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Does CBD help with anxiety, sleep or pain? What the evidence shows

Small trials suggest CBD can take the edge off anxiety, but the largest review found no clear benefit, and CBD alone has not reliably improved sleep.

Published October 2026

Short answer

The evidence is early and mixed: small studies hint that CBD can calm anxiety, but a 54-trial review found no clear benefit, and CBD on its own has not reliably helped sleep. Evidence grade C (Limited). Mixed results from small, partly industry-run trials and meta-analyses that disagree, downgraded for inconsistency, small samples and high risk of bias in much of the evidence.

Key takeaways

  • An analysis of 8 trials in 316 people found CBD lowered anxiety scores, but the authors warn the small sample makes the result uncertain [1].
  • A 178-person trial reported anxiety scores falling about 7 points more with CBD than placebo, while a 54-trial review of 2,477 people found no significant anxiety effect [2] [3].
  • For sleep, pooled trials found benefits mainly from non-CBD cannabinoids; CBD-only products showed no significant effect [4].
  • A 125-person trial found 300 mg of CBD plus terpenes slightly increased deep and REM sleep; the study was funded by the product's maker [5].
  • CBD is usually well tolerated, but high doses can raise liver enzymes and it can interact with medicines such as warfarin and valproate [6] [7].

The short version

Some small trials and one 178-person study suggest CBD (cannabidiol) can take the edge off anxiety, but a 2026 review of 54 cannabinoid trials found no clear benefit [2] [3]. For sleep, CBD on its own has not reliably helped; the pooled trials that show sleep benefits mostly tested cannabinoids other than CBD [4]. CBD is generally well tolerated at typical doses, but it can interact with prescription medicines [8] [7].

What the studies show

Anxiety. A 2024 meta-analysis pooled 8 trials in 316 people and found CBD lowered anxiety scores, with a large average effect (effect size -0.92, 95% CI -1.80 to -0.04); the authors caution that the small sample makes the result uncertain [1]. A 178-person phase 3 trial reported that anxiety scores (GAD-7) fell 7.02 points more with a nano-dispersed CBD solution than with placebo over 15 weeks (95% CI -7.52 to -6.52) [2]. That trial was run by the company developing the product, and its employees were among the authors [2]. On the other side, a 2026 review of 54 trials in 2,477 people found no significant effect of cannabinoids on anxiety outcomes and rated most evidence low certainty [3], and a 2022 trial in 80 patients with social anxiety disorder or panic disorder found that adding 300 mg of CBD to exposure therapy did not improve outcomes [9].

Sleep. A 2025 meta-analysis of 6 trials (1,077 people) found cannabinoids improved self-reported sleep quality overall (SMD 0.53, 95% CI 0.03 to 1.02), but the benefit came from cannabinoids other than CBD (SMD 0.82); CBD-only products showed no significant effect (SMD 0.13, 95% CI -0.38 to 0.65) [4]. The 2026 review also found cannabinoids increased sleep time in people with insomnia (about half a standard deviation, measured by both trackers and diaries) [3]. In a 125-person trial, 300 mg of CBD plus terpenes increased deep and REM sleep by about 1.3% of the night (95% CI 0.1 to 2.5), with no change in total sleep time; the product's maker funded the study [5]. A 30-person pilot trial of 150 mg CBD found no difference in insomnia severity or most sleep measures, though sleep efficiency on a wrist tracker was better after two weeks [10].

Seizures. Prescription CBD has the strongest evidence of any CBD use: taken as an add-on, it reduces seizures in severe treatment-resistant childhood epilepsies [11]. An umbrella review of meta-analyses rated it high certainty for at least halving seizure frequency (OR 0.59, 95% CI 0.38 to 0.92), and a large meta-analysis of 152 randomised trials across conditions found CBD reduced seizure measures with high-grade evidence [11] [12]. The trials used higher doses than typical supplements, about 15 mg/kg per day on average [13].

Pain. For chronic pain, the pooled benefits come from medicines containing THC (such as nabiximols, a THC-CBD spray; SMD -0.25, 95% CI -0.37 to -0.14), while a review of CBD-only trials, mostly at low doses, found no clear effect on chronic pain [12] [13].

The nuances

The trials are mostly small and short, and they disagree: one meta-analysis finds an anxiety benefit while the largest review finds none [1] [3]. Expectations can shape results: in two studies where people were given CBD-free oil but told it contained CBD, believing in CBD was linked to changes in stress and anxiety responses [PMID 33813611] [PMID 38214314]. Doses tested ranged from 150 mg to 800 mg a day in short trials, and about 15 mg/kg a day in epilepsy [10] [14] [13]. One review of 58 CBD trials found most were very small (72% had fewer than 40 participants) and results varied widely between conditions [15].

