CBN vs CBD: Differences, Effects and Sleep Evidence

CBN vs CBD in short: CBN (cannabinol) forms when THC breaks down as cannabis ages, and it acts weakly on the brain's CB1 receptor; CBD (cannabidiol) is made by the living plant and is not intoxicating. CBD is also the only one of the two approved as a medicine: a purified CBD is prescribed for rare seizure disorders [1]. CBN is sold mainly as a sleep aid, but the human trials so far are small and their results mixed [2][3][4]. This page sets out where each compound comes from, how they differ in the body and what the studies actually measured.

CBN vs CBD at a glance

	CBN (cannabinol)	CBD (cannabidiol)
How it forms	A breakdown product: THC oxidises into CBN as cannabis ages in air [5]	Made by the plant with an enzyme, CBDA synthase; heat then turns CBDA into CBD [6]
Where it is found	Old or poorly stored cannabis [5]	Fresh plants, most of all fibre-type (hemp) cannabis [6]
CB1 receptor	Binds, with about a tenth of the affinity of THC [5]	Binds weakly and acts mostly through other targets [7]
Intoxicating?	Mild at most; older human studies mostly found no cannabis-like effect [2]	No; a WHO committee found no abuse or dependence potential [8]
Approved medicine	None	Purified CBD (Epidiolex) for seizures in Lennox-Gastaut syndrome, Dravet syndrome and tuberous sclerosis complex [1]
Best human evidence	Two recent sleep trials with small or mixed results [3][4]	Randomised trials in severe childhood epilepsy [9]
Known risks	Little studied	Liver injury, drug interactions, drowsiness [1]

Where CBN and CBD come from

Both compounds come from the resin of the cannabis plant, but by different routes. The plant builds CBD's acid form, CBDA, with an enzyme called CBDA synthase, and this enzyme is what makes fibre-type (hemp) plants rich in CBD [6]. Heat turns CBDA into CBD, the same decarboxylation step that turns THCA into THC (see the decarboxylation chart).

CBN has no enzyme of its own. It is a breakdown product: THC exposed to air oxidises and slowly becomes CBN, which is why old or carelessly stored cannabis holds more CBN and less THC [5]. CBN was the first cannabinoid to be isolated, from hashish in the late 19th century [5]. The CBN guide covers how it forms in more detail.

How CBN and CBD act in the body

THC produces its high mainly through the CB1 receptor in the brain. CBN binds the same receptor, but with about a tenth of THC's affinity [5]. That is why CBN is often called mildly psychoactive, although the human studies of its effects are old and small, and most found no clear cannabis-like effect from CBN alone [2].

CBD binds the CB1 and CB2 receptors only weakly and works through other targets; in laboratory studies it can even dampen the action of compounds that switch those receptors on [7]. In 2018 a World Health Organization expert committee found that CBD is not psychoactive and has no potential for abuse or dependence [8]. For the more familiar pairing, see THC vs CBD.

CBN vs CBD for sleep: what the trials show

Sleep is the main reason CBN is sold. A 2021 review of the human research found it dated and limited, mostly small studies from the 1970s and 1980s, and concluded that there was not enough published evidence to support sleep claims [2]. The same review noted that sleep products then contained about 5 mg of CBN or less [2]. Two randomised trials have reported since:

• 2024: 293 adults with poor sleep took 20 mg of CBN, CBN combined with CBD, or a placebo for seven nights. CBN alone reduced the number of awakenings and overall sleep disturbance, but its effect on the main outcome, sleep quality, was not statistically significant. Adding CBD did not improve the results [3].
• 2026: 20 adults with insomnia disorder took a single dose of 30 mg or 300 mg of CBN, or a placebo, in a sleep laboratory. Neither dose changed the main outcome, time spent awake after falling asleep. At 300 mg people fell asleep faster and rated their sleep better, and the authors called for larger, longer trials [4].

For CBD, the clearest link to sleep comes from its side effects: drowsiness is among the common side effects of the prescription product [1][9]. That is not evidence that CBD treats insomnia. The doses above describe study conditions, not an amount to take. The wider picture is on the cannabis and sleep page.

CBD as a medicine: the epilepsy evidence

CBD's strongest evidence is in two severe childhood epilepsies. In a 2017 trial of 120 children and young adults with Dravet syndrome, the median number of convulsive seizures per month fell from 12.4 to 5.9 with CBD, against 14.9 to 14.1 with placebo [9]. The FDA approved a purified CBD medicine, Epidiolex, in 2018; it is used for seizures in Lennox-Gastaut syndrome, Dravet syndrome and tuberous sclerosis complex [1]. Shop CBD oils are not the same product, as the page on CBD and epilepsy explains. CBN has no approved medical use.

