Cannabis for Insomnia: What the Research Actually Shows
What Researchers Found About Insomnia and Cannabis
The Study at a Glance
Published
CNS Drugs, 2020
Researchers
Multiple institutions (International)
Study Type
Systematic ReviewParticipants
219 patients · 2-8 weeks
Key Finding
Despite some possible signals for efficacy, the heterogeneity and high risk of bias across included trials do not reliably inform evidence-based practice. High-quality RCTs are required before drawing conclusions about cannabinoid efficacy for insomnia.
Key Finding: Despite some possible signals for efficacy, the heterogeneity and high risk of bias across included trials do not reliably inform evidence-based practice. High-quality RCTs are required before drawing conclusions about cannabinoid efficacy for insomnia.
What Researchers Studied About Insomnia and Cannabis
Insomnia is associated with significant disability and impact on quality of life. Despite advances in treatment, it remains a significant burden. Cannabinoids are gaining acceptance for use as sleep aids.
This systematic review and meta-analysis evaluated the efficacy of cannabinoids specifically for insomnia disorder.
The researchers searched for randomized and non-randomized studies examining cannabinoids for insomnia treatment.
How This Systematic Review Was Conducted
Only 5 studies with 219 participants met inclusion criteria: 2 RCTs and 3 non-randomized studies.
Three non-randomized studies could be combined for meta-analysis on the Pittsburgh Sleep Quality Index (PSQI).
One RCT (n=32) compared nabilone to amitriptyline. Another single ascending-dose RCT (n=9) tested THC at different doses vs placebo for sleep-onset latency.
Insomnia Treatment Results
The Main Results:
- 1PSQI scores improved with cannabinoids at 4+ weeks (MD -1.89, 95% CI -2.68 to -1.10, n=176)
- 2PSQI scores improved at 8 weeks (MD -2.41, 95% CI -3.36 to -1.46, n=166)
- 3Nabilone vs amitriptyline: improved Insomnia Severity Index after 2 weeks (difference -3.25, 95% CI -5.26 to -1.24)
- 4Nabilone produced more restful sleep on Leeds Sleep Evaluation Questionnaire
- 5THC reduced sleep-onset latency at 10mg, 20mg, and 30mg doses (43-62 minutes faster than placebo)
- 6ALL included studies rated as "poor quality" with high risk of bias
By the Numbers
| Statistic | What It Means |
|---|---|
| 5 studies | Total studies found (219 participants), far fewer than needed for reliable conclusions |
| -1.89 to -2.41 | Improvement in Pittsburgh Sleep Quality Index scores with cannabinoids (from non-randomized studies) |
| 43-62 min | THC reduced time to fall asleep by this amount vs placebo in one small study (n=9) |
| Poor quality | Rating given to ALL included studies due to small sizes, short duration, and high bias risk |
Total studies found (219 participants), far fewer than needed for reliable conclusions
Improvement in Pittsburgh Sleep Quality Index scores with cannabinoids (from non-randomized studies)
THC reduced time to fall asleep by this amount vs placebo in one small study (n=9)
Rating given to ALL included studies due to small sizes, short duration, and high bias risk
What This Means for Insomnia Patients
If you are considering cannabis for sleep problems, this review shows the evidence is currently too weak to recommend it.
While some studies showed "possible signals" of benefit, including faster sleep onset and improved sleep quality, ALL the studies were rated as poor quality. Sample sizes were small (the largest combined only 176 participants), treatment periods were short, and there was high risk of bias.
The researchers explicitly state that these results "do not reliably inform evidence-based practice." High-quality randomized trials are needed before conclusions can be drawn.
If you have insomnia, evidence-based treatments like cognitive behavioral therapy for insomnia (CBT-I) have much stronger research support.
Quick Answers: Insomnia 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.
Does marijuana help with sleep?
Evidence is insufficient. A 2020 systematic review found only 5 poor-quality studies (219 participants). Despite some "possible signals for efficacy," the high risk of bias means results "do not reliably inform evidence-based practice."
Source: Bhagavan et al., CNS Drugs, 2020 (PMID: 33244728)
Is there scientific evidence for cannabis as a sleep aid?
Very limited. Only 5 small studies exist for insomnia specifically, ALL rated as poor quality. The systematic review concluded that "high-quality RCTs are required before drawing any conclusions about the efficacy of cannabinoids" for insomnia.
Source: Bhagavan et al., CNS Drugs, 2020 (PMID: 33244728)
What works better than cannabis for insomnia?
No, evidence is too weak. Evidence-based treatments like cognitive behavioral therapy for insomnia (CBT-I) have much stronger scientific support and should be considered first before cannabis.
Source: Bhagavan et al., CNS Drugs, 2020 (PMID: 33244728)
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:
- Only 5 studies (219 participants) found worldwide
- ALL studies rated as "poor quality"
- Small sample sizes in all studies
- Short treatment periods
- Uncertain clinical significance of findings
- High risk of bias in all included trials
- Heterogeneous interventions and outcomes
The Bottom Line on Cannabis for Insomnia
This systematic review found only 5 small, poor-quality studies of cannabinoids for insomnia. While there were some signals of possible benefit (faster sleep onset, improved sleep scores), ALL studies had serious methodological problems. The authors conclude that high-quality trials are needed before any conclusions can be drawn. Patients seeking help for insomnia should consider evidence-based options like CBT-I rather than relying on cannabis at this time.
Do You Qualify for Medical Marijuana?
If you're living with Insomnia, you may qualify for a medical marijuana card. Our licensed physicians can evaluate you from home via telehealth.
Related Research & Resources
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- Clinical Practice Guidelines: Cannabis for Chronic Pain & Co-Occurring Conditions (2024)
- Medical Cannabis for Cancer Patients: Real-World Results
- Can CBD Help With Anxiety? What 72 Patients Experienced
Condition Research
Get Your Card
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Source
Bhagavan C, Kung S, Doppen M, et al. "Cannabinoids in the Treatment of Insomnia Disorder: A Systematic Review and Meta-Analysis" CNS Drugs. 2020. DOI: 10.1007/s40263-020-00773-x
Important Information
Study Age: This study was published 6 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 25, 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 Insomnia
Does cannabis help you sleep?
Evidence is insufficient to say. A 2020 systematic review found only 5 small, poor-quality studies. While there were some signals of possible benefit, ALL studies had high risk of bias. Results "do not reliably inform evidence-based practice."
Can THC help with insomnia?
One very small study (9 participants) found THC reduced time to fall asleep by 43-62 minutes. However, this study was rated as poor quality and is far too small to draw reliable conclusions.
Is there research on cannabis for sleep?
Very little. Only 5 studies (219 total participants) have examined cannabinoids specifically for insomnia disorder. All were rated as poor quality. High-quality randomized trials are needed before recommendations can be made.