“Sweet sleep! Like pure happiness, you come most willingly when unbidden and unbesought.”
Johann Wolfgang von Goethe, “Roman Elegies” (1795)
Sleep disorders are among the most common health problems of our time. Conventional sleeping pills often come with significant risks of dependence and sometimes serious side effects, so many people affected look for natural alternatives. The natural cannabinoid cannabidiol (CBD), which can also be extracted from industrial hemp, is increasingly becoming a focus of research. But what do recent scientific studies actually show about CBD and sleep disorders?
How does CBD act in the brain, and what does that mean for sleep?
To understand possible links between CBD and sleep, it helps to look first at how it works. CBD interacts with the body's own endocannabinoid system, which is involved, among other things, in regulating the sleep-wake cycle. Unlike psychotropic (temporarily mind-altering) delta-9-THC, however, CBD binds only weakly to the CB1 receptors of the endocannabinoid system, but it influences many other receptor systems in the body. Here is a short overview of the known mechanisms being studied in connection with sleep:
1. Modulation of the endocannabinoid system: CBD raises the level of the body's own cannabinoid anandamide (AEA) by inhibiting FAAH (fatty acid amide hydrolase), the enzyme that breaks it down. Researchers are investigating whether higher anandamide levels are linked to more deep sleep. A systematic review by Peng et al. (2022) (2) in Basic & Clinical Pharmacology & Toxicology describes a possible link between this FAAH inhibition and sleep parameters, particularly sleeping through the night.
2. Effect on the adenosine pathway: One mechanism of particular interest for sleep involves the adenosine system. Adenosine is a messenger that builds up gradually while you are awake, creating sleep pressure and signalling tiredness. By inhibiting adenosine reuptake, CBD might influence this natural mechanism (4).
3. GABA modulation: CBD also interacts with GABA-A receptors, the main inhibitory neurotransmitter receptors in the brain. At higher doses, CBD can increase GABA activity. Since GABA dampens the excitability of nerve cells, this mechanism is being studied mainly in connection with sleeping through the night (5).
4. Serotonin receptors, anxiety and mood: CBD interacts with serotonin receptors, which play a role in regulating anxiety and mood. Because sleep problems often go hand in hand with anxiety and anxiety disorders, researchers are examining whether some of the effects observed on sleep come about this way. A systematic review by Blessing et al. (2015) (1) in the journal Neurotherapeutics describes these connections in detail.
These different mechanisms may explain why research focuses mainly on sleep problems linked to stress and anxiety. In primary sleep disorders without a psychological component, the observed effects appear less pronounced.
What recent studies say about CBD and sleep quality
Two observations up front:
1. The natural cannabinoid CBD cannot be patented (much like melatonin), so there is no pharmaceutical funding for the very costly randomised controlled trials (RCTs) that are generally considered the highest level of evidence. This explains gaps in the evidence. Preclinical research (e.g. animal models) provides plausibility, but human data are limited and do not guarantee effectiveness in humans. The same applies to many nutraceuticals and herbal products.
2. Studies on CBD as a single substance may say little about full-spectrum CBD products. Preclinical findings point to synergistic effects with other cannabinoids and terpenes (the entourage effect), but human data on this are scarce.
Important note: The following information is based on published studies and is not a substitute for medical advice. CBD is not an approved medicine for sleep disorders (Swissmedic/FOPH). Effectiveness has not been proven, and individual results may vary. If needed, talk to a doctor.
Research on CBD and sleep has grown in recent years but remains limited overall. Among the most relevant work are a meta-analysis of randomised clinical trials by Kuhathasan et al. (2019), which points to possible mild improvements in sleep quality in anxiety-related disorders (6), and the randomised clinical trial by Ried et al. (2023) in the Journal of Sleep Research (24 insomnia patients, THC:CBD combination), which reported improvements in subjective sleep quality (+80%, small sample) (7).
In addition, the scoping review by Amaral et al. (2023) summarises preclinical and clinical data and discusses possible sedative effects of CBD at higher doses (8). A frequently cited retrospective study by Shannon et al. (2019) looked at 72 adults with anxiety disorders and sleep problems (9). After one month of taking CBD (25–175 mg daily), over 66 percent subjectively reported changed sleep scores, although the effects fluctuated.
A randomised, placebo-controlled study by Skelley et al. (2020) examined the effects of four weeks of CBD supplementation on various health parameters (10). Some sleep markers improved subjectively, but the effects were not always statistically significant compared with placebo.