Side effects and safety

In the Dravet trial, side effects that were more common with CBD than with placebo included diarrhoea, vomiting, fatigue, fever, drowsiness and abnormal liver tests [9]. The FDA warns that CBD can cause liver injury and can change how other medicines work [1]. CBN's safety has been studied far less: the trials above lasted between one night and one week [3][4]. Anyone who takes other medicines should ask a doctor or pharmacist before using either compound.

Can CBN and CBD be combined?

Many products combine the two. The one trial that tested the combination found that adding 10, 20 or 100 mg of CBD to 20 mg of CBN did not improve sleep results over CBN alone [3]. Claims that the two work better together rest more on theory, such as the entourage effect, than on measurement.

Frequently asked questions

Is CBN stronger than CBD?

They do not sit on one scale. CBN binds the CB1 receptor with about a tenth of THC's affinity [5] and is at most mildly psychoactive, while CBD is not intoxicating [8]. For sleep, neither has a proven effect.

Is CBN or CBD better for sleep?

Neither is proven. A 2024 trial found that 20 mg of CBN reduced night-time awakenings but did not significantly improve the main sleep quality score [3], and a 2026 trial found no change in time awake after sleep onset [4]. CBD lists drowsiness as a side effect but is not an approved sleep treatment [1].

Does CBN get you high?

Not like THC. Its affinity for the CB1 receptor is about a tenth of THC's [5], and most older human studies found no clear cannabis-like effect from CBN alone [2].

Is CBN just old THC?

Largely, yes. CBN forms when THC oxidises in air, so old or poorly stored cannabis contains more CBN and less THC [5].

Why is CBD an approved medicine and CBN not?

CBD has large randomised trials in severe epilepsy, which led to the 2018 FDA approval of a purified CBD medicine [9][1]. CBN has only small trials so far [2][4].

Sources

1. US Food and Drug Administration. What you need to know (and what we are working to find out) about products containing cannabis or cannabis-derived compounds, including CBD. Consumer update. fda.gov
2. Corroon J. Cannabinol and sleep: separating fact from fiction. Cannabis and Cannabinoid Research. 2021;6(5):366-371. doi:10.1089/can.2021.0006
3. 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. doi:10.1037/pha0000682
4. Lavender IG, Marshall NS, McCartney D, Cho G, Irwin C, Suraev A, Gordon R, Arnold JC, D'Rozario AL, Gordon CJ, Saini B, Sivam S, Zheng Y, Grunstein RR, Yee BJ, McGregor IS, Hoyos CM. Cannabinol for acute treatment of insomnia disorder in a randomized placebo-controlled crossover trial. Journal of Sleep Research. 2026;35(4):e70284. doi:10.1111/jsr.70284
5. Maioli C, Mattoteia D, Amin HIM, Minassi A, Caprioglio D. Cannabinol: history, syntheses, and biological profile of the greatest "minor" cannabinoid. Plants. 2022;11(21):2896. doi:10.3390/plants11212896
6. Taura F, Sirikantaramas S, Shoyama Y, Yoshikai K, Shoyama Y, Morimoto S. Cannabidiolic-acid synthase, the chemotype-determining enzyme in the fiber-type Cannabis sativa. FEBS Letters. 2007;581(16):2929-2934. doi:10.1016/j.febslet.2007.05.043
7. Pertwee RG. The diverse CB1 and CB2 receptor pharmacology of three plant cannabinoids: delta-9-tetrahydrocannabinol, cannabidiol and delta-9-tetrahydrocannabivarin. British Journal of Pharmacology. 2008;153(2):199-215. doi:10.1038/sj.bjp.0707442
8. World Health Organization. News briefing: 40th WHO Expert Committee on Drug Dependence. 13 September 2018. who.int
9. Devinsky O, Cross JH, Laux L, Marsh E, Miller I, Nabbout R, Scheffer IE, Thiele EA, Wright S. Trial of cannabidiol for drug-resistant seizures in the Dravet syndrome. New England Journal of Medicine. 2017;376(21):2011-2020. doi:10.1056/NEJMoa1611618

Related: CBN, the hidden gem of the cannabinoids, CBD (cannabidiol), THC vs CBD and the entourage effect.

Educational information about two cannabinoids. Not medical advice, not a dosing guide and not a product review.