Updated Research: Sleep, CBN + THC
As a scientist, I continue to question why CBN-containing products have gained such popularity on the cannabis market as a go-to for those looking for a good sleep aid. People in the cannabis industry have been speaking about the sleep-inducing effects of CBN for years, but the basis for their beliefs is hard to pin down. Most people I’ve asked say they’ve read it on a blog post or heard it from a manufacturer of CBN products or just heard it word of mouth. After doing a deep dive reviewing the scientific literature, I haven’t been able to find any credible scientific evidence that CBN will help you get a good night’s sleep. This is what I found.
A 2021 literature review entitled, Cannabinol for Sleep: Separating Fact From Fiction [1] (PMID: 34468204) reported that as of the time of publication there had been no published clinical human trials investigating associations between CBN and sleep using validated sleep questionnaires and/or formal polysomnography. This review found little if any evidence demonstrating that CBN itself elicits sleep-inducing effects in humans and concluded that there was insufficient evidence to support such claims.
So where does the scientific “evidence” come from that has given CBN its sleep-inducing reputation? A study published in 1995 entitled, Synthesis and pharmacological effects in mice of halogenated cannabinol derivatives, has drawn a considerable amount of attention and has been one such study referenced as “evidence” [2] (PMID: 7728937). The fact is that the researchers found that dihalogenated derivatives of CBN (lab-derived changes to CBN’s structure) prolonged the sleep-inducing effects of pentobarbitol. It did not report that CBN itself induced sleep in the mice, but that CBN enhanced sleep when mice were also given a very powerful sedative.
Something else that might have put CBN in the spotlight is a post by the cannabis laboratory, Steep Hill, that hyped CBN on its website by stating, “The consumption of 2.5mg to 5mg of CBN has the same level of sedation as a mild pharmaceutical sedative, with a relaxed body sensation similar to 5 mg to 10 mg of diazepam.” However, Steep Hill later retracted the statement from its website, and further noted, "Initially, it was reported that CBN was a promising adjunct in the treatment of insomnia, but with the advent of a few small trials, sedative qualities have not been observed."
CBN is also being sold in combination with THC to promote sleep. One poorly designed study is routinely referenced as evidence for CBN’s positive effects on sleep which was published in 1975 [3] (PMID: 1221432). Five male volunteers were administered orally the following doses/combinations of CBN and/or THC: 50 mg CBN; 25 mg THC; 12.5 mg THC + 25 mg CBN; or 25 mg THC + 50 mg CBN. The volunteers reported feeling drugged, drunk, dizzy, and drowsy when given THC, but not CBN. With combined THC/CBN treatment, volunteers reported feeling more drugged, drunk, dizzy, and drowsy than when taking THC alone. Again, this does not support the role of CBN as an effective sleeping agent.
In another 1975 report, the effects of THC, CBN and/or CBD on sleep were studied [4] (PMID: 1097148), where volunteers were given 20 mg THC; or 20 mg THC with 40 mg CBN; or 20 mg THC + 40 mg CBD. The researchers found that the combination of THC with CBN produced no detectable changes in the quality, intensity, or duration on sleep compared to the effects of THC on sleep alone. However, the THC-CBD combination tended to delay onset and prolong effects of THC, while making them somewhat more intense, though findings were not statistically significant.
CBN is also being sold in some formulations in combination with CBD as a sleep aid, again with no scientific evidence to back up the combined effectiveness of the two. Findings from a recent clinical trial of CBD, CBN, CBC and melatonin published April 2023 [5] (PMID: 37162192) found no benefit of CBN in the sleep study. The study had 6 arms to it where people were administered various cannabinoid and melatonin combinations (15mg CBD + 15 mg CBN + 5 mg melatonin; 15mg CBD + 15 mg CBN; 15mg CBD; 5 mg melatonin; 15mg CBD Full Spec + 15 mg CBN; and 15mg CBD + 15 mg CBN + 5 mg CBC). The researchers found that all study arms experienced a significant improvement in the PROMIS Sleep Disturbance 8a score from baseline. Among other findings, the researchers found no significant differences in effect between 15 mg CBD and formulations containing 15 mg CBD and 15 mg CBN, alone or in combination with 5 mg CBC. The researchers noted that the lack of additional therapeutic effect from the addition of CBN was noteworthy (using validated sleep measures) since manufacturers of CBN-containing products have been touting the sleep-inducing effects of CBN without sufficient research to support these claims.
What do we make of the current huge influx of CBN products on the market at this time?
Walk into a dispensary and the sleep section is lined with CBN products. When talking to a staff member at an account recently, he told us that the big manufacturers of these products have “educational” trainings that talk about the CBN mechanism at play: THC makes you sleepy; CBN makes you stay asleep for longer.
There is no evidence to back up this claim. The only such evidence appears to be drawn from the 1995 study referenced above in which mice were also given barbiturates and appeared to stay drowsy for longer. The presence of barbiturates is a confounding factor. When examining whether CBN alters the affects of THC to make an individual stay sleep for longer, the recent human clinical trial concluded that there was no such effect. So, in conclusion, there is no scientific basis for all the CBN hype.
We agree that more research is needed on cannabis and the variety of minor cannabinoids including CBN. However, the evidence is pointing to the fact that the mythology surrounding CBN has little scientific basis. The truth is that 50 to 70 million Americans struggle with sleep disorders and CBN provides an easy marketable gimmick to sell to unwary consumers. Various THC-infused products and THC-dominant cultivars have been used for decades and remain — according to the science — the most effective in enhancing sleep. We encourage retailers to look past all the unsupported CBN marketing and focus on findings from the scientific literature which to date provide no evidence that CBN is all that it is cracked up to be.
[1] Cannabinol and Sleep: Separating Fact from Fiction
[2] Synthesis and pharmacological effects in mice of halogenated cannabinol derivatives
H Yoshida 1 , N Usami, Y Ohishi, K Watanabe, I Yamamoto, H Yoshimura
[3] Effects of delta9-tetrahydrocannabinol and cannabinol in man
I G Karniol, I Shirakawa, R N Takahashi, E Knobel, R E Musty
[4] Interactions in man of delta-9-tetrahydrocannabinol. II. Cannabinol and cannabidiol
[5] The Safety and Comparative Effectiveness of Non-Psychoactive Cannabinoid Formulations for the Improvement of Sleep: A Double-Blinded, Randomized Controlled Trial
Jessica Londeree Saleska 1 , Corey Bryant 1 , Antonija Kolobaric 2 , Christopher R D'Adamo 3 , Christopher S Colwell 4 , Derek Loewy 5 , Jeff Chen 1 , Emily K Pauli 1