CBN has become one of the most interesting minor cannabinoids in the sleep market. Its reputation began with a simple observation: aged cannabis is often described as sleepier, and aged cannabis contains more CBN. Modern trials have finally begun testing the molecule directly. The results are mixed but not empty. One large trial found improvements in self-reported sleep disturbance, while two others found signals involving awakenings or sleep architecture despite missing their primary endpoints. What they have not yet shown is that the low doses found in many consumer products treat insomnia. This profile sets out where CBN comes from, what it does in the body, what the human trials found, and what remains unproven.
What Is CBN and Where Does It Come From?
CBN was the first cannabinoid ever isolated, at the end of the 19th century, and its structure was worked out in the early 1930s.[1] Unlike THC, CBD or CBG, the plant does not make it on purpose. CBN is a breakdown product. It forms when THC is exposed to heat, light, oxygen and time. In the plant, the acid THCA oxidizes to CBNA, which loses its carboxyl group on heating to become CBN; THC itself oxidizes to CBN directly.[2] Fresh, well-stored flower contains very little of it.
That is why CBN is a marker of age. In a year-long storage study, THCA in a THC-rich chemovar fell by roughly a third at room temperature, and breakdown products including CBN climbed fastest at the warmest storage temperature tested.[2] Old, poorly stored cannabis is high in CBN for the same reason. Our guide to how to store cannabis covers what slows the process, and our decarboxylation explainer covers what heat does to the acid forms.
| Formula | C21H26O2 |
|---|---|
| Molar mass | 310.4 g/mol |
| CAS number | 521-35-7 |
| Melting point | 76–77 °C (169–171 °F) |
| Solubility | Insoluble in water; soluble in ethanol and methanol[3] |
For a broader view on cannabinoids see our complete guide to cannabinoids. For the compound that CBN is often confused with, see our CBG profile.
Is CBN Psychoactive?
Weakly, if at all, at the doses people take. CBN binds the same receptors as THC but more loosely. In cell studies it bound CB1 about two to three times more weakly than THC and CB2 about four times more weakly, and it was about 13 times less potent than THC at CB1 in a signaling assay.[4] In a 1975 study, five men who took 50 mg of CBN by mouth did not report feeling drugged, drunk, dizzy or drowsy, and their heart rate did not rise. When CBN was taken with THC, the volunteers reported feeling more drugged and drowsy than with THC alone, though the authors called the effects small.[5] A 2021 review concluded that most human studies show CBN does not produce cannabis-like effects on its own.[6]
One caveat comes from a 2024 rat study: CBN’s main metabolite, 11-OH-CBN, reached brain concentrations as high as CBN itself and acted at CB1 receptors with potency comparable to THC.[7] Whether that matters at human doses is not known. At 300 mg, far above what products contain, the 2026 insomnia trial recorded mild to moderate side effects but did not report intoxication as a problem.[8]
Can CBN Improve Sleep?
Possibly, but it has not yet been established as an insomnia treatment. “Sedative” may also be the wrong test: the trials suggest CBN could affect sleep maintenance or sleep architecture without producing obvious sedation. Here is the full trail of evidence, from the original observation to the trials.
Where the reputation began. Aged cannabis has a reputation for making people sleepy, and aged cannabis is high in CBN. But aged cannabis also has less THC and a changed terpene profile, so the drowsiness cannot be pinned on CBN from that observation alone.
The 1970s. The Karniol study above is the origin of the “CBN plus THC is more sedating” idea. CBN alone did nothing noticeable; with THC it slightly increased drowsiness.[5] The 2021 review found no published clinical trial at that point that had tested CBN against a validated sleep questionnaire or polysomnography, and it pointed out that products typically contained 5 mg or less, far below any dose ever studied.[6]
The rats. In 2024, University of Sydney researchers recorded sleep in rats given CBN by injection. CBN increased total sleep time, with an effect on non-REM sleep comparable in size to zolpidem, and unlike zolpidem it also increased REM sleep. The injected doses and route used in rats do not translate directly to oral consumer products.[7]
The human trials. Three placebo-controlled trials have now tested CBN on its own for sleep.
