Cannabinol (CBN) for Sleep: Current Evidence and Recommendations
CBN shows modest effectiveness for improving sleep quality and reducing nighttime awakenings, but current evidence does not support it as superior to established first-line treatments like cognitive behavioral therapy for insomnia (CBT-I) or even low-dose melatonin.
Evidence Quality and Limitations
The available evidence for CBN consists entirely of recent industry-sponsored trials with significant methodological limitations:
No guideline support exists for CBN use in sleep disorders. Major sleep medicine guidelines from NCCN, American Academy of Sleep Medicine, and systematic reviews do not mention CBN as a treatment option 1.
The most rigorous recent trial (2024) found that 20 mg CBN reduced nighttime awakenings and overall sleep disturbance compared to placebo, but showed no improvement in sleep onset latency, wake after sleep onset, or daytime fatigue 2.
A large comparative effectiveness trial (2024) demonstrated that 15 mg CBD with or without 15 mg CBN showed no significant advantage over 5 mg melatonin alone for sleep disturbance 3.
Another 2024 trial found all CBN doses (25 mg, 50 mg, 100 mg) improved sleep quality similarly to 4 mg melatonin, with no dose-response relationship and no superiority over melatonin 4.
Recommended Treatment Algorithm
First-Line Interventions (Strongly Recommended)
Start with evidence-based non-pharmacological approaches:
Cognitive Behavioral Therapy for Insomnia (CBT-I) is the gold standard, showing superiority over benzodiazepines and non-benzodiazepine medications in head-to-head trials 1.
Sleep hygiene education: Regular morning/afternoon exercise, daytime bright light exposure, keeping sleep environment dark and quiet, avoiding heavy meals, alcohol, and nicotine near bedtime 1.
Stimulus control and sleep restriction therapy as recommended by the American Academy of Sleep Medicine 5.
Second-Line Pharmacological Options (If Behavioral Interventions Insufficient)
Before considering CBN, use established agents:
Short-acting benzodiazepines (lorazepam) or non-benzodiazepines (zolpidem 5 mg for immediate-release) for short-term use 1.
Low-dose sedating antidepressants (trazodone, mirtazapine, doxepin) for persistent sleep maintenance issues 1, 5.
Melatonin 4-5 mg has equivalent efficacy to CBN based on direct comparison trials 3, 4.
CBN Consideration (Experimental/Alternative Option)
If patients specifically request CBN or have failed conventional therapies:
Dosing: 20-25 mg nightly appears optimal based on available data; higher doses (50-100 mg) show no additional benefit 4, 2.
Expected effects: Modest reduction in nighttime awakenings and overall sleep disturbance, but no improvement in sleep onset latency or daytime function 2.
Safety profile: Generally well-tolerated with minimal side effects (12% reporting any side effect, none severe) 3.
Duration: Evidence limited to 4-7 weeks of use; long-term safety unknown 3, 4, 2.
Critical Caveats
Major limitations that should inform patient counseling:
Insufficient evidence for routine clinical use per systematic reviews of cannabinoid therapies for sleep disorders 6.
No superiority over melatonin, which is less expensive and has more established safety data 3, 4.
Adding CBD to CBN provides no additional benefit and may not be worth the added cost 3, 2.
Lack of FDA approval for sleep indications; all available products are unregulated supplements with variable quality control.
Unknown long-term effects, drug interactions, and potential for dependence have not been adequately studied 6.
Essential Diagnostic Workup Before Any Sleep Treatment
Rule out primary sleep disorders that require specific interventions:
Screen for obstructive sleep apnea using STOP questionnaire if excessive sleepiness, snoring, or observed apneas present; treat with CPAP/BiPAP, not sedatives 1.
Check ferritin levels if restless legs syndrome suspected (treat if <45-50 ng/mL with dopamine agonists or gabapentin) 1.
Evaluate for depression, anxiety, pain, and medication side effects as treatable causes of insomnia 1.
The evidence strongly favors established behavioral and pharmacological interventions over CBN, which should be considered experimental at best and certainly not a first-line option.