on published peer-reviewed studies and represent research findings, not medical recommendations. Individual results may vary. Always consult a healthcare provider before making treatment decisions.
How well does weed work for chronic pain?
Only modestly—about 1 in 24 patients get meaningful relief. A 2018 meta-analysis of 104 studies found marijuana provides just 3% more patients meaningful relief vs placebo, with actual pain reduction averaging only 3mm on a 100mm scale (Stockings et al., Pain).
Source: Stockings et al., Pain, 2018 (PMID: 29847469)
Is marijuana safe for chronic pain?
Side effects are common—more patients experience harm than benefit. Research shows 81% had adverse events with cannabis vs 66% with placebo. 1 in 6 patients experience harm, while only 1 in 24 benefit (2018 Pain meta-analysis).
Source: Stockings et al., Pain, 2018 (PMID: 29847469)
Should I try weed for my chronic pain?
Try other options first. A comprehensive 2018 analysis concluded cannabis is "unlikely to be highly effective" for chronic pain—benefits are modest (1 in 24 benefit) while side effects are common (1 in 6 experience harm).
Source: Stockings et al., Pain, 2018 (PMID: 29847469)
This is educational content, not medical advice
The research summarized here is for informational purposes only. Individual results may vary, and what works in studies may not work the same way for everyone. Always consult with a qualified healthcare provider before making changes to your treatment plan or starting medical cannabis therapy.
Important Limitations
This study has some caveats to keep in mind when interpreting the results:
- Included both RCTs and observational studies (different quality levels)
- Different cannabis preparations across studies
- Various pain conditions combined in analysis
- Short study durations in many trials
- Publication bias may affect results
The Bottom Line on Cannabis for Chronic Pain
This comprehensive meta-analysis of 104 studies with nearly 10,000 patients delivers an honest assessment: cannabis provides only modest pain relief, and side effects are common. With a Number Needed to Treat of 24 and Number Needed to Harm of just 6, more people experience problems than benefits. The authors concluded that "it seems unlikely that cannabinoids are highly effective medicines" for chronic pain. This doesn't mean cannabis never helps, but expectations should be realistic.
Do You Qualify for Medical Marijuana?
If you're living with Chronic Pain, you may qualify for a medical marijuana card. Our licensed physicians can evaluate you from home via telehealth.
Related Research & Resources
Related Research
- Clinical Practice Guidelines: Cannabis for Chronic Pain & Co-Occurring Conditions (2024)
- Cannabis for Pain: A Complete Overview of the Evidence
- What Does Science Actually Know About Medical Cannabis?
- Cannabis for Neuropathic Pain: Meta-Analysis of Clinical Trials
- Medical Cannabis for Fibromyalgia: What 367 Patients Experienced
Condition Research
Get Your Card
This condition qualifies for medical marijuana in:
Source
Stockings E, Campbell G, Hall WD, 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. DOI: 10.1097/j.pain.0000000000001293
Important Information
Study Age: This study was published 8 years ago. Newer research may have updated or refined these findings.
Not Medical Advice: This research summary is for educational purposes only. It should not be used to diagnose, treat, cure, or prevent any disease or medical condition. Always consult a qualified healthcare provider before starting or changing any treatment.
Individual Variation: Research findings represent group averages. Your individual response to cannabis may differ based on genetics, other medications, underlying conditions, and many other factors.
Last reviewed: January 24, 2026
Important Notices
Research Summary Disclaimer
This content represents our interpretation of published scientific research for educational purposes. It should not be used to make treatment decisions without consulting a qualified healthcare provider. Individual results may vary from study findings.
FDA Notice
These statements have not been evaluated by the FDA. Cannabis is not intended to diagnose, treat, cure, or prevent any disease. The FDA has not approved cannabis for any medical condition except specific prescription medications.
Copyright & Fair Use
Research summaries are provided under fair use (17 U.S.C. § 107) for educational purposes. We provide brief summaries with attribution, not full reproductions. All studies remain the intellectual property of their respective authors and publishers.
Data Sources
Study information sourced from PubMed®, U.S. National Library of Medicine. Inclusion does not imply endorsement by NLM, NIH, or the federal government.
For complete information, see our Terms of Use and Research Content Policy.
FAQs: Cannabis for Chronic Pain
How effective is cannabis for chronic pain?
Modestly effective at best. A meta-analysis of 104 studies found only 3% more patients get meaningful relief with cannabis vs placebo. You need to treat 24 people for 1 to benefit—a high number that suggests limited effectiveness.
What are the chances cannabis will help my chronic pain?
Statistically, about 1 in 24 patients (4%) will achieve meaningful relief that they wouldn't get from placebo. However, about 1 in 6 (17%) will experience adverse events. Individual responses vary significantly.
Is cannabis a good first treatment for chronic pain?
Modestly effective, with caveats. This meta-analysis found cannabis is unlikely to be "highly effective" for chronic pain, with a high NNT (24) and low NNH (6). Other treatments should typically be tried first.