A systematic review by Suraev et al. (2020) analysed 34 studies on cannabis, cannabinoids and sleep (11). The authors conclude that the evidence for CBD in sleep disorders is insufficient and that methodologically stronger studies are needed.
CBD and falling asleep: which doses have been studied?
There is currently no clear answer on what dose of CBD makes sense for sleep problems. The doses used in studies vary widely: from 25 mg to 300 mg or more per day.
Interestingly, some studies point to a biphasic effect: lower doses seem more likely to promote wakefulness, while higher doses may have a sedative effect. An older study by Nicholson et al. (2004) observed an alerting effect with 15 mg of CBD, while other studies using higher doses described sedative effects (12).
In Switzerland, the Federal Office of Public Health (FOPH) has classified CBD products with a THC content below one percent as food, but it makes no dosage recommendations for therapeutic use. If you are considering CBD for sleep problems, discuss it with a healthcare professional and start with low doses.
CBD and sleep duration: which sleep parameters have been studied?
The available studies give mixed results on which sleep parameters are affected by CBD. Some show improvements in subjectively perceived sleep quality, while effects on objectively measurable parameters such as total sleep time are less clear.
A small study by Carlini and Cunha (1981) observed that higher CBD doses (160 mg) increased total sleep time in insomnia patients (13).
Some research is examining whether CBD plays a role mainly in stress-related sleep problems, since it may act on anxiety and tension. For primary sleep disorders without a psychological component, the evidence is weaker.
What are the differences between CBD, THC and conventional sleeping pills?
When assessing CBD, it is important to distinguish it from THC and conventional sleep medication. THC, the main psychoactive compound in the cannabis plant, shows clearer sedative effects than CBD in studies, but it comes with psychoactive effects up to strong temporary changes in consciousness and a higher potential for dependence.
Conventional benzodiazepines and Z-drugs (such as zolpidem) are effective for sleep disorders but carry major risks such as tolerance, dependence and disrupted sleep architecture. A review by Babson et al. (2017) in Current Psychiatry Reports discusses cannabinoids as a possible area of research but stresses that the data are still insufficient (14).
One possible difference from conventional sleeping pills is CBD's lower potential for dependence. In a 2018 report, the World Health Organization (WHO) stated that CBD shows no potential for abuse or dependence in humans (15).
How long has CBD been tested in recent sleep studies?
Most available studies on CBD and sleep are short-term, lasting from a few weeks to three months. Long-term studies of six months or more are largely missing.
The study by Shannon et al. (2019) mentioned above followed participants over three months. The authors found that the initial changes in sleep scores fluctuated over time, which raises questions about how lasting the effects are (9). Long-term studies are urgently needed to properly assess the long-term safety and longer-term effects of CBD in chronic sleep disorders.
What side effects were reported in recent CBD sleep studies?
An important part of any assessment is the side-effect profile. In most studies, CBD was relatively well tolerated, and the most commonly reported side effects were mild.
In the study by Shannon et al. (2019), some participants reported tiredness and diarrhoea, though only to a small extent. A systematic review by Chesney et al. (2020) in Cannabis and Cannabinoid Research analysed side effects from 25 studies and concluded that CBD was well tolerated overall. The most common side effects were tiredness, diarrhoea and changes in appetite (16).
Important: CBD can interact with various medications because it is broken down by the cytochrome P450 system in the liver, which also metabolises other drugs. If you take other medication, be sure to get medical advice before using CBD.
Are there studies on CBD and insomnia, nightmares or PTSD-related sleep problems?
A particularly interesting area of research concerns CBD in specific sleep disorders linked to mental health conditions. Several studies have looked at CBD in post-traumatic stress disorder (PTSD), which often comes with sleep problems and nightmares.
A case series by Elms et al. (2019) (17) in Journal of Alternative and Complementary Medicine reported improvements in PTSD symptoms, including sleep quality, in adults taking CBD. However, the sample was small and there was no control group.
Shannon and Opila-Lehman (2016) (18) published in Permanente Journal a case report on a child with PTSD whose sleep quality improved and anxiety symptoms decreased while taking CBD. Such single case reports are interesting but cannot be generalised.
For the specific diagnosis of primary insomnia without accompanying mental health conditions, high-quality studies are largely lacking. The European Medicines Agency (EMA) has so far not approved any CBD preparations for sleep disorders.
How quickly does CBD take effect according to studies?
