Safety guide
Sedation and somnolence: what to know
A source-linked guide to Sedation and somnolence, the situations researchers have examined, and the details that can change risk.
The short answer
Why does Sedation and somnolence matter?
Sedation and somnolence is an important cannabinoid safety topic. Studies and reviews examine CBD. This page brings together 10 human-study sources and 2 research reviews. It includes 5 specific study findings from 4 sources. The source set includes human research as well as earlier-stage studies. The compound, dose, route, other medications, and individual health context all matter. 1
Key takeaways
What to know first
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Research on Sedation and somnolence covers CBD; those areas should not be combined into one claim. 1
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The source set includes human research as well as earlier-stage studies. 2
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Dose, formulation, route, study population, and outcome can change how closely a study applies to a real-world question. 3
Research areas
What researchers studied about Sedation and somnolence
These are the main questions represented in the current literature. Each link opens a source used to build the overview.
Human research included
CBD
Research involving CBD contributes to the larger Sedation and somnolence question. Risk can change with dose, route, formulation, other substances, medications, and the person being studied. 3
Results extracted so far
What did the studies report?
These summaries appear only when the recorded study outcome is specific enough to reproduce from the linked source. If a source has no result summary here, the result has not been extracted yet; that does not mean the study found no effect.
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In a systematic review and meta-analysis of medical cannabis for adult insomnia involving adults with insomnia across included studies, researchers reported an increase in sleep improvement attributed to 50-to-300-mg CBD doses in an insomnia review following CBD 50 to 300 mg in the favorable review conclusion by the oral or sublingual across included studies route over varied across included studies. The recorded comparator was varied across included studies. 1
Recorded result: The abstract concluded that CBD doses of 50 to 300 mg were safe and effective for improving sleep; it did not report a CBD-specific pooled effect estimate.
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In a randomized double-blind placebo-controlled clinical trial involving 224 patients aged 1-65 with tuberous sclerosis complex and medication-resistant epilepsy, researchers reported an increase in somnolence frequency following 25 mg/kg/day by the oral route over 16 weeks. The recorded comparator was matched placebo. 2
Recorded result: Somnolence occurred in 13% with 25 mg/kg/day and 9% with placebo.
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In a randomized double-blind placebo-controlled clinical trial involving 224 patients aged 1-65 with tuberous sclerosis complex and medication-resistant epilepsy, researchers reported an increase in somnolence frequency following 50 mg/kg/day by the oral route over 16 weeks. The recorded comparator was matched placebo. 2
Recorded result: Somnolence occurred in 26% with 50 mg/kg/day and 9% with placebo.
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In a randomized placebo-controlled crossover trial involving 64 patients with primary hypertension, researchers reported a decrease in excessive daytime sleepiness in primary hypertension following 225 to 450 mg by the not stated in the PubMed abstract route over 5 weeks per condition. The recorded comparator was placebo. 3
Recorded result: ESS score improved during CBD but not placebo (F=6.738; P=.011).
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In a retrospective multicenter chart review involving 126 patients with LGS or DS receiving CBD with clobazam, researchers reported an increase in sedation frequency with concomitant clobazam following median target CBD dose 11.1 mg/kg/day by the oral route over 12 months. The recorded comparator was none. 4
Recorded result: Sedation occurred in 30 patients (23.8%); diarrhea occurred in 13 (10.3%).
How strong is the research?
Not every study answers the same question
This page separates research in people, research reviews, and earlier-stage biology before interpreting the larger question.
Human studies
Research involving people is closest to everyday health questions. The product, dose, population, and outcome still determine what each study can show.
Reviews and evidence summaries
Reviews can compare several studies at once. Their conclusion is only as strong and as relevant as the studies they include.
Lab, animal, and mechanism research
Early-stage research can explain biological interest. It cannot, by itself, show that the same effect happens in people.
Another 1 of 13 research source could not be placed cleanly into those three groups from the recorded study details.
What these studies actually looked at
The research on Sedation and somnolence is not one kind of study. This source set includes 6 clinical studies in people, 3 cell or laboratory studies, 1 narrative or expert review, and 1 retrospective multicenter chart review. 3
The recorded populations or models include people or patients (10 sources), adults with insomnia across included studies (1 source), and pediatric, adolescent, or developmental context (1 source). A result from one group or model should not be assumed to apply to another. 4
The most common recorded outcome focus is safety, tolerability, sedation, adverse-event, impairment, or formulation-specific concerns (9 sources), epworth Sleepiness Scale (1 source), and participants with somnolence (1 source). Closely related outcome names can still describe different measurements. 5
Some source records specify doses including 225 to 450 mg (1 source), 25 mg or kg or day (1 source), and 50 mg or kg or day (1 source). These are descriptions of what researchers tested, not personal dosing instructions. 6
The Sedation and somnolence source set also contains findings or reviews that remain too limited, indirect, or mixed for a broad answer. That uncertainty is part of the result, not an empty space to fill with assumptions. 7
Examples from the literature
What did the studies actually look at?
