ABSTRACT OBJECTIVE BACKGROUND: The use of cannabis to improve sleep quality and treat sleep-related disorders has received increased attention due to the expanded legalization of cannabis for medical use in 36 states and Washington DC. Data on the effects of delta-9-tetrahydrocannabinol (THC), in combination with cannabinol (CBN), on sleep is preliminary; however, preclinical research indicates that CBN may prolong sleep and be particularly effective when combined with other cannabinoids. OBJECTIVE: The aim of this study was to evaluate the effect of a repeat-action tablet containing 10 mg THC and 5 mg CBN on sleep quality, sleep duration, and awakenings in participants (medical cannabis users)....