Cannabinol

Pharmacology & Research

Cannabinol is not really made by the plant so much as left behind by it: CBN forms as THC oxidises with exposure to air, light and heat, so aged or poorly stored cannabis is higher in it. It’s a weak partial agonist at CB1 and at most mildly intoxicating ^{4Reference 4Pertwee RG · 2008ReviewThe diverse CB1 and CB2 receptor pharmacology of three plant cannabinoids: Δ9-tetrahydrocannabinol, cannabidiol and Δ9-tetrahydrocannabivarin — reviewView study →}. Its commercial identity is “the sleep cannabinoid” — but that reputation runs well ahead of the evidence, and pinning down a real hypnotic effect for CBN alone is the central research question here.

1. Sleep

The one human test is a double-blind RCT in 321 adults with poor sleep: 20 mg CBN nightly for a week modestly reduced night-time awakenings and overall sleep disturbance versus placebo, and adding CBD did not improve on CBN alone ^{1Reference 1Bonn-Miller MO et al. · 2024RCTA double-blind, randomized, placebo-controlled study of the safety and effects of CBN with and without CBD on sleep quality — randomised controlled trial (human)View study →}. The effect was small, industry-funded and on self-report. The best objective data are preclinical — a rat polysomnography study found CBN did increase total sleep (both NREM and REM) but in a biphasic pattern, and traced much of the effect to the metabolite 11-hydroxy-CBN, a far more potent CB1 agonist than CBN itself ^{2Reference 2Arnold JC et al. · 2025AnimalA sleepy cannabis constituent: cannabinol and its active metabolite influence sleep architecture in rats — rat polysomnography modelView study →}.

Gap: one small subjective human RCT plus rodent data — enough to suggest a real but modest effect, not the strong sedation CBN is marketed for, and the historical “sedative” lore came largely from THC-contaminated samples and THC-combination animal work, where CBN alone was weakly active ^{2,5Reference 2Arnold JC et al. · 2025AnimalA sleepy cannabis constituent: cannabinol and its active metabolite influence sleep architecture in rats — rat polysomnography modelView study →Reference 5Takahashi RN · 1975AnimalPharmacologic interaction between cannabinol and Δ9-tetrahydrocannabinol — animal modelView study →}.

2. Appetite stimulation

In satiated rats, oral CBN produced a CB1-receptor-mediated increase in appetite — shorter latency to feed and larger, longer meals — the mirror image of CBD’s appetite-suppressing effect ^{3Reference 3Farrimond JA et al. · 2012AnimalCannabinol and cannabidiol exert opposing effects on rat feeding patterns — rat modelView study →}.

Gap: rodent feeding behaviour only; no human appetite data ^{3Reference 3Farrimond JA et al. · 2012AnimalCannabinol and cannabidiol exert opposing effects on rat feeding patterns — rat modelView study →}.

Mechanisms

Target / pathway	Effect	Relevant to
Weak CB1 partial agonism	mild psychoactivity, appetite	appetite, sleep
Metabolism to 11-hydroxy-CBN (potent CB1 agonist)	likely carries much of the sedative effect	sleep
THC oxidation product	accumulates with age of the material	—

Clinical trials

CBN has a single completed sleep RCT and little else; interest is largely commercial, ahead of the clinical evidence.

Last checked: July 2026.

Toxicity & Safety

CBN is mildly active and regarded as well tolerated, with drowsiness the most commonly described effect. Because human study is minimal, its full safety profile and drug-interaction potential are not established — and since its effects appear partly mediated by a CB1-active metabolite, caution with other sedatives is sensible. Commercial CBN products vary in purity and labelled content, and some “CBN” on the market is simply aged/degraded THC material.

Dosage

The only human dose with any evidence behind it is the 20 mg nightly used in the sleep RCT ^{1Reference 1Bonn-Miller MO et al. · 2024RCTA double-blind, randomized, placebo-controlled study of the safety and effects of CBN with and without CBD on sleep quality — randomised controlled trial (human)View study →} — a single, small, industry-funded study, so this is a studied dose, not a recommendation. No dose is established for any other use, and animal doses do not translate to humans.

References

1. Bonn-Miller MO, Feldner MT, Bynion TM, et al. (2024). A double-blind, randomized, placebo-controlled study of the safety and effects of CBN with and without CBD on sleep quality — randomised controlled trial (human). Experimental and Clinical Psychopharmacology. https://pubmed.ncbi.nlm.nih.gov/37796540/
2. Arnold JC, Occelli Hanbury-Brown CV, Anderson LL, et al. (2025). A sleepy cannabis constituent: cannabinol and its active metabolite influence sleep architecture in rats — rat polysomnography model. Neuropsychopharmacology. https://pubmed.ncbi.nlm.nih.gov/39528623/
3. Farrimond JA, Whalley BJ, Williams CM (2012). Cannabinol and cannabidiol exert opposing effects on rat feeding patterns — rat model. Psychopharmacology (Berl). https://pubmed.ncbi.nlm.nih.gov/22543671/
4. Pertwee RG (2008). The diverse CB1 and CB2 receptor pharmacology of three plant cannabinoids: Δ9-tetrahydrocannabinol, cannabidiol and Δ9-tetrahydrocannabivarin — review. British Journal of Pharmacology. https://pubmed.ncbi.nlm.nih.gov/17828291/
5. Takahashi RN, Karniol IG (1975). Pharmacologic interaction between cannabinol and Δ9-tetrahydrocannabinol — animal model. Psychopharmacologia. https://pubmed.ncbi.nlm.nih.gov/168604/