Efficacy of cannabinoids for insomnia and sleep disturbance: A systematic review and meta-analysis of randomized...

Insomnia is a common sleep disorder that presents with difficulty falling asleep or staying asleep. Standard hypnotics often lead to tolerance and dependency, prompting interest in cannabinoids as alternative sleep aids. This study evaluated the efficacy and safety of cannabinoids in improving sleep among adults with insomnia or poor sleep quality.

PubMed, EMBASE, Cochrane Library, Scopus, and Web of Science were searched from inception to January 2025 for randomized controlled trials (RCTs) comparing cannabinoids with placebo or melatonin. Primary outcomes were changes in Insomnia Severity Index (ISI) and Pittsburgh Sleep Quality Index (PSQI). Pooled mean differences (MD) or risk ratios (RR) with 95% confidence intervals (CI) were calculated using random-effects models.

Ten RCTs involving 2134 participants were included. Cannabinoids significantly reduced insomnia severity (MD -3.73; 95% CI -5.04 to -2.42; p < 0.001) and improved sleep quality (MD -3.94; 95% CI -5.47 to -2.40; p < 0.001). Total sleep time increased by 33.99 min (95% CI 20.39 to 47.60), and sleep efficiency improved by 4.31% (95% CI 3.00 to 5.62). Sleep onset latency was modestly reduced (MD -12.0 min; 95% CI -22.6 to -1.4; p = 0.03). Adverse events, mostly mild dizziness and dry mouth, were more frequent with cannabinoids (RR 3.96; 95% CI 1.75 to 9.00), but no serious harms were observed.

Cannabinoids improve sleep quality and duration with acceptable safety, offering a potential alternative for managing insomnia. Larger, long-term trials are warranted to define optimal dosing and sustained efficacy.