In short
Medicinal cannabis is legal in Australia on prescription, but tightly regulated. Almost every product is an unapproved medicine, which means the regulator has not assessed whether it works or how safe it is. It is not a first-line treatment for any condition. The evidence is strongest for a few rare epilepsies and some multiple sclerosis symptoms, and modest at best for chronic pain. Side effects are common, and driving with THC in your system is an offence in most states even with a prescription.
On this page
What is medicinal cannabis?
Medicinal cannabis is a cannabis product prescribed by a registered health practitioner to relieve the symptoms of some medical conditions.1 You may also see it called medical cannabis or medical marijuana.
The cannabis plant contains around 130 substances called cannabinoids. Two matter most:1
- THC (tetrahydrocannabinol) has strong effects on the mind. It is the chemical that makes a person feel "high".
- CBD (cannabidiol) does not cause a high.
Medicinal cannabis is not the same thing as cannabis