CBD for anxiety

CBD is not a proven treatment for anxiety. A handful of small studies found lower anxiety scores with doses of 300 to 600 mg in a public-speaking test or over a few weeks, but when placebo-controlled trials are pooled the effect is not statistically significant. No good trial has tested the low doses most people have in mind.

What the research shows

The studies that reported an effect

• Social anxiety, single dose. In a 2011 study, 24 people with social anxiety disorder who had never been treated took a single 600 mg dose of CBD or a placebo before a simulated public-speaking test. Those given CBD had less anxiety during the speech.¹
• Dose matters, in an odd way. A later public-speaking study found that 300 mg reduced anxiety compared with placebo, while both lower and higher doses did not. Researchers call this an inverted U-shaped dose response.²
• Four weeks in teenagers. A double-blind trial in Japan gave 37 teenagers aged 18 to 19 with social anxiety disorder either 300 mg of CBD (17 people) or placebo (20 people) each day for four weeks. Anxiety scores fell significantly more with CBD on both scales used.³

These were small studies. Two of the three tested a single dose in a laboratory setting, which is a long way from treating an anxiety disorder over months.

The Australian youth study

An Australian study gave CBD to 31 people aged 12 to 25 whose anxiety had not responded to standard treatment. The dose was increased up to 800 mg a day over 12 weeks. Self-rated anxiety scores fell by 42.6%, from 10.8 to 6.3.⁴

This study was open-label, which means there was no placebo group and everyone knew they were taking CBD. Anxiety responds strongly to expectation, and the authors themselves say a placebo effect cannot be ruled out.⁴ A placebo-controlled follow-up trial planned for 180 young people was still recruiting in November 2024. We found no published results as of November 2026.⁵

The pooled evidence

When reviewers gather all the trials, the picture is weaker.

• A 2024 systematic review found 15 randomised trials published from 2013 to 2023. In 9 of the 15 (60%), a single dose of CBD showed no benefit for anxiety.⁶
• A 2025 meta-analysis (a study that pools trials) covered 21 placebo-controlled trials, including trials in PTSD, obsessive-compulsive disorder and Tourette syndrome as well as anxiety disorders. Overall, the effect of pure or enriched CBD was not statistically significant, although a smaller subgroup of pure-CBD studies did reach significance. Only one of the 21 trials studied generalised anxiety disorder, the most common long-term form.⁷
• A 2026 review in The Lancet Psychiatry pooled 54 trials and 2,477 participants across all cannabinoids, including products with THC. It found no significant effect on anxiety outcomes and concluded that routine use of cannabinoids for mental disorders “is currently rarely justified”.⁸
• A 2025 double-blind trial of 150, 300 or 600 mg of CBD found no effect on fear and panic symptoms brought on by a carbon dioxide breathing test.⁹

See how we grade the evidence for why pooled, placebo-controlled results count for more than single small studies.

What doses were tested

The studies that reported an effect used 300 to 600 mg as a single dose, 300 mg a day for four weeks, or up to 800 mg a day.¹²³⁴

For comparison, the Australian limit for pharmacist-only (Schedule 3) CBD is 150 mg a day.¹⁰ A review by Australian researchers found that the benefits of oral CBD “became more clearly evident at doses ≥300 mg”.¹¹ No good trial has tested daily doses of 150 mg or less for an anxiety disorder, so the evidence above cannot be stretched to cover low-dose products. Our page on low-dose CBD goes into this.

What Australian medical bodies say

• RANZCP. The Royal Australian and New Zealand College of Psychiatrists updated its clinical memorandum in March 2024. It says there is insufficient evidence to support medicinal cannabis as a treatment for anxiety and other mental disorders, and raises concern about overprescribing.¹²
• RACGP. The Royal Australian College of General Practitioners calls the overall evidence base for medicinal cannabis “limited and inconclusive” and says it should only be considered after first-line, evidence-based treatments have been exhausted.¹³

The full picture is on our page about what Australian medical bodies say.

Risks to know about

• Side effects. In trials, the effects most often linked to CBD were diarrhoea and sleepiness.¹⁴ See CBD side effects.
• Liver enzymes at trial doses. In a study of healthy adults taking about 350 to 400 mg a day for four weeks, 5.6% had liver enzymes rise to more than three times the normal upper limit. None had symptoms, and levels returned to normal after stopping.¹⁵ That dose sits within the range used in anxiety studies. See CBD and the liver.
• Other medicines. CBD blocks several liver enzymes that break down other medicines, and it adds to the sedation from benzodiazepines, other sedatives and alcohol.¹⁶ In six participants in the Australian youth anxiety study who were also taking the antidepressants citalopram or escitalopram, citalopram blood levels rose after CBD was added. Whether that caused more side effects was not established.¹⁷ If you take any medicine for anxiety or depression, check CBD drug interactions and ask your pharmacist.
• THC is different. Some products prescribed for anxiety contain THC as well as CBD. In an Australian cancer trial, short-lived anxiety was reported more often with THC:CBD capsules (which contain THC) than with placebo, 4% against 1%.¹⁸ Check what a product contains. See CBD vs THC.

If you are considering it

• Start with your GP. Ask what the first-line treatments are for your type of anxiety and whether you have tried them properly. Our guide to talking to your GP about CBD may help.
• Bring a full list of your medicines and supplements.
• Questions worth asking about any treatment suggested: What evidence is there at the dose proposed? Does the product contain any THC? What are the risks and interactions with my other medicines? How will we measure whether it is working, and when would we stop?

This page is general information, not medical or legal advice. Laws and evidence change; we show the date we last checked the facts at the top of every page. Talk to your doctor or pharmacist before starting, stopping or changing any medicine.

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