A Double-Blind, Randomized, Placebo-Controlled Study of the Safety and Effects of CBN With and Without CBD on Sleep Quality

The present study sought to determine the effects of cannabinol (CBN) alone and in combination with cannabidiol (CBD) on sleep quality. This was a double-blind, randomized, placebo-controlled study conducted between May and November 2022. Participants were randomized to receive either (a) placebo, (b) 20 mg CBN, (c) 20 mg CBN + 10 mg CBD, (d) 20 mg CBN + 20 mg CBD, or (e) 20 mg CBN + 100 mg CBD for seven consecutive nights. Participants were 18-55 years of age who self-rated sleep quality as "very poor" or "poor." The primary endpoint was sleep quality, while secondary endpoints included sleep onset latency, number of awakenings, wake after sleep onset (WASO), overall sleep disturbance, and daytime fatigue. In a modified intent-to-treat analyses (N = 293), compared to placebo, 20 mg CBN demonstrated a nonsignificant but potentially meaningful effect on sleep quality (OR [95% CI] = 2.26 [0.93, 5.52], p = .082) and significantly reduced number of awakenings (95% CI [−0.96, −0.05], p = .025) and overall sleep disturbance (95% CI [−2.59, −0.14], p = .023). There was no difference from placebo among any group for sleep onset latency, WASO, or daytime fatigue (all p > .05). Individuals receiving 20 mg CBN demonstrated reduced nighttime awakenings and overall sleep disturbance relative to placebo, with no impact on daytime fatigue. The addition of CBD did not positively augment CBN treatment effects. No differences were observed for latency to sleep onset or WASO. Findings suggest 20 mg of CBN taken nightly may be helpful for improving overall sleep disturbance, including the number of times one wakes up throughout the night, without impacting daytime fatigue. Public Health Significance The present study serves as the first placebo-controlled study of CBN for sleep. This study demonstrated that 20 mg CBN was effective in improving several aspects of sleep, including nighttime awakenings and overall sleep disturbance, without impacting daytime fatigue. Adding CBD to CBN did not appear to positively augment the effects of CBN alone.