Each example names the research question and the study details recorded for that source.
systematic review or meta-analysis
Medical cannabis for treatment of insomnia in adults: A systematic review and meta-analysis.
On this page, this source examines CBD and sleep improvement attributed to 50-to-300-mg CBD doses in an insomnia review. 1
- Study type
- systematic review or meta-analysis
- Population or model
- adults with insomnia across included studies
- Outcome focus
- sleep disturbance, daytime sleepiness, total sleep time, and validated insomnia scales
- Dose recorded
- cBD 50 to 300 mg in the favorable review conclusion
- Evidence stage
- systematic review
clinical study in people
Add-on Cannabidiol Treatment for Drug-Resistant Seizures in Tuberous Sclerosis Complex: A Placebo-Controlled Randomized Clinical Trial.
On this page, this source examines CBD and somnolence frequency. 2
- Study type
- clinical study in people
- Population or model
- people or patients
- Outcome focus
- participants with somnolence
- Dose recorded
- 25 mg or kg or day and 50 mg or kg or day
- Evidence stage
- human research
clinical study in people
Chronic Cannabidiol Administration Mitigates Excessive Daytime Sleepiness and Fatigue in Patients with Primary Hypertension: Insights from a Randomized Crossover Trial.
On this page, this source examines CBD and excessive daytime sleepiness in primary hypertension. 3
- Study type
- clinical study in people
- Population or model
- people or patients
- Outcome focus
- epworth Sleepiness Scale
- Dose recorded
- 225 to 450 mg
- Evidence stage
- human research
retrospective multicenter chart review
Real-world experience of cannabidiol in conjunction with clobazam for the treatment of seizures associated with Lennox-Gastaut syndrome and Dravet syndrome: Results from a retrospective multicentre chart review in Germany.
On this page, this source examines CBD and sedation frequency with concomitant clobazam. 4
- Study type
- retrospective multicenter chart review
- Population or model
- people or patients
- Outcome focus
- sedation frequency with concomitant clobazam
- Dose recorded
- median target CBD dose 11.1 mg or kg or day
- Evidence stage
- human research
clinical study in people
A double-blind, randomized, placebo-controlled study of the safety and effects of CBN with and without CBD on sleep quality
On this page, this source examines CBN and safety, tolerability, sedation, adverse-event, impairment, or formulation-specific concerns. 5
- Study type
- clinical study in people
- Population or model
- people or patients
- Outcome focus
- safety, tolerability, sedation, adverse-event, impairment, or formulation-specific concerns
- Evidence stage
- human research
Safety and limits
What should readers keep in mind?
This page is already focused on Sedation and somnolence. Risk can change with the cannabinoid, amount, route, frequency, formulation, other substances, medications, age, pregnancy, and underlying health conditions. 2
Research doses are descriptions of what a study tested. They are not personal dosing instructions. Questions involving medications, pregnancy, children, driving, liver health, heart health, or serious symptoms deserve professional medical guidance.
Common questions
Questions people ask
What is the main research question about Sedation and somnolence?
The literature on this page centers on CBD. The source set includes human research as well as earlier-stage studies. 7
How should I read the sources?
Start with the study design, then check the product, dose, route, population, outcome, and safety information. 8
Does this page give medical advice?
No. It explains published research and links to sources; it does not provide a diagnosis, treatment plan, or personal dosing advice. 9
Sources
Read the research
The numbered sources below support the main overview. Links open the PubMed record or DOI in a new tab.
