Sleep, Energy & Cognition
Does CBD Help With Sleep?
The short answer
The trial evidence is real but modest, mixed, and much smaller than the wellness-industry claims around it. A 2-week, placebo-controlled trial of 150mg nightly CBD alone found no significant difference from placebo on insomnia severity, sleep-onset latency, or sleep efficiency — though it did find better sleep efficiency and well-being at the 2-week mark. A larger, 125-person trial of an oral CBD-terpene formulation found a small but statistically significant increase in deep and REM sleep, averaging just over 1% of the night. A THC-CBD combination oil helped 60% of participants in one small trial no longer qualify as clinical insomniacs — but a similarly dosed THC-CBD combination in a Parkinson's disease trial showed sleep, cognition, and daily-functioning scores that favored placebo, not the cannabinoid. And a larger 178-person anxiety trial using CBD alone found sleep quality improved as a secondary outcome alongside its primary anxiety benefit. The direction is inconsistent, the trials are small, and 'CBD' in these studies is rarely one consistent product or dose.
Quick answers
- What is it?
- Whether CBD (cannabidiol) actually helps people sleep better, according to controlled human trials.
- Why are people interested in it?
- CBD is widely sold as a sleep aid, and people want to know whether controlled trials actually back that claim up.
- What has actually been studied?
- Randomized, placebo-controlled trials ranging from 15 to 178 participants, including a dedicated CBD-alone insomnia pilot trial, a larger CBD-terpene formulation trial, THC-CBD combination trials in insomnia and Parkinson's disease patients, and an anxiety trial that measured sleep as a secondary outcome.
- How strong is the evidence?
- Multiple randomized controlled trials, but results are small, mixed, and inconsistent — some trials show no significant effect on core sleep measures, others show modest benefits, and one shows results favoring placebo.
- What don't we know yet?
- Whether CBD alone at a specific dose reliably improves core sleep measures, why THC-CBD combinations produced opposite results in different populations, whether the terpenes or CBD (or both) drive any modest effect, whether CBD acts directly on sleep or through reducing anxiety, and long-term effects beyond 15 weeks.
- Where can I read the original research?
- Sources at the bottom of this page: 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; Wang M, Faust M, Abbott S, et al. Effects of a cannabidiol/terpene formulation on sleep in individuals with insomnia.
The short answer: The clinical trial evidence for CBD and sleep is real, but it's smaller, more inconsistent, and more product-dependent than the marketing around CBD sleep aids implies. A 2-week, placebo-controlled trial of 150mg of CBD alone, taken nightly, found no significant difference from placebo on insomnia severity, sleep-onset latency, or nighttime waking — though it did find an improvement in objective sleep efficiency and general well-being by the two-week mark. A larger, 125-person trial of an oral CBD-terpene formulation (no THC) found a small but statistically significant increase in deep and REM sleep combined, averaging just over one percent of the night. A THC-CBD combination oil helped 60% of participants in one small trial no longer qualify as clinical insomniacs — but a similarly dosed THC-CBD combination tested in Parkinson's disease patients showed sleep, cognition, and daily-functioning scores that favored the placebo group, not the cannabinoid. And in a larger 178-person trial built around anxiety rather than sleep, CBD alone significantly improved sleep-quality scores as a secondary outcome. Put together: there's a real signal in some trials, no signal in others, and very little consistency in what "CBD" actually means from one study to the next.
What the research shows
A dedicated CBD-alone insomnia trial found mostly null results
The most direct test of CBD by itself for sleep comes from a 2024 randomized, placebo-controlled pilot trial in the Journal of Clinical Sleep Medicine. Fifteen people with primary insomnia received 150mg of CBD nightly, sublingually, 60 minutes before bed, and fifteen received placebo, over a 2-week double-blind phase following a placebo run-in week. Sleep was tracked with wrist actigraphy and daily diaries. On the trial's core measures — insomnia severity, self-reported sleep-onset latency, sleep efficiency, and wake after sleep onset — CBD did not differ from placebo at any point (all p>.05). It wasn't entirely a null result: the CBD group reported significantly greater well-being throughout and showed superior objectively measured sleep efficiency at the 2-week endpoint. The authors called it similar to placebo on most sleep outcomes, with some benefit to well-being, and urged trials of other doses and durations.
A larger trial found a small, statistically real effect
A 2025 double-blind, placebo-controlled crossover trial in the same journal tested a different formulation — 300mg of CBD combined with eight terpenes (linalool, myrcene, phytol, limonene, and others), with no THC — in 125 people with insomnia, over 4 weeks. The primary outcome was the percentage of the night spent in slow-wave and REM sleep combined, tracked with a wrist-worn monitor. The formulation produced a statistically significant, if modest, increase versus placebo: 1.3 percentage points more of the night in these restorative stages (95% CI, 0.1-2.5%; p=.03), more pronounced in people who started with low baseline slow-wave-plus-REM sleep and in day sleepers, with some individuals gaining up to 48 minutes per night. Total sleep time, resting heart rate, and heart rate variability were unchanged, and no adverse events were reported. This is the largest CBD-alone sleep trial reviewed here, and it found a real, if small, effect on sleep architecture rather than total sleep time.
Adding THC changes the story — in different directions in different trials
CBD is frequently sold and studied alongside THC rather than in isolation, and the evidence there pulls in opposite directions depending on the population. A 2022 randomized, double-blind, placebo-controlled crossover trial in the Journal of Sleep Research tested a THC:CBD oil (10mg/mL THC, 15mg/mL CBD) in 29 adults with self-reported clinical insomnia over a 6-week trial with washout between phases. The results were strongly positive by several measures: 60% of participants no longer met criteria for clinical insomnia by the end of the 2-week active treatment period, midnight melatonin rose 30% in the active group versus a 20% decline with placebo (p=.035), light sleep increased by 21 minutes per night (p=.041), and self-rated sleep quality improved by up to 80% (p=.003). The authors flagged a limitation worth taking seriously: effects were more pronounced in the crossover's second phase, consistent with a period effect and probable loss of blinding, since THC's psychoactive effects make it hard to keep participants unaware of which treatment they're on.
