Cannabis may reduce tics in some adults with Tourette syndrome, but the evidence is limited: a handful of small randomized trials of THC or THC-plus-CBD found modest improvement, while the largest trial, of the spray nabiximols, missed its main goal. No cannabis product is approved for Tourette syndrome, and side effects such as slowed thinking and poor concentration were common in the trials.
Tourette syndrome causes repeated, involuntary movements and sounds called tics, often alongside ADHD, obsessive-compulsive symptoms or anxiety. Some adults with Tourette’s say cannabis calms their tics, and that experience prompted researchers in Germany, Canada and Australia to test it. This guide covers what those studies found, how strong the evidence is, and the risks, as of October 2026.
Cannabis and Tourette Syndrome: Evidence at a Glance
| Claim | Evidence level | Source |
|---|---|---|
| THC capsules improve tic severity | Limited (two small German trials) | National Academies 2017 |
| THC plus CBD oil reduces tics in severe Tourette’s | Limited to moderate (one 22-person crossover RCT) | NEJM Evidence 2023 |
| Nabiximols (THC and CBD spray) reduces tics | Mixed (97-person trial missed primary endpoint) | CANNA-TICS 2023 |
| A single dose of vaporized cannabis reduces observed tics | Not shown (pilot trial) | Abi-Jaoude et al. 2023 |
| Cannabinoids help Tourette’s overall | Scarce evidence (systematic review) | Lancet Psychiatry 2019 |
The First Trials: Hannover, Germany
Psychiatrist Kirsten Müller-Vahl at Hannover Medical School ran the first controlled studies. In 2002, a single-dose crossover trial gave 12 adults THC (5 to 10 mg) or placebo. Patients rated their tics and obsessive-compulsive behavior as significantly better after THC, and examiners saw improvement in complex motor tics (Pharmacopsychiatry, 2002).
A follow-up trial treated 24 adults with up to 10 mg of THC a day or placebo for six weeks. The authors reported a reduction in tics with THC, though seven participants dropped out or were excluded (Journal of Clinical Psychiatry, 2003). These two studies are why the National Academies in 2017 found limited evidence that THC capsules improve Tourette symptoms.
Newer Trials, 2022 to 2025
THC and CBD oil in severe Tourette’s (Australia)
The strongest result so far came from a crossover trial in Sydney, published in 2023. Twenty-two adults with severe Tourette’s took an oil containing equal amounts of THC and CBD, or placebo, for six weeks each. Total tic scores fell by 8.9 points on the active treatment versus 2.5 points on placebo, a statistically significant difference. The study also suggested possible improvement in anxiety and obsessive-compulsive symptoms. The most common side effects were cognitive: slowed thinking, memory lapses and poor concentration (Mosley et al., NEJM Evidence).
Nabiximols (CANNA-TICS, Germany)
The largest trial randomized 97 adults with Tourette’s or chronic tic disorders to nabiximols, a THC and CBD mouth spray, or placebo for 13 weeks. The main goal was a tic reduction of at least 25%. That happened in 21.9% of the nabiximols group versus 9.1% on placebo, but the difference was not large enough to be statistically conclusive. Secondary measures leaned toward benefit (Müller-Vahl et al., Psychiatry Research).
Vaporized cannabis (Canada)
A Toronto pilot gave 12 adults single vaporized doses of high-THC, balanced THC/CBD, high-CBD cannabis and placebo. None significantly changed tics measured on video, though the high-THC product improved patients’ urges and distress ratings. Most participants could tell when they got cannabis, which weakens the blinding (Abi-Jaoude et al.).
Adolescents (Australia)
A 2025 pilot in 10 teenagers aged 12 to 18 tested a THC and CBD oil. It was designed to check feasibility, not effectiveness. Three participants were rated much improved on the cannabis oil versus one on placebo; dizziness was the most common side effect. The authors said a full-size trial is needed (Cannabis and Cannabinoid Research).
How Strong Is the Evidence?
Every trial has been small, and together they include fewer than 200 people. Results lean in a positive direction, with THC appearing to be the active ingredient, but the largest study did not meet its target. A 2019 systematic review in The Lancet Psychiatry called the evidence for cannabinoids in Tourette’s scarce. Blinding is another weak point: THC has noticeable effects, so many participants can guess when they are on the active treatment, which can inflate self-rated improvement. A fair summary: promising for some adults with severe tics who have not responded to standard care, but not proven.
Standard treatments include behavioral therapy (Comprehensive Behavioral Intervention for Tics) and several medications. The Tourette Association of America has information on proven options.
Risks and Side Effects
- Thinking and concentration: the most common complaint in the trials. This matters for students and drivers.
- Dizziness and tiredness: reported in adult and teen trials.
- Anxiety and psychosis: THC can trigger anxiety and, in vulnerable people, psychotic symptoms. See our report on cannabis and schizophrenia research.
- Young people: Tourette’s usually starts in childhood. Teens who use cannabis face a higher risk of cannabis use disorder; the NCCIH notes adolescents are four to seven times more likely than adults to develop it.
- Driving: THC impairs driving. A CANNA-TICS substudy looked at driving ability specifically; anyone using THC should not drive while impaired.
- Dependence: regular use can lead to cannabis use disorder and withdrawal symptoms.
Talk to Your Doctor
Adults with severe tics that have not responded to behavioral therapy and medication can ask a neurologist or psychiatrist experienced in Tourette’s whether a cannabinoid trial makes sense. Ask about the dose, how to measure the effect (a tic diary or rating scale), and how it might interact with medicines for ADHD, OCD or anxiety. Parents should not give THC products to children outside of medical care or a clinical trial.
Legal Status
Tourette syndrome is a qualifying condition in some state medical cannabis programs but not others. Adults 21 and older can buy cannabis in adult-use states such as Washington and Oregon. Dronabinol, a synthetic THC capsule, is FDA-approved for other conditions and could be prescribed off-label. Nabiximols is not approved in the US. Cannabis remains federally illegal; see our federal law guide.
Cannabis and Tourette Syndrome FAQ
Does marijuana help tics?
Small trials suggest THC can reduce tics in some adults, but the largest trial was not conclusive. It is considered experimental, not a standard treatment.
Is CBD or THC better for Tourette’s?
The trials point to THC as the active ingredient. A high-CBD product did not improve tics in a Canadian pilot, and the positive Australian trial used equal THC and CBD.
Can kids with Tourette’s use cannabis?
Only one small feasibility study has been done in teenagers. THC carries particular risks for developing brains, so use in children should happen only under specialist care or in a trial.
How fast does cannabis work on tics?
In the 2002 study, patients reported improvement after a single THC dose, but most trials measured effects over six to 13 weeks of daily treatment.
What are the side effects of cannabis for Tourette’s?
Slowed thinking, memory lapses, poor concentration and dizziness were the most common. THC can also worsen anxiety in some people.
Related reading: cannabis and Huntington’s disease, cannabis and epilepsy, and more in our cannabis research section.
For adults 21+ in legal states. General information, not medical advice. Talk to a doctor before using cannabis for a health condition.