| Study | Design | Primary outcome | What else it found, and the limits |
|---|---|---|---|
| Kolobaric et al., 2024[9] | 1,020 adults with disturbed sleep; 25, 50 or 100 mg CBN nightly for four weeks; 4 mg melatonin and placebo groups. Run remotely by a contract research firm; funded by the CBN’s manufacturer. | Sleep-disturbance scores improved most clearly at 50 mg; the paper’s detailed summary described the 25 and 100 mg results as marginal | No significant differences from melatonin were detected, although the trial was not designed to establish that CBN was equivalent to melatonin. No dose beat placebo on the odds of a clinically meaningful improvement, which 42% of the placebo group reached. No objective sleep measures; about 26% gave no follow-up data. |
| Bonn-Miller et al., 2024[10] | 321 randomized, 293 took the product and entered the analysis; adults with poor sleep; 7 nights; 20 mg CBN, alone or with 10, 20 or 100 mg CBD; placebo. Run by Canopy Growth researchers. | Sleep quality: not significant for CBN alone (p = 0.08) | About half an awakening fewer per night and lower sleep-disturbance scores. Adding CBD did not help. All outcomes self-reported. |
| Lavender et al., 2026[8] | 20 adults with insomnia disorder; single night; 30 mg or 300 mg CBN or placebo, crossover, in a sleep lab. | Wake after sleep onset: not significant at either dose | At 300 mg: more stage-2 sleep, fewer arousals, faster sleep onset, better self-rated sleep. 30 mg did nothing. |
Read together, the trials provide limited evidence that CBN may affect some aspects of sleep, but the pattern is inconsistent. A large remote trial with a prespecified sleep-disturbance endpoint found the clearest improvement in self-reported sleep disturbance at 50 mg, with weaker evidence at 25 and 100 mg, though no dose raised the odds of a clinically meaningful improvement, and its remote, subjective design and 26% loss to follow-up remain important limitations.[9] A seven-night trial missed its sleep-quality endpoint but found fewer awakenings and lower sleep-disturbance scores at 20 mg.[10] A small sleep-laboratory trial missed its objective primary endpoint, although 300 mg changed several secondary measures.[8] None tested the 1 to 5 mg doses common in many gummies. The two larger trials were industry-funded or industry-run; the laboratory trial was run by university sleep researchers with Australian government grant support.
That is the same conclusion our review of cannabinoids for sleep reached: CBN is drawing real research interest, and consumer interest has moved faster than the clinical evidence.
What Does CBN Do in the Body?
All of this comes from cells and animals. It describes what CBN can bind to, not what a gummy does.
- CB1 and CB2 receptors (cell studies): CBN binds both, more weakly than THC, and activates signaling through both; it showed no strong preference for either receptor.[4] The older claim that CBN acts “mostly through CB2” is not supported by these numbers.
- Active metabolite (rats): 11-OH-CBN, which the body makes from CBN, is a stronger CB1 agonist than CBN itself and reaches the brain at similar concentrations.[7]
- Sleep architecture (rats): more non-REM and REM sleep at high doses.[7]
How these receptors fit together is covered in our guide to the endocannabinoid system.
What Else Has Been Tested in People?
Beyond the three sleep trials, the other clinical program we found was a topical cream for epidermolysis bullosa, a rare blistering skin disease. According to company-reported results that have not appeared in a peer-reviewed paper, 19 patients in a 2023 phase 2 trial applied a CBN cream to one set of wounds and a control cream to another for 28 days. Itch improved in most patients, but the control cream worked about as well, and the planned statistical tests did not favor the CBN cream. Pain and wound healing could not be analyzed because too few patients had those symptoms. The cream was well tolerated, and the company said it would look for a partner to continue development.[11]
What Is Still Only Preclinical?
The 2017 version of this article listed CBN as an appetite stimulant, antibiotic, ALS medicine, pain reliever, anti-asthmatic, sedative and glaucoma treatment. Each of those claims traces back to a cell or animal study, some of them decades old. Preclinical is not clinical. Here is what each one rests on.