A different picture emerged from a 2024 randomized trial in Movement Disorders, testing a comparable CBD/THC combination (average final dose 191.8mg CBD plus 6.4mg THC daily) in 61 people with Parkinson's disease, 31 assigned to the cannabinoid and 30 to placebo, over roughly 2 weeks. Motor symptoms improved similarly in both groups, reflecting a strong placebo response. But sleep, cognition, and activities of daily living showed a treatment effect favoring placebo — the people taking CBD/THC did worse on these measures than the people taking placebo — alongside more adverse events in the cannabinoid group. The authors were direct: the trial was brief and the placebo response strong, but they found no benefit and possibly worsened cognition and sleep with active treatment.
A larger CBD-alone trial found a sleep benefit as a side finding
Not every relevant trial was designed around sleep. A 2024 phase 3, multicenter, double-blind trial in the Asian Journal of Psychiatry tested a nanodispersible CBD oral solution against placebo in 178 adults with mild-to-moderate anxiety (89 per group) over 15 weeks in India. Its primary outcomes were anxiety scales, both showing large, highly significant improvements with CBD (GAD-7 difference of −7.02 points, p<.0001; HAM-A difference of −11.9 points, p<.0001). Sleep quality, measured with the Pittsburgh Sleep Quality Index as a secondary outcome, was reported as significantly improved with CBD versus placebo too, alongside depression scores. It's a larger, longer trial than the dedicated insomnia studies above, but sleep wasn't its purpose, and the improvement may reflect reduced anxiety generally rather than a specific effect on sleep physiology.
What we don't know yet
Whether CBD alone, at a specific dose, reliably improves core sleep measures. The one trial testing CBD in isolation against the standard insomnia outcomes (severity, onset latency, efficiency, waking) found no significant difference from placebo on those specific measures.
Why THC-CBD combinations produced opposite sleep results in two different trials. One combination trial in people with insomnia found strong, if likely unblinded, benefits; a similar combination in people with Parkinson's disease found sleep scores favoring placebo — and no retrieved study explains whether the difference is the population, the dose ratio, or something else.
Whether the small effect seen with CBD-terpene formulations is driven by CBD, the terpenes, or their combination. The 125-person trial tested CBD plus eight terpenes as a single product; no arm isolated CBD alone or terpenes alone to see which ingredient, if either, drove the modest sleep-architecture change.
Whether CBD's effect on sleep is direct or secondary to its effect on anxiety. In the largest CBD-alone trial reviewed here, sleep quality improved only as a secondary outcome in an anxiety trial, leaving open whether CBD acts on sleep directly or simply through reducing anxiety that was disrupting sleep in the first place.
Long-term effects and optimal duration. Every trial here ran 2 to 15 weeks; none tested outcomes over months or years of regular use, and none established whether initial small effects (or lack of effects) change with longer treatment.
Sources
- 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
- Wang M, Faust M, Abbott S, Patel V, Chang E, Clark JI, Stella N, Muchowski PJ. Effects of a cannabidiol/terpene formulation on sleep in individuals with insomnia: a double-blind, placebo-controlled, randomized, crossover study. Journal of Clinical Sleep Medicine, 2025;21(1):69-80. DOI
- Ried K, Tamanna T, Matthews S, Sali A. Medicinal cannabis improves sleep in adults with insomnia: a randomised double-blind placebo-controlled crossover study. Journal of Sleep Research, 2022;32(3):e13793. DOI
- Liu Y, Bainbridge J, Sillau S, et al. Short-Term Cannabidiol with Δ-9-Tetrahydrocannabinol in Parkinson's Disease: A Randomized Trial. Movement Disorders, 2024;39(5):863-875. DOI
- Gundugurti PR, Banda N, Yadlapalli SSR, Narala A, Thatikonda R, Kocherlakota C, Kothapalli KS. Evaluation of the efficacy, safety, and pharmacokinetics of nanodispersible cannabidiol oral solution (150 mg/mL) versus placebo in mild to moderate anxiety subjects: A double blind multicenter randomized clinical trial. Asian Journal of Psychiatry, 2024;97:104073. DOI
Article records maintained via PubMed. Peptide Proof reports what studies found. It does not provide medical advice, dosing guidance, or treatment recommendations.
Topic: Sleep & Recovery
Sources
- Cannabidiol for moderate-severe insomnia: a randomized controlled pilot trial of 150 mg of nightly dosing
- Journal of Clinical Sleep Medicine, 2024 · n=30 · DOI
- Effects of a cannabidiol/terpene formulation on sleep in individuals with insomnia: a double-blind, placebo-controlled, randomized, crossover study
- Journal of Clinical Sleep Medicine, 2025 · n=125 · DOI
- Medicinal cannabis improves sleep in adults with insomnia: a randomised double-blind placebo-controlled crossover study
- Journal of Sleep Research, 2022 · n=29 · DOI
- Short-Term Cannabidiol with Δ-9-Tetrahydrocannabinol in Parkinson's Disease: A Randomized Trial
- Movement Disorders, 2024 · n=61 · DOI
- Evaluation of the efficacy, safety, and pharmacokinetics of nanodispersible cannabidiol oral solution (150 mg/mL) versus placebo in mild to moderate anxiety subjects
- Asian Journal of Psychiatry, 2024 · n=178 · DOI
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