Side effects are usually mild: the most common are diarrhoea, sleepiness, sedation and cold-like symptoms [8]. Pooled across the 54 trials, cannabinoids raised the odds of any side effect (about one extra person in seven) but not of serious side effects [3]. CBD raised the odds of liver enzyme rises about six-fold in trials, mainly at high doses (1,000 mg a day or more, or 20 mg/kg and above) and in people taking antiepileptic drugs; no cases were seen in adults taking under 300 mg a day, and none were severe [6]. CBD is processed by the same liver enzymes as many medicines, and case reports link it to changed blood levels of warfarin, valproate, tacrolimus and sirolimus, with problems including bleeding and sedation [7]; warfarin is the blood thinner with reported interactions, mostly at very high doses [16]. Health organisations advise avoiding cannabis and CBD products during pregnancy and breastfeeding, because data on CBD alone are very limited [17].

What this means for you

A few small trials and one larger industry-funded trial suggest CBD can help some people feel calmer, but the overall evidence for anxiety remains mixed and early [1] [2] [3]. The sleep benefits found in trials came mostly from cannabinoids other than CBD, and cannabis itself carries risks such as car crashes and mental health harms [4] [11]. Many over-the-counter cannabinoid products, including CBD oils, are unregulated [7]. The clearest use of CBD is as a prescription add-on for severe childhood epilepsy [11] [13]. If you take prescription medicines or have liver problems, talk to a doctor or pharmacist before using CBD [6] [7].

Go deeper

  • CBD — Small trials suggest CBD can take the edge off anxiety, but a 54-trial review found no clear benefit.

References

  1. Therapeutic potential of cannabidiol (CBD) in anxiety disorders: A systematic review and meta-analysis.. Psychiatry Res, 2024.
  2. 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 J Psychiatr, 2024.
  3. The efficacy and safety of cannabinoids for the treatment of mental disorders and substance use disorders: a systematic review and meta-analysis.. Lancet Psychiatry, 2026.
  4. Effectiveness of cannabinoids on subjective sleep quality in people with and without insomnia or poor sleep: A systematic review and meta-analysis of randomised studies.. Sleep Med Rev, 2025.
  5. Effects of a cannabidiol/terpene formulation on sleep in individuals with insomnia: a double-blind, placebo-controlled, randomized, crossover study.. J Clin Sleep Med, 2025.
  6. Cannabidiol-associated hepatotoxicity: A systematic review and meta-analysis.. J Intern Med, 2023.
  7. Systematic review of drug-drug interactions of delta-9-tetrahydrocannabinol, cannabidiol, and Cannabis.. Front Pharmacol, 2024.
  8. Update on Cannabidiol Clinical Toxicity and Adverse Effects: A Systematic Review.. Curr Neuropharmacol, 2023.
  9. Cannabidiol enhancement of exposure therapy in treatment refractory patients with social anxiety disorder and panic disorder with agoraphobia: A randomised controlled trial.. Eur Neuropsychopharmacol, 2022.
  10. Cannabidiol for moderate-severe insomnia: a randomized controlled pilot trial of 150 mg of nightly dosing.. J Clin Sleep Med, 2024.
  11. Balancing risks and benefits of cannabis use: umbrella review of meta-analyses of randomised controlled trials and observational studies.. BMJ, 2023.
  12. Medical cannabinoids: a pharmacology-based systematic review and meta-analysis for all relevant medical indications.. BMC Med, 2022.
  13. A systematic review of cannabidiol dosing in clinical populations.. Br J Clin Pharmacol, 2019.
  14. Cannabidiol for the Reduction of Cue-Induced Craving and Anxiety in Drug-Abstinent Individuals With Heroin Use Disorder: A Double-Blind Randomized Placebo-Controlled Trial.. Am J Psychiatry, 2019.
  15. The Effectiveness and Safety of Cannabidiol in Non-seizure-related Indications: A Systematic Review of Published Randomized Clinical Trials.. Pharmaceut Med, 2022.
  16. Anticoagulant drug-drug interactions with cannabinoids: A systematic review.. Pharmacotherapy, 2023.
  17. Medical Cannabis During Pregnancy and Breastfeeding: Is the Concern Fully Evidence-Based?. Biomedicines, 2026.