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Can you overdose on CBD?

No fatal overdose from CBD alone appears in the sources we reviewed, but too much can cause sleepiness and diarrhoea. What to do, and when to call 13 11 26.

Facts checked 13 November 20266 min readHow we research

A fatal overdose from CBD alone does not appear in any of the sources we reviewed, and volunteers in studies have taken single doses of several thousand milligrams.12 Taking too much can still make you unwell, mainly with sleepiness and diarrhoea.2 The more serious risks come from what else is involved: other medicines, alcohol, or a product that contains THC or something else not on the label.

If you think someone has taken too much of any medicine or cannabis product, call the Poisons Information Centre on 13 11 26, at any time.3 Call 000 if the person has collapsed, is hard to wake or is having trouble breathing.

How much CBD has been given in studies?

Study or source Dose Who What happened
Australian product information for Epidyolex2 6,000 mg, single dose (over 85 mg per kg for a 70 kg adult) Healthy adults Mild to moderate diarrhoea and sleepiness, which resolved by the end of the study
Abuse-potential study1 750, 1,500 and 4,500 mg, single doses Adults who used drugs recreationally No high. Ratings similar to placebo
Dependence study1 1,500 mg a day for 28 days Adults No withdrawal symptoms after stopping
Liver study, 20214 1,500 mg a day for about 3.5 weeks 16 healthy adults 7 (44%) had raised liver enzymes. 6 stopped early. Some had fever, nausea or abdominal discomfort

For scale, the prescription doses used for severe epilepsy are 10 to 25 mg per kg a day, or roughly 700 to 1,750 mg a day for a 70 kg adult.1 The ceiling Australia set for pharmacist-only CBD is 150 mg a day.5

These studies were done under medical supervision with pharmaceutical-grade CBD. They show what happened to small groups of screened volunteers. They are not a guide to what is safe for any one person. A prescriber sets the dose. See CBD dosage: what trials used and how prescribers decide.

What are the signs of taking too much?

The Australian product information says experience with doses above the recommended range is limited. The symptoms it lists are diarrhoea and somnolence (sleepiness).2

Other effects that became more common at higher doses in the epilepsy trials include reduced appetite and rash.1 See CBD side effects.

The product information does not name a specific antidote. It says a person who has overdosed should be observed and given treatment for their symptoms, with their vital signs monitored.2

Why is “not lethal” not the same as “safe”?

Animal data are limited. The WHO’s review says CBD has “relatively low toxicity”, while noting that not all potential effects have been explored. In monkeys, significant effects appeared only at extremely high doses, above 30 mg per kg by mouth daily for 90 days or above 150 mg per kg into a vein.6

The liver responds to dose. Raised liver enzymes are the main dose-related harm. At prescription doses, 17% of people on 20 mg per kg a day had a significant rise, against 1% on 10 mg per kg a day.1 In healthy adults taking about 350 to 400 mg a day, it was 5.6%.7 These rises were seen with repeated daily dosing over weeks, and they usually cause no symptoms. See CBD and the liver.

Other substances add up. The prescribing information warns that alcohol and other sedating medicines may increase sleepiness.1 CBD also raises blood levels of some medicines, so an excess of CBD can mean an excess of something else. See CBD drug interactions.

Food changes the dose that reaches your blood. A high-fat meal raises peak CBD blood levels about 5-fold compared with an empty stomach.1 The same number of milligrams can therefore have quite different effects on different days. See Taking CBD with food.

Some people clear CBD slowly. People with moderate or severe liver impairment had 2.5 to 5.2 times the usual CBD blood levels after the same dose.1

CBD lingers. Its half-life after repeated dosing is 56 to 61 hours, so the effects of a large dose can take days to wear off.1

Is the product really just CBD?

This is where most real-world harm comes from. Researchers who analysed commercial CBD products have reported THC contamination.8 In one United States study of 84 CBD products bought online, only 31% were accurately labelled.9

THC is far more likely than CBD to cause a frightening reaction. The TGA lists confusion, hallucinations, paranoia and psychosis among the effects linked to THC-rich products.10 Symptoms such as feeling intoxicated, a racing heart, panic or hallucinations after a “CBD” product point to something other than CBD.

Prescription products dispensed in Australia have tested close to their labels in TGA laboratory checks.11 Products bought online, overseas or informally carry no such assurance. See Is what is on the label in the bottle? and Buying CBD online in Australia.

Children and pets

Children. The serious cannabis poisonings in children described in the research we reviewed involved edibles containing THC or delta-8-THC, not pure CBD.12 Because labels are unreliable, any gummy, oil or chocolate swallowed by a child should be treated as a possible THC exposure. Call 13 11 26, or 000 in an emergency.3 See CBD for children and teenagers.

Pets. THC is toxic to dogs. In a study of 223 dogs with THC poisoning, 88% had loss of coordination and 46% had urinary incontinence.13 Contact a vet straight away if a pet eats any cannabis product. See Pet safety.

Keep all CBD and cannabis products locked away and in their original containers.

