Cannabinol (CBN)

6,6,9-trimethyl-3-pentylbenzo[c]chromen-1-ol

Overview

Cannabinol (CBN) belongs to Cannabinoids.

Key safety note: CBN is only mildly psychoactive and, in the limited human data available, appears well tolerated, but robust safety data are lacking, and most evidence comes from preclinical work or from THC-containing cannabis rather than CBN alone.[3][2]
Effects
Subjective effects vary. What a substance feels like depends on dose, individual physiology, mindset, and setting. The points below describe commonly reported effects, not guaranteed, uniform, or desirable outcomes.
  • Mildly psychoactive: far weaker than THC. Only large doses produce intoxication, and CBN alone typically produces little noticeable effect.
  • Popularly sold for sleep/sedation, but controlled human evidence for a hypnotic effect of CBN alone is lacking.
  • Sedation historically attributed to CBN more likely reflected residual THC in aged cannabis.
Dosing & duration
Harm-reduction note: These are commonly cited reference ranges, not a recommendation or a “safe” dose. Potency, purity, body chemistry, tolerance, and drug combinations vary widely. Start low, go slow, wait for full effects before redosing, and never assume an unknown product matches these figures. Missing data is not evidence of safety.

Not reported

Dose ranges

Duration

Chemical & Physical Properties
FormulaC21H26O2
Molar mass310.4 g/mol
StateNot reported
Melting point76–77 °C (NTP, 1992)
Boiling point185 °C at 0.05 mmHg (NTP, 1992)
DensityNot reported
Vapor pressureNot reported
pKaNot reported
LogP6.1 (predicted, XLogP3)
SolubilityNot reported
Refractive indexNot reported
Identifiers & Synonyms
CAS521-35-7
CAS (enantiomer)
PubChem CID2543
InChIKeyVBGLYOIFKLUMQG-UHFFFAOYSA-N
InChIInChI=1S/C21H26O2/c1-5-6-7-8-15-12-18(22)20-16-11-14(2)9-10-17(16)21(3,4)23-19(20)13-15/h9-13,22H,5-8H2,1-4H3
SMILESCCCCCC1=CC(=C2C(=C1)OC(C3=C2C=C(C=C3)C)(C)C)O

Synonyms

  • CBN
  • Cannabinol
Pharmacodynamics & Biochemistry

Cannabinol (CBN) is a mildly psychoactive phytocannabinoid that, uniquely among the major cannabinoids, is not made enzymatically by the plant but forms by oxidative degradation of THC on exposure to heat, light and oxygen, so it accumulates in aged or poorly stored cannabis. It is only weakly intoxicating: much larger doses than THC are needed to produce any psychoactive effect. At the cannabinoid receptors CBN is a low-affinity partial agonist. It binds CB1 several-fold (≈5–10×) more weakly than THC (CB1 Ki reported ≈200–560 nM), and unusually it binds CB2 with somewhat greater affinity than CB1, giving it a modest CB2 bias: the opposite of THC's CB1 preference. This weak CB1 agonism is why aged, CBN-rich cannabis is far less intoxicating than fresh material. CBN is widely marketed as a 'sleep cannabinoid', but this reputation is poorly supported. The idea traces to old observations that aged cannabis felt more sedating, yet that cannabis also still contained THC. A 2021 review (Corroon) concluded there is no good controlled human evidence that CBN alone is sedating, and that the historic sedation was more plausibly due to residual THC. CBN on its own appears to produce little systemic effect. Beyond the cannabinoid receptors CBN modulates several TRP channels (a TRPA1/ANKTM1 agonist and a low-affinity agonist at TRPV1–4) and blocks voltage-gated sodium channels (Nav1.7, Nav1.8): an emerging non-intoxicating analgesic interest. It is highly lipophilic and hepatically metabolised by CYP2C9 and CYP3A4. Its main metabolite 11-OH-CBN is reportedly about twice as potent as CBN. Human pharmacokinetic data are limited.

Biological targets

  • CB1
  • CB2

Binding & functional measurements

TargetMeasurementSpecies
CB1 receptorKi 285 nMHuman
CB1 receptorEC50 307 nMHuman
CB2 receptorEC50 289 nMHuman
CB2 receptorKi 163 nMHuman
Pharmacokinetics
BioavailabilityNot well characterised, highly lipophilic with poor/variable oral absorption, like other cannabinoids
TmaxNot reported
Half-lifeNot established in humans
VdNot reported
Protein bindingNot reported
MetabolismHepatic, CYP2C9 & CYP3A4. Active metabolite 11-OH-CBN (~2× potency)
ExcretionNot reported
Toxicology & Safety
Harm-reduction note: Toxicity and risk depend on dose, route, purity, combinations, setting, and individual health factors. Missing harms should never be interpreted as evidence of safety.

Not reported

CBN is only mildly psychoactive and, in the limited human data available, appears well tolerated, but robust safety data are lacking, and most evidence comes from preclinical work or from THC-containing cannabis rather than CBN alone. Its popular reputation as a sleep aid is not established by controlled trials. Marketed CBN products (gummies, oils, 'nighttime' tinctures) are unregulated supplements of variable quality and content. Some are made by chemically converting CBD and may carry residual THC or synthesis by-products. No CBN product is an approved medicine.[3][2]

Legal Status
Legal note: Legal status can change over time and may vary by country, region, formulation, analogue status, prescription context, and enforcement practice. Always confirm with current official sources before relying on this section.
Interactions & Contraindications

Drug interactions

Drugs cleared by shared CYP enzymes (e.g. CYP2C9, CYP3A4) As a cannabinoid it may interact with CYP2C9 and CYP3A4 substrates, though human data are sparse.[2]
Alcohol, Benzodiazepines Plausible additive sedation and CNS depression, especially in THC-containing products.[3]

Contraindications

Pregnancy or breastfeeding insufficient safety data.[2]
Combining with alcohol or other CNS depressants caution with sedatives, alcohol and other CNS depressants.[3]
Known hypersensitivity to the drug hypersensitivity to cannabinoids.[2]
Usage & Context
  • Sold as a mildly-/non-intoxicating cannabinoid supplement, heavily marketed for sleep, CBN gummies, oils and 'nighttime' tinctures, despite limited evidence.
  • A subject of preclinical research for analgesic (Nav-channel), anti-inflammatory, appetite-stimulating and neuroprotective effects: none approved or confirmed in humans.
  • Forms naturally as cannabis ages, and is used analytically as a marker of cannabis age/degradation.
Sources & Evidence

Further Information