Meta-Analysis: Cannabinoids Improve Sleep Quality, But CBD Alone Does Not

Across six randomized trials with 1,077 patients, cannabinoids improved self-reported sleep quality compared to placebo, but the effect was driven by non-CBD cannabinoids; CBD-only therapies showed no significant benefit.

da Silva, Giovanna Hanike Santos et al.·Sleep medicine reviews·2025·Moderate EvidenceMeta-Analysis
RTHC-06285Meta AnalysisModerate Evidence2025RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Meta-Analysis
Evidence
Moderate Evidence
Sample
Not reported

What This Study Found

Cannabinoids significantly improved sleep quality compared to placebo (SMD 0.53, P = 0.04), with stronger effects in people with insomnia or poor sleep (SMD 0.60, P = 0.02). Non-CBD cannabinoids showed greater efficacy (SMD 0.82, P = 0.005), while CBD-only therapies showed no significant effect (SMD 0.13, P = 0.61).

Key Numbers

Overall cannabinoids vs placebo: SMD 0.53 (95% CI 0.03-1.02, P = 0.04, I2 = 88%). Non-CBD: SMD 0.82 (P = 0.005). CBD-only: SMD 0.13 (P = 0.61). Insomnia subgroup: SMD 0.60 (P = 0.02).

How They Did This

Systematic review and meta-analysis of randomized controlled trials from MEDLINE, Embase, and Cochrane databases comparing cannabinoids vs placebo for sleep quality in adults.

Why This Research Matters

Many people use cannabis products, especially CBD, for sleep. This meta-analysis suggests CBD alone may not help, while THC-containing cannabinoids show meaningful benefit.

The Bigger Picture

The sleep supplement market is flooded with CBD products, but this evidence suggests CBD alone does not improve sleep in controlled trials. THC or mixed cannabinoid formulations appear to be the active ingredients for sleep.

What This Study Doesn't Tell Us

Only six trials included. High heterogeneity (I2 = 88%). Different cannabinoid formulations, doses, and populations across studies. Subjective sleep measures only.

Questions This Raises

  • ?Why does CBD alone not improve sleep despite widespread consumer reports?
  • ?What specific non-CBD cannabinoids are most effective?
  • ?Do benefits persist long-term?

Trust & Context

Key Stat:
Non-CBD cannabinoids: SMD 0.82 (P = 0.005); CBD alone: SMD 0.13 (P = 0.61)
Evidence Grade:
Meta-analysis of RCTs, the gold standard design, but limited by only six trials and high heterogeneity.
Study Age:
2025 meta-analysis of recent randomized trials
Original Title:
Effectiveness of cannabinoids on subjective sleep quality in people with and without insomnia or poor sleep: A systematic review and meta-analysis of randomised studies.
Published In:
Sleep medicine reviews, 84, 102156 (2025)
Database ID:
RTHC-06285

Evidence Hierarchy

Meta-Analysis / Systematic ReviewCombines many studies into one answer
This study
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / Observational
Case Report / Animal Study

Combines results from multiple studies to find an overall pattern.

What do these levels mean? →

Frequently Asked Questions

Does CBD help with sleep?

According to this meta-analysis, CBD-only therapies did not significantly improve sleep quality compared to placebo across randomized trials. Non-CBD cannabinoids (likely THC-containing) showed significant benefit.

What does SMD 0.53 mean?

Standardized mean difference of 0.53 represents a medium effect size, meaning cannabinoids produced a meaningful but not dramatic improvement in sleep quality compared to placebo.

Read More on RethinkTHC

Cite This Study

RTHC-06285·https://rethinkthc.com/research/RTHC-06285

APA

da Silva, Giovanna Hanike Santos; Barbosa, Eduardo Cerchi; de Lima, Fernanda Ribeiro; Barroso, Douglas Carneiro; Paez, Loyná Euá Flores E; Guimarães, Felipe Bandeira de Melo; Lança, Saulo Bernardo; de Faria, Stephanie Brito Ceolin; Petrucci, Arthur Bezerra Cavalcanti; Garbacka, Alicja; Walsh, Jennifer H. (2025). Effectiveness of cannabinoids on subjective sleep quality in people with and without insomnia or poor sleep: A systematic review and meta-analysis of randomised studies.. Sleep medicine reviews, 84, 102156. https://doi.org/10.1016/j.smrv.2025.102156

MLA

da Silva, Giovanna Hanike Santos, et al. "Effectiveness of cannabinoids on subjective sleep quality in people with and without insomnia or poor sleep: A systematic review and meta-analysis of randomised studies.." Sleep medicine reviews, 2025. https://doi.org/10.1016/j.smrv.2025.102156

RethinkTHC

RethinkTHC Research Database. "Effectiveness of cannabinoids on subjective sleep quality in..." RTHC-06285. Retrieved from https://rethinkthc.com/research/da-2025-effectiveness-of-cannabinoids-on

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.