A small CBD sleep study found that regular users of CBD (cannabidiol) users had longer sleep and more REM (rapid eye movement) on their wearables. By monitoring participants' sleep on these wearables, researchers were able to find a link, not a cause and effect, between CBD consumption and sleep. The study raises the much-discussed question: does CBD actually help with sleep?

What Were the CBD Sleep Study's Findings?

The study monitored 20 participants, 9 of whom were CBD users and 11 non-CBD-users. Researchers equipped the participants with wearable devices, similar to an Apple Watch, to capture 72 hours of data during their everyday life. These were their findings:

Figures from a 72-hour wearable study of 20 people looking at CBD use and sleep. This is an observational comparison; therefore, it shows an association. It does not show that CBD caused the differences.

Researchers found that CBD users averaged about 104 minutes more sleep than non-users, and that CBD users were in bed about 116 minutes longer. REM sleep, where the most vivid dreaming occurs, was 58 minutes longer in CBD users than in non-users. CBD users' peak heart rate was about 29 bpm lower than in non-users. Some measurements found no differences in their findings, such as resting and average heart rate and the amount of time awake.

How Did the Study Define “Regular CBD User”?

To understand the implications of this study, it is important to understand how it defines a "regular CBD user". The study considered participants who used at least 20mg of CBD orally, at least twice a week, to be regular CBD users. We must note here that this is the study's definition, not a recommended amount. We note that in the UK, the FSA guidance for healthy adults is lower; they recommend a 10mg CBD daily dosage limit. A 30ml bottle of 250mg CBD oil meets the CBD dosages set by both this study and the FSA daily guidance.

Does This Mean CBD Improves Sleep?

No, it can't tell us that.

The researchers watched participants as they already were, and did not control when they started or stopped using CBD. They simply gathered a group of people, 9 who already used CBD and 11 who didn't. This type of research can show that two things go together, but it doesn't mean that one caused the other.

A controlled trial would be able to discover an actual link between sleep and CBD. In a controlled trial, researchers choose who gets what – participants are randomly split into a group that takes CBD and a group that takes a placebo (an identical-looking product that contains zero CBD). A double-blind approach would be taken, meaning that nobody knows who's taking the real CBD and who's taking the placebo, including the researchers. Because the split is random, the groups should be more alike in other ways, so differences in sleep could be pinned down to the CBD.

Some of the study's findings could be caused by CBD; however, they could also be caused by outside factors:

• Fitness and exercise: some participants may have exercised less intensely during the 72-hour period, which would result in having a lower peak heart rate.

• Daily routines: the CBD group spent about 2 hours longer in bed, which could have been caused by those users having more flexible schedules such as students or shift workers on days off.

• Lifestyle: CBD users may have more of a tendency to pay more attention to sleep, diet or wellbeing generally.

• Other supplements: the study did not factor in the possibility that participants could have taken other supplements known to affect sleep, such as caffeine.

With such a small sample size (20 people), one or two individuals with unusual habits can significantly shift the averages a lot. We'll dig deeper into what better evidence would look like a few paragraphs down.

Why Was Peak Heart Rate Lower in CBD Users?

While resting and average heart rate were similar between the two groups, peak heart rate differed. Peak heart rate is closely influenced by how hard people exercise, and in this study, exercise was not standardised. This particular finding isn't evidence of a heart health benefit.

Do Wearables Accurately Measure Sleep Data?

Wearables like a Fitbit or Apple Watch are great for everyday use and can help estimate sleep stages and REM figures; however, they do not measure to the same degree of accuracy as a sleep laboratory. These wearables can effectively spot trends in your own habits, but cannot be used clinically for diagnosing anything. The Cleveland Clinic Journal of Medicine mentions that sleep trackers are inaccurate at distinguishing sleep stages compared with a lab sleep test (polysomnography).

What Would Better CBD and Sleep Evidence Look Like?

Much better findings could be found in a study that conducted randomised, placebo-controlled trials with larger groups and longer tracking periods. Better handling of how the CBD is being administered would improve the findings too, such as measured and verified doses and products, rather than self-reported use. Studies like this can serve as inspiration for other researchers to carry out even better trials, as more research is needed.

What Should You Know Before Trying CBD?

Always consult your GP before taking any medication or health supplement like CBD, especially if you are pregnant, breastfeeding or have ongoing sleep problems. We highly recommend checking for third-party lab reports and sticking to the UK FSA guidance when it comes to selecting a CBD product or brand and starting a dosing regimen. You can browse our range of CBD Oils that have all had their Novel Foods applications filed and come with third-party lab testing, or see the wider CBD for sleep range.

Although no big claims can be made from this CBD sleep study, it is still interesting. Among a small group of people, regular CBD users had longer sleep and more REM time on their wearable devices. Its shortcomings are that, with 20 people, 72 hours of data and no way to separate cause from coincidence, it doesn't concretely answer the question: does CBD help with sleep? Larger, controlled trials are needed before we can draw any conclusions.