- Appetite (rats): CBN made rats start eating sooner and eat a larger first meal, through CB1 receptors; CBD had the opposite effect.[12]
- Antibacterial (lab): in a 2008 structure–activity study, CBN was among several cannabinoids with potent activity against drug-resistant Staphylococcus aureus in a dish.[13]
- ALS (mice): in mice carrying a human ALS mutation, CBN delivered by implanted pump delayed symptom onset by more than two weeks but did not extend survival.[14]
- Glaucoma (cats): CBN drops lowered eye pressure, more so with repeated dosing, but also caused eye redness, and systemic CBN produced abnormal brain-wave discharges in rats. The authors concluded CBN was toxic to the eye and nervous system in the same way as THC.[15]
- Anti-asthmatic: we could find no study of CBN in asthma or airway models in two literature searches. The bronchodilator work from the 1970s was done with THC. We have removed the claim.
Is CBN Safe?
The short-term human data are reassuring but limited. In the four-week trial, side effects were no more frequent than with placebo; the most common were grogginess, trouble sleeping and headache.[9] The single-night trial recorded only mild to moderate side effects across all arms, and the skin-cream trial reported no serious drug-related events.[8,11] The longest published controlled trial of oral CBN lasted four weeks, so long-term daily safety remains unknown.[9] The cat and rat findings above are a reminder that “non-intoxicating” is not the same as “inert.”
Drug tests. Standard workplace programs ultimately confirm a THC metabolite rather than CBN.[16] However, laboratory research found that CBN cross-reacted with two urine immunoassays used for initial cannabis screening, meaning it could potentially contribute to a preliminary positive result; CBD, CBG and CBC did not.[17] A properly performed confirmatory mass-spectrometry test should distinguish CBN from the THC metabolite. Residual THC in inaccurately labeled or imperfectly purified products remains another practical risk. A recent, batch-specific certificate of analysis can provide evidence of the THC and CBN concentrations, although it is only as reliable as the sampling and testing behind it. Our article on CBG and drug tests explains the same logic for CBG.
How Is CBN Sold, and Is It Legal?
In the United States, most retail CBN is sold as a hemp product, including distillates and isolates used in gummies, tinctures and capsules, usually at 1 to 10 mg per serving and often combined with CBD, THC or melatonin. Because hemp contains very little CBN, most of it is made by converting hemp-derived CBD or THC chemically rather than by extracting it. For how that is done, see our article on synthesized minor cannabinoids.
Hemp-derived CBN has been sold under the 2018 Farm Bill’s definition of hemp, which covers the plant’s cannabinoids as long as delta-9 THC stays under 0.3%. That definition is scheduled to change. On December 11, 2026, the federal hemp redefinition limits final hemp products to 0.4 milligrams of total THC per container and excludes cannabinoids synthesized or manufactured outside the plant. CBN that forms naturally in hemp is one thing; CBN made by converting other cannabinoids in a reactor may fall on the other side of that line. Bills to delay or revise the provision are pending in Congress. Our guide to the 2026 hemp redefinition explains what changes and when. Cannabis-derived CBN follows the rules of the state it is sold in.
What Is the Bottom Line?
CBN is more than a marketing story, but less than a proven sleep medicine. It forms as THC ages, acts weakly at cannabinoid receptors and has not produced a THC-like high in the limited human studies available. Three placebo-controlled trials provide genuine but inconsistent signals: one large industry-funded trial found better self-reported sleep at 25 to 100 mg, while two others missed their primary endpoints but reported improvements in awakenings or aspects of sleep architecture. The low doses found in many gummies remain largely untested. CBN is therefore a plausible and increasingly researched sleep ingredient, not yet an established treatment for insomnia.
References
- Pertwee RG. Cannabinoid pharmacology: the first 66 years. British Journal of Pharmacology. 2006;147(Suppl 1):S163–S171.
- Milay L, et al. Metabolic profiling of cannabis secondary metabolites for evaluation of optimal postharvest storage conditions. Frontiers in Plant Science. 2020;11:583605.