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1
Medical cannabis for treatment of insomnia in adults: A systematic review and meta-analysis. systematic review or meta-analysis; systematic review PubMed 42207928 DOI 10.1097/jxx.0000000000001289
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2
Add-on Cannabidiol Treatment for Drug-Resistant Seizures in Tuberous Sclerosis Complex: A Placebo-Controlled Randomized Clinical Trial. clinical study in people; human research PubMed 33346789 DOI 10.1001/jamaneurol.2020.4607
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3
Chronic Cannabidiol Administration Mitigates Excessive Daytime Sleepiness and Fatigue in Patients with Primary Hypertension: Insights from a Randomized Crossover Trial. clinical study in people; human research PubMed 39187263 DOI 10.1089/can.2024.0028
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4
Real-world experience of cannabidiol in conjunction with clobazam for the treatment of seizures associated with Lennox-Gastaut syndrome and Dravet syndrome: Results from a retrospective multicentre chart review in Germany. retrospective multicenter chart review; human research PubMed 40073826 DOI 10.1016/j.yebeh.2025.110302
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5
A double-blind, randomized, placebo-controlled study of the safety and effects of CBN with and without CBD on sleep quality clinical study in people; human research PubMed 37796540 DOI 10.1037/pha0000682
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6
Cannabinol for acute treatment of insomnia disorder in a randomized placebo-controlled crossover trial clinical study in people; human research PubMed 41698831 DOI 10.1111/jsr.70284
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7
Effectiveness of a Cannabinoids Supplement on Sleep and Mood in Adults With Subthreshold Insomnia: A Randomized Double-Blind Placebo-Controlled Crossover Pilot Trial. clinical study in people; human research PubMed 39980821 DOI 10.1002/hsr2.70481
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8
The Safety and Comparative Effectiveness of Non-Psychoactive Cannabinoid Formulations for the Improvement of Sleep: A Double-Blinded, Randomized Controlled Trial. clinical study in people; human research PubMed 37162192 DOI 10.1080/27697061.2023.2203221
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9
[Cannabis: Effects in the Central Nervous System. Therapeutic, societal and legal consequences]. narrative or expert review; evidence still limited PubMed 27428345
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10
Comparison on the mechanism and potency of hepatotoxicity among hemp extract and its four major constituent cannabinoids. cell or laboratory study; mechanism-focused research PubMed 39004335 DOI 10.1016/j.tox.2024.153885
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11
Evaluation of the anti-inflammatory effects of selected cannabinoids and terpenes from Cannabis Sativa employing human primary leukocytes. cell or laboratory study; evidence still limited PubMed 36228902 DOI 10.1016/j.fct.2022.113458
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12
Examining the hepatotoxic potential of cannabidiol, cannabidiol-containing hemp extract, and cannabinol at consumer-relevant exposure concentrations in primary human hepatocytes. cell or laboratory study; evidence still limited PubMed 38924151 DOI 10.1002/jat.4646
See all 13 research sources
This complete source list is the deeper research layer for the page. Study type and evidence context are shown when they are available in the current record.
- A double-blind, randomized, placebo-controlled study of the safety and effects of CBN with and without CBD on sleep quality clinical study in people; human research / 1 linked research note PubMed 37796540
- Cannabinol for acute treatment of insomnia disorder in a randomized placebo-controlled crossover trial clinical study in people; human research / 1 linked research note PubMed 41698831
- Effectiveness of a Cannabinoids Supplement on Sleep and Mood in Adults With Subthreshold Insomnia: A Randomized Double-Blind Placebo-Controlled Crossover Pilot Trial. clinical study in people; human research / 1 linked research note PubMed 39980821
- Comparison on the mechanism and potency of hepatotoxicity among hemp extract and its four major constituent cannabinoids. cell or laboratory study; mechanism-focused research / 1 linked research note PubMed 39004335
- The Safety and Comparative Effectiveness of Non-Psychoactive Cannabinoid Formulations for the Improvement of Sleep: A Double-Blinded, Randomized Controlled Trial. clinical study in people; human research / 1 linked research note PubMed 37162192
- Examining the hepatotoxic potential of cannabidiol, cannabidiol-containing hemp extract, and cannabinol at consumer-relevant exposure concentrations in primary human hepatocytes. cell or laboratory study; evidence still limited / 1 linked research note PubMed 38924151
- [Cannabis: Effects in the Central Nervous System. Therapeutic, societal and legal consequences]. narrative or expert review; evidence still limited / 1 linked research note PubMed 27428345
- Review of NIOSH Cannabis-Related Health Hazard Evaluations and Research. evidence still limited / 1 linked research note PubMed 32053725
- Evaluation of the anti-inflammatory effects of selected cannabinoids and terpenes from Cannabis Sativa employing human primary leukocytes. cell or laboratory study; evidence still limited / 1 linked research note PubMed 36228902
- Add-on Cannabidiol Treatment for Drug-Resistant Seizures in Tuberous Sclerosis Complex: A Placebo-Controlled Randomized Clinical Trial. clinical study in people; human research / 2 linked research notes PubMed 33346789
- Chronic Cannabidiol Administration Mitigates Excessive Daytime Sleepiness and Fatigue in Patients with Primary Hypertension: Insights from a Randomized Crossover Trial. clinical study in people; human research / 1 linked research note PubMed 39187263
- Medical cannabis for treatment of insomnia in adults: A systematic review and meta-analysis. systematic review or meta-analysis; systematic review / 1 linked research note PubMed 42207928
- Real-world experience of cannabidiol in conjunction with clobazam for the treatment of seizures associated with Lennox-Gastaut syndrome and Dravet syndrome: Results from a retrospective multicentre chart review in Germany. retrospective multicenter chart review; human research / 1 linked research note PubMed 40073826