Cochrane Review Finds Weak Evidence for Medical Cannabis in Insomnia
A Cochrane review of nine studies involving 537 adults found insufficient evidence that medical cannabis meaningfully improves sleep quality, sleep duration, or daytime functioning in people with insomnia. Compared with placebo, regulated THC/CBD products showed little to no clinically important benefit, while users were more likely to report mild side effects such as dry mouth and dizziness. The authors conclude that current evidence cannot support medical cannabis as an insomnia treatment.
The review combined nine trials involving 537 adults aged 18–76, mostly with primary insomnia. Eight compared regulated THC/CBD products with placebo; one compared them with amitriptyline. Researchers examined sleep quality, satisfaction, total sleep time, daytime functioning, and quality of life.
Evidence certainty was very low to low, limited by bias risk, inconsistent results, small samples, varied cannabis products, and follow-up of at most 12 weeks. Participants skewed younger and female (72.66%), so findings may not apply to men, older adults, or those with other conditions.
This review may temper expectations among insomnia patients considering medical cannabis and could encourage clinicians to emphasize uncertain benefits and possible dry mouth or dizziness. It may also shape future research priorities toward larger, longer, more representative trials. Because evidence is weak, access or coverage decisions could remain cautious, but the findings do not prove ineffectiveness.