What to do if someone has taken too much

  1. Check for danger signs. If the person has collapsed, is having a seizure, is very hard to wake or is struggling to breathe, call 000.
  2. Call the Poisons Information Centre on 13 11 26. It operates at any time.3 The Australian product information for Epidyolex directs people to the same number for overdose advice.2
  3. Have the details ready. The product and its strength, roughly how much was taken and when, the person’s age and weight, and any other medicines or alcohol involved.
  4. Keep the packaging. It helps identify what is actually in the product.
  5. Tell the prescriber or pharmacist afterwards, so they can review whether any follow-up, such as a blood test, is needed.

Suspected side effects of any medicine can also be reported to the TGA.14

What we do not know

We found no study that set out to find the maximum safe dose of CBD in people. The statement that no fatal overdose was found reflects the documents we reviewed. It is not a guarantee. Data in children, older adults, pregnant women and people with liver disease are especially thin. See Who should not take CBD?.

Footnotes

  1. Jazz Pharmaceuticals. Epidiolex (cannabidiol) oral solution, US prescribing information, DailyMed (accessed November 2026). https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=8bf27097-4870-43fb-94f0-f3d0871d1eec ↩ ↩2 ↩3 ↩4 ↩5 ↩6 ↩7 ↩8 ↩9 ↩10

  2. Therapeutic Goods Administration. Epidyolex (cannabidiol) Australian Product Information, version attached to the AusPAR, January 2021 (may be superseded). https://www.tga.gov.au/sites/default/files/auspar-cannabidiol-210115-pi.pdf ↩ ↩2 ↩3 ↩4 ↩5 ↩6

  3. healthdirect. Poisoning (Poisons Information Line 13 11 26). https://www.healthdirect.gov.au/poisoning ↩ ↩2 ↩3

  4. Watkins PB, Church RJ, Li J, Knappertz V. Cannabidiol and abnormal liver chemistries in healthy adults: results of a phase I clinical trial. Clinical Pharmacology and Therapeutics, 2021. https://pmc.ncbi.nlm.nih.gov/articles/PMC8246741/ ↩

  5. Therapeutic Goods Administration. Over-the-counter access to low dose cannabidiol (final scheduling decision), 15 December 2020. https://tga.gov.au/node/284859 ↩

  6. World Health Organization Expert Committee on Drug Dependence. Cannabidiol (CBD) critical review report, 2018. https://cdn.who.int/media/docs/default-source/controlled-substances/whocbdreportmay2018-2.pdf ↩

  7. JAMA Network. News release on Florian J and others, cannabidiol and liver enzyme level elevations in healthy adults, JAMA Internal Medicine, 7 July 2025. https://www.eurekalert.org/news-releases/1089832 ↩

  8. Quantitative analysis of THC contamination in commercial CBD products. https://pmc.ncbi.nlm.nih.gov/articles/PMC9899037/ ↩

  9. Bonn-Miller and others. Labelling accuracy of 84 cannabidiol products sold online. JAMA, 2017. https://jamanetwork.com/journals/jama/fullarticle/2661569 ↩

  10. Therapeutic Goods Administration. Guidance for the use of medicinal cannabis in Australia: patient information, version 1, December 2017. https://www.tga.gov.au/sites/default/files/guidance-use-medicinal-cannabis-australia-patient-information.pdf ↩

  11. Therapeutic Goods Administration. Testing of medicinal cannabis products being supplied under the SAS in Australia. https://www.tga.gov.au/resources/publication/tga-laboratory-testing-reports/testing-medicinal-cannabis-products-being-supplied-sas-australia ↩

  12. Review of paediatric cannabis edible exposures. Frontiers in Toxicology, 2024. https://www.frontiersin.org/articles/10.3389/ftox.2024.1371651/full ↩

  13. Study of 223 dogs with THC toxicosis. Journal of the American Veterinary Medical Association, 2024. https://pubmed.ncbi.nlm.nih.gov/38608656/ ↩

  14. Therapeutic Goods Administration. Reporting problems. https://www.tga.gov.au/reporting-problems ↩

Common questions

What happens if you take too much CBD?

The symptoms reported after very large single doses are diarrhoea and sleepiness. In a study, healthy adults who took 6,000 mg at once had mild to moderate diarrhoea and sleepiness that resolved. The effects may be stronger if alcohol or sedating medicines are involved, or if the product also contains THC.

Can CBD kill you?

No death from CBD alone was identified in any of the sources we reviewed, and volunteers have been given single doses of several thousand milligrams in studies. That does not make very large doses safe. Risks rise with other medicines, liver disease and contaminated products.

I accidentally took a double dose of my CBD. What should I do?

Call the Poisons Information Centre on 13 11 26 for advice specific to your dose, product and other medicines. The line answers at any time. Tell your prescriber or pharmacist as well, and call 000 if someone is very drowsy, hard to wake or having trouble breathing.

My child or pet swallowed a CBD product. Is that an emergency?

Treat it as urgent, because the product may contain THC even if the label says CBD. For a child, call the Poisons Information Centre on 13 11 26, or 000 in an emergency. For a pet, contact a vet straight away.

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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