Cannabinol with or without CBD for sleep quality Original paper

The results of this randomized controlled trial suggest that supplementing with cannabinol can improve some measures of sleep quality. However, supplementing with cannabinol + cannabidiol had no effect on measures of sleep quality.

This Study Summary was published on February 2, 2024.

Quick Summary

The results of this randomized controlled trial suggest that supplementing with cannabinol can improve some measures of sleep quality. However, supplementing with cannabinol + cannabidiol had no effect on measures of sleep quality.

What was studied?

Whether supplementing with cannabinol (CBN) alone or in combination with cannabidiol (CBD) improves sleep quality.

The primary outcome was sleep quality, assessed using a sleep diary.

The secondary outcomes included sleep onset latency (the time it takes to fall asleep), the number of awakenings throughout the night, and wake after sleep onset, all measured using a sleep diary; overall sleep disturbance, measured using the PROMIS Sleep Disturbance-Short Form; and daytime fatigue, measured using a visual analog scale.

Who was studied?

293 participants (ages 18–55; 62% women, 38% men) who self-rated their sleep quality as “poor” or “very poor”.

How was it studied?

In this 7-day randomized controlled trial, the participants were assigned to take one of the following at 90 minutes before bedtime: (i) 20 mg of CBN, (ii) 20 mg of CBN + 10 mg of CBD, (iii) 20 mg of CBN + 20 mg of CBD, (iv) 20 mg of CBN + 100 mg of CBD, (v) or a placebo.

Three days before the start of the intervention (baseline) and throughout the study, the participants completed a sleep diary within 1 hour of waking. The participants also rated their fatigue 90 minutes before bedtime using a visual analog scale and completed the PROMIS Sleep Disturbance-Short Form at the end of the baseline and intervention periods.

What were the results?

Compared with placebo, CBN taken alone reduced nighttime awakenings and overall sleep disturbances. There were no other differences between the treatment groups and the placebo group.

Anything else I need to know?

There was evidence to suggest a potentially clinically meaningful improvement in sleep quality in the CBN-only group, compared with placebo, but the finding was not statistically significant. The researchers calculated that 75 participants per group would be needed to detect a meaningful effect on sleep quality. It’s possible that an insufficient sample size prevented CBN’s effect on sleep quality from being statistically significant.

A limitation of this study is that sleep quality was only measured subjectively. It would have been helpful to see whether the findings corresponded with objective measures (typically obtained from an actigraphy device worn on the wrist or polysomnography, which uses a polygraph).

At the time of publication, several of the study authors were full-time employees of or investors in companies that manufacture cannabis-related products.

This Study Summary was published on February 2, 2024.