The Impact of Cannabidiol (CBD) on Sleep Quality: A Review of Mechanisms and Clinical Evidence

Cannabidiol (CBD), a non-psychoactive component of Cannabis sativa, has garnered significant interest as a potential therapeutic agent for sleep disturbances. This review synthesizes preclinical and clinical evidence on the effects of CBD on sleep parameters, including sleep architecture, quality, and disorders such as insomnia and REM sleep behavior disorder (RBD). Preclinical studies reveal that CBD modulates sleep architecture in a dose- and region-dependent manner, influencing both slow-wave and REM sleep. These effects are mediated through complex interactions with the endocannabinoid, adenosinergic, serotonergic, dopaminergic, and GABAergic systems. Clinical trials suggest that low to moderate doses of CBD may modestly improve subjective sleep quality, particularly in individuals with co-occurring anxiety or chronic pain, although its efficacy is generally comparable to melatonin. High-dose CBD may enhance restorative sleep stages, yet the benefits are limited and inconsistently sustained. CBD demonstrates a favorable safety profile, though methodological limitations—such as small sample sizes, short follow-up durations, and product variability—impede definitive conclusions. Further research with standardized formulations, objective sleep measurements, and larger populations with diagnosed sleep disorders is needed to fully assess the therapeutic potential and clinical application of CBD for sleep-related conditions.