Cannabinol (CBN) has long been seen as a less interesting cannabinoid in the shadow of THC and CBD. It forms when THC breaks down, for example when cannabis is stored for a long time, and was for years regarded mostly as a by-product. In recent years, however, several research groups have started to look at how CBN affects sleep, both in animal studies and in studies on people.
Update 2026: In February 2026, the first study to measure the effect of CBN on the sleep of people with diagnosed insomnia objectively, in a sleep laboratory, was published. The results were mixed, and we have added them further down in this article.
At a glance
- CBN forms when THC oxidises and breaks down.
- In a 2024 rat study, CBN led to longer total sleep time and more deep sleep and REM sleep.
- In a 2022 human study, people given CBN woke up fewer times per night than those given placebo.
- A 2026 study in people with insomnia found no difference in time spent awake during the night, although some other sleep measures improved.
- The research is still at an early stage.
What is CBN?
CBN is a so-called minor cannabinoid. Fresh cannabis contains only small amounts, but levels rise when THC is exposed to air, light and heat over time. CBN acts much more weakly on the body’s CB1 receptors than THC does. You can read more about how CBN differs from CBD in our article CBN vs CBD.
The animal study: more deep sleep and REM sleep
One of the most talked-about contributions comes from the University of Sydney. The researchers measured sleep in rats using polysomnography, the same kind of recording of brain and muscle activity used in sleep laboratories for people.
- CBN increased total sleep time, although sleep first dipped slightly before rising clearly.
- Both NREM sleep (deeper sleep) and REM sleep increased.
- The effect on NREM sleep was of a similar size to that of the sleep medication zolpidem.
The researchers also found that the breakdown product 11-hydroxy-CBN reached brain levels as high as CBN itself. It acted on CB1 receptors about as strongly as THC and also influenced sleep. This may mean that part of the effect of CBN comes from this metabolite.
The 2022 study: fewer night-time awakenings
In a double-blind, placebo-controlled study carried out in 2022, adults who rated their own sleep as poor received either placebo, 20 mg of CBN, or 20 mg of CBN combined with different amounts of CBD. They took the product for seven nights in a row, and the analysis included 293 participants.
The group that received CBN alone woke up fewer times per night and reported less overall sleep disturbance than the placebo group. The improvement in perceived sleep quality, however, was not statistically significant. There was no difference in how quickly participants fell asleep, how long they were awake during the night or how tired they felt the next day. Adding CBD did not strengthen the effect.
The study relied on the participants’ own reports rather than measurements in a sleep laboratory.
The 2026 study: the first sleep laboratory measurements
In February 2026, a study from the Woolcock Institute of Medical Research in Sydney was published. Twenty adults with insomnia diagnosed by a doctor received a single dose of 30 mg CBN, 300 mg CBN or placebo on three separate nights. Their sleep was measured with polysomnography.
The main measure, how long participants were awake after first falling asleep, was not affected by either dose. The higher dose did, however, lead to slightly more light deep sleep (NREM-2), a shorter time to fall asleep, fewer brief arousals in brain activity and better perceived sleep quality. The researchers stress that larger and longer studies are needed.
How might CBN affect sleep?
Exactly how CBN works is not yet mapped out. The main hypotheses the researchers put forward are that CBN, and especially its metabolite 11-hydroxy-CBN, acts on CB1 receptors in the brain, and that CBN may also interact with other signalling systems. More research is needed to work out what role each mechanism plays.
Good to know
Results from animal studies cannot be transferred directly to people, and the human studies so far are few and partly small. The study that measured sleep most precisely found no effect on its main measure. Researchers agree that larger and longer studies are needed before any firm conclusions can be drawn about CBN and sleep.
What is CBN?
CBN, or cannabinol, is a cannabinoid that forms when THC breaks down, for example during long storage. It acts much more weakly on CB1 receptors than THC.
What does the research say about CBN and sleep?
In animal studies, CBN led to longer sleep and more deep sleep and REM sleep. In people there are early results showing fewer awakenings, but a 2026 study found no effect on time spent awake during the night.
How does CBN differ from CBD when it comes to sleep?
CBD has been studied more, including in relation to stress and sleep. CBN is less explored, and in the 2022 study CBD did not strengthen the effect of CBN.
What doses were used in the studies?
The 2022 study used 20 mg of CBN each evening for seven nights. The 2026 study used a single dose of 30 mg or 300 mg. These doses describe the studies and are not recommendations.
Is this medical advice?
No. This article summarises research and should not replace medical advice. Talk to a healthcare professional if you have sleep problems.
This article summarises scientific research and is intended for general information only. It is not medical advice and should not be used to make a diagnosis or choose a treatment. Always consult a doctor or other healthcare professional.
Sources
- Arnold JC, Occelli Hanbury-Brown CV et al. (2025). A sleepy cannabis constituent: cannabinol and its active metabolite influence sleep architecture in rats. Neuropsychopharmacology, 50(3), 586–595.
- Bonn-Miller MO, Feldner MT et al. (2024). 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, 32(3), 277–284.
- Lavender IG, Marshall NS, McCartney D et al. (2026). Cannabinol for Acute Treatment of Insomnia Disorder in a Randomized Placebo-Controlled Crossover Trial. Journal of Sleep Research, 35(4), e70284.
