Medical cannabis and insomnia: a Cochrane review does not confirm a clear net benefit

Nine trials, different preparations

The researchers searched for randomized trials up to April 5, 2025. Participants were aged 18 to 76 and were predominantly women. The studies focused mainly on primary insomnia, with three trials examining acute insomnia and six examining chronic insomnia.

Eight trials compared medical cannabis with placebo. Only one used an active comparator, amitriptyline, an antidepressant. Two trials assessed authorized medicines and seven assessed compounded preparations. These differences mean medical cannabis cannot be treated as a uniform intervention.

Sleep gains remain uncertain

For total sleep duration, the analysis of six studies involving 194 participants estimates a mean difference of 7.68 minutes in favor of medical cannabis compared with placebo. But the confidence interval ranges from 23.04 minutes less sleep to 38.39 minutes more. The result therefore remains compatible with a decrease, no difference or an increase in sleep time.

Neither sleep quality nor daytime functioning shows a clearly established benefit. Results vary considerably across trials, and the certainty of the evidence is very low. There is also a favorable signal for quality of life, but the uncertainty means it cannot be considered an established benefit.

Safety is no better established

Three studies involving 98 participants suggest more adverse effects with medical cannabis than with placebo. The certainty of this estimate is low. The available abstract does not detail the nature or severity of these events, limiting the practical interpretation of the risk.

The authors call for better-designed trials with more participants, longer follow-up and detailed reporting of both benefits and risks. In particular, the available data do not allow conclusions about long-term adverse effects.

What this review changes

This review does not justify presenting medical cannabis as a treatment with proven effectiveness for insomnia. Nor does it prove that no preparation could help some patients. Above all, it shows that current trials do not allow the balance between benefits and risks to be determined with sufficient confidence.

What we can take away

The benefit of medical cannabis for insomnia remains uncertain, while an increase in adverse effects is possible. This review provides no solid basis for promising better sleep.