The pharmacokinetics of CBD depend heavily on how it is taken. When taken orally (oils, capsules), peak plasma levels are typically reached after one to two hours. Because of the first-pass effect, the chemical conversion of the compound in the liver, oral bioavailability is only around 6 to 19 percent.
There are hardly any precise data on how quickly possible effects on sleep parameters appear. In clinical studies, CBD was usually taken for several days or weeks before effects were evaluated. Some user reports describe changes within a few days, but systematic studies on the time course are lacking.
With sublingual use of CBD oils, and even more so with inhalation, effects can theoretically set in faster than with capsules, because part of the compound enters the bloodstream directly through the mucous membranes of the mouth or through the lungs.
What do Swiss authorities and professional bodies say about CBD and sleep disorders?
In Switzerland, CBD products with a THC content below one percent are classified as food, not as medicines. The Federal Office of Public Health (FOPH) has made it clear that no therapeutic claims may be made for such products.
Swissmedic, the Swiss agency for the authorisation and supervision of medicines, has so far approved only a few CBD-containing medicines. There is no official approval for sleep disorders.
Professional bodies such as the Swiss Society for Sleep Research, Sleep Medicine and Chronobiology (SGSSC) have not yet taken an official position on CBD for sleep disorders. Current guidelines for treating insomnia mainly recommend behavioural therapy approaches and, where appropriate, short-term sleep medication.
Can CBD replace conventional sleeping pills or only complement them?
Based on current research, CBD cannot be recommended as a replacement for established sleep therapies. The evidence is still too limited, and effect sizes in many studies are moderate.
For mild sleep problems or stress-related difficulty falling asleep, CBD is discussed in research as a possible complementary option, for example when conventional treatments are not tolerated or not wanted. This should always be discussed with a healthcare professional, however.
For chronic insomnia, cognitive behavioural therapy for insomnia (CBT-I) is considered the gold standard and should be the first-line treatment. A meta-analysis by Trauer et al. (2015) (19) in the Annals of Internal Medicine showed that this non-drug therapy is highly effective.
Which form of CBD (oil, capsules etc.) has been studied most according to current data?
Most clinical studies on CBD and sleep used oral forms, either oil or capsules. Direct comparisons between different forms are largely missing.
CBD oils taken sublingually theoretically offer flexible dosing and possibly faster absorption. Capsules, on the other hand, allow more precise dosing and are tasteless.
For inhaled CBD (using a vaporiser) there are hardly any data in the context of sleep disorders. This form leads to higher bioavailability and a faster onset.
How do you recognise high-quality CBD products?
The quality of CBD products on the market varies widely. These are the features to look for:
Lab certificates should confirm the exact CBD content and the absence of contaminants such as heavy metals, pesticides and solvent residues. Reputable manufacturers make these certificates of analysis publicly available.
In Switzerland, the THC content must be below one percent and clearly declared. Products should come from controlled cultivation and ideally be manufactured to GMP (Good Manufacturing Practice) standards.
Full-spectrum CBD oils contain other cannabinoids and terpenes besides CBD, which may act synergistically (the so-called entourage effect). CBD isolates, by contrast, contain only pure CBD. Science cannot yet say for certain which is preferable.
Conclusion: what's behind the hype around CBD and sleep disorders?
The scientific data on CBD and sleep disorders have grown considerably in recent years but are not yet sufficient for clear conclusions. Some studies point to possible effects, especially in sleep problems related to stress and anxiety, but large, methodologically sound, placebo-controlled long-term studies are lacking.
Since CBD cannot be patented, we are likely to see more of the often underestimated “real-world evidence” (RWE) for now. This means insights from data generated in everyday life, for example from patient records, apps, insurance data or registries. Unlike strict clinical trials with fixed groups, placebos and controls, they capture how a substance like CBD works for many people with different life circumstances, medications and complaints.
Research so far suggests that some people with mild to moderate sleep problems, especially those linked to anxiety or stress, report changes when taking CBD. However, the effects seem to vary greatly from person to person and are not comparable to the effectiveness of established sleep therapies.
If you are considering CBD for sleep problems, it is important to have realistic expectations and not to see it as a replacement for proven treatments. The foundation should be better sleep hygiene, cognitive behavioural therapy where appropriate and medical treatment if needed.
Legal disclaimer
This article is for information only and is not a substitute for medical advice. The content reflects the state of knowledge as of January 2026, and findings may change. Be sure to talk to a healthcare professional before using CBD. The author and heimatkult.ch accept no liability for the use of this information.
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