Last updated 9 August 2026 · Originally published 14 November 2022
Most articles about CBD and sleepiness are written for people who want to feel sleepy. This one is for everyone else — the people taking CBD in the morning for anxiety or pain, wondering whether they are about to spend the afternoon fighting to stay awake.
The short answer: at the doses most people actually take, probably not — although direct evidence at those doses is thin. At the doses used in medicine, quite possibly.
At a glance
- Drowsiness is one of the most commonly reported side effects of prescription CBD — but those doses are enormous compared with a retail product.
- In trials of purified CBD for epilepsy, sleepiness affected around a third of patients, against roughly one in ten on placebo.
- A small 2025 randomised trial found that low-dose THC–CBD oils taken during the day produced no more sleepiness than placebo.
- The effect is dose-dependent, which is why the two findings do not contradict each other.
- Some of what people describe as CBD making them “relaxed” may be reduced anxiety or pain rather than sedation.
- If you are drowsy on CBD, check what else is in the product — and what else you are taking.
What the prescription data shows
The clearest evidence comes from trials of purified prescription CBD in severe epilepsy. Pooled data from those trials show somnolence and sedation among the most frequently reported adverse effects, occurring in around 32% of patients compared with 11% on placebo.[2]
Two details matter more than the headline figure.
It rose with dose. Sedation was more common at 20 mg/kg daily than at 10 mg/kg. For an average adult that is roughly 700 to 1,400 mg a day — between thirty and a hundred times a typical retail serving.
It rose sharply alongside other drugs. Among patients receiving prescription CBD, somnolence or sedation occurred in 46% of those also taking clobazam, compared with 16% of those not taking it. CBD can increase exposure to clobazam’s active metabolite, and clobazam is itself sedating.
These effects were generally most common early in treatment and sometimes diminished with continued use.
So the honest reading is not “CBD makes you sleepy.” It is that high-dose CBD makes a substantial minority of people sleepy, particularly alongside other sedating medication.
What happens at ordinary doses
A 2025 randomised, placebo-controlled trial set out to answer exactly the question in this article’s title: does taking cannabinoid oil during the day make you drowsy?[1]
Twenty healthy adults attended five sessions a week apart, receiving a different treatment each time: two balanced THC:CBD oils (2 mg/2 mg and 5 mg/5 mg), two CBD-dominant oils (2 mg THC/32 mg CBD and 5 mg THC/80 mg CBD), and a placebo — with neither participants nor researchers knowing which was which. Sleepiness was measured at 40, 135 and 265 minutes afterwards using a validated scale.
Everyone got sleepier as the day wore on. But there was no difference between the active treatments and placebo at any point. The researchers attributed the drift to the testing environment — long sessions, questionnaires, lunch — rather than the oil.
Nor did the daytime doses disturb sleep that night: total sleep time, time taken to fall asleep and number of awakenings were all unchanged.
The caveats are real. Twenty people is small, they were healthy and unaccustomed to cannabis, and the doses were low — the authors note that these may simply have been too low to produce any effect either way. But it is the most direct test available, and it found nothing.
Why the two findings fit together
CBD’s adverse effects can be dose-dependent, and sedation appears to be no exception. Presenting side-effect data from 1,400 mg-a-day pharmaceutical use as though it applied to a 15 mg gummy is a common and misleading conflation — it is how CBD marketing ends up simultaneously promising alertness and better sleep.
There is also a second explanation for reported drowsiness that has nothing to do with sedation.
CBD has been studied for anxiety more than for many of its other common uses, although the clinical evidence remains limited and inconsistent. If CBD does ease someone’s anxiety, the resulting calm may be difficult to distinguish from sleepiness — particularly if the anxiety was keeping them keyed up in the first place. The same may apply to pain: people who hurt less often rest better.
Our guide to whether CBD actually helps you sleep looks at that indirect route in more detail.
If CBD is making you drowsy
Check what else is in the product. Many CBD products also contain melatonin, CBN or THC. Melatonin and THC may contribute directly to drowsiness; CBN is widely marketed for sleep, although evidence that it is independently sedating remains weak. A “CBD” gummy with 3 mg of melatonin in it is partly a melatonin gummy.
Check what else you are taking. The clearest signal in the clinical data is CBD combined with other sedating substances — anti-epileptics, benzodiazepines, sleep medication, antihistamines, alcohol. That combination is worth a conversation with a pharmacist rather than an experiment.
Consider the dose and the timing. Oral CBD peaks slowly, and effects can persist for hours. Moving a dose to the evening is a simpler fix than abandoning it.
Do not drive or operate machinery if you feel impaired — and note that full-spectrum products contain THC, which carries its own driving implications regardless of how alert you feel.
Watch for the opposite problem too. Insomnia is also listed among the reported side effects of prescription CBD. Individual responses vary more than the marketing suggests.
None of this is medical advice. If drowsiness is affecting your daily life, or you take prescription medication, speak to a doctor or pharmacist.
For the wider picture, see our guide to CBD and what the research actually shows, or browse Sleep.
References
- Narayan AJ, Manning B, Aitken B, Downey LA, Hayley AC. Same-day sedative and night-time sleep effects following combined cannabinoid formulations: a randomised-controlled trial. Clinical Drug Investigation. 2025;45(7):417–429. doi:10.1007/s40261-025-01455-6
- Epidiolex (cannabidiol) oral solution: US prescribing information. Pooled somnolence and sedation data from controlled trials in Lennox–Gastaut syndrome and Dravet syndrome. FDA label
- Devinsky O, Cross JH, Laux L, et al. Trial of cannabidiol for drug-resistant seizures in the Dravet syndrome. New England Journal of Medicine. 2017;376(21):2011–2020. doi:10.1056/NEJMoa1611618
- Narayan AJ, Downey LA, Rose S, Di Natale L, Hayley AC. Cannabidiol for moderate-severe insomnia: a randomized controlled pilot trial of 150 mg of nightly dosing. Journal of Clinical Sleep Medicine. 2024;20(5):753–763. doi:10.5664/jcsm.10998
About this article
Rewritten in August 2026 to focus on daytime drowsiness as a side effect rather than as a desired outcome. This update adds the 2025 randomised trial of daytime cannabinoid dosing, sets out the dose-dependence of sedation, and separates CBD’s direct effects from the indirect calm that may follow reduced anxiety or pain. With earlier reporting by Robert Hammell.