- The Merck Index, entry for cannabinol, via DrugFuture chemical database.
- Rhee MH, Vogel Z, Barg J, Bayewitch M, Levy R, Hanuš L, Breuer A, Mechoulam R. Cannabinol derivatives: binding to cannabinoid receptors and inhibition of adenylylcyclase. Journal of Medicinal Chemistry. 1997;40(20):3228–3233.
- Karniol IG, Shirakawa I, Takahashi RN, Knobel E, Musty RE. Effects of Δ9-tetrahydrocannabinol and cannabinol in man. Pharmacology. 1975;13(6):502–512.
- Corroon J. Cannabinol and sleep: separating fact from fiction. Cannabis and Cannabinoid Research. 2021;6(5):366–371.
- Arnold JC, Occelli Hanbury-Brown C, Anderson LL, Bedoya-Perez M, Udoh M, Sharman LA, Raymond JS, Doohan PT, Ametovski A, McGregor IS. A sleepy cannabis constituent: cannabinol and its active metabolite influence sleep architecture in rats. Neuropsychopharmacology. 2025;50:586–595. Published online November 2024.
- Lavender IG, Marshall NS, McCartney D, et al. Cannabinol for acute treatment of insomnia disorder in a randomized placebo-controlled crossover trial. Journal of Sleep Research. 2026;35(4):e70284.
- Kolobaric A, Saleska J, Hewlings SJ, Bryant C, Colwell CS, D’Adamo CR, Chen J, Pauli EK. A randomized, double-blind, placebo-controlled trial to assess the effectiveness and safety of melatonin and three formulations of Floraworks proprietary TruCBN™ for improving sleep. Pharmaceuticals. 2024;17(8):977.
- Bonn-Miller MO, Feldner MT, Bynion TM, Eglit GML, Brunstetter M, Kalaba M, Zvorsky I, Peters EN, Hennesy M. A double-blind, randomized, placebo-controlled study of the safety and effects of CBN with and without CBD on sleep quality. Experimental and Clinical Psychopharmacology. 2024;32(3):277–284. Published online September 2023.
- InMed Pharmaceuticals. InMed Pharmaceuticals Inc. announces results from a phase 2 clinical trial in epidermolysis bullosa. News release, June 22, 2023.
- Farrimond JA, Whalley BJ, Williams CM. Cannabinol and cannabidiol exert opposing effects on rat feeding patterns. Psychopharmacology. 2012;223(1):117–129.
- Appendino G, Gibbons S, Giana A, Pagani A, Grassi G, Stavri M, Smith E, Rahman MM. Antibacterial cannabinoids from Cannabis sativa: a structure-activity study. Journal of Natural Products. 2008;71(8):1427–1430.
- Weydt P, Hong S, Witting A, Möller T, Stella N, Kliot M. Cannabinol delays symptom onset in SOD1 (G93A) transgenic mice without affecting survival. Amyotrophic Lateral Sclerosis and Other Motor Neuron Disorders. 2005;6(3):182–184.
- Colasanti BK, Craig CR, Allara RD. Intraocular pressure, ocular toxicity and neurotoxicity after administration of cannabinol or cannabigerol. Experimental Eye Research. 1984;39(3):251–259.
- U.S. Department of Transportation. 49 CFR § 40.85: What are the cutoff concentrations for urine drug tests?.
- Kroner GM, Johnson-Davis KL, Doyle K, McMillin GA. Cannabinol (CBN) cross-reacts with two urine immunoassays designed to detect tetrahydrocannabinol (THC) metabolite. Journal of Applied Laboratory Medicine. 2020;5(3):569–574.
Editor’s note: This article was originally published on April 12, 2017, by Cara Wietstock. In October 2026 the editors rebuilt it around the human trials of CBN published since, labeled each preclinical claim by the model it came from, and removed the unsupported anti-asthma claim. This article is for information only and is not medical advice.
Reviewed by Chana Frenkel, PhD.
Last updated October 2026 · Originally published April 12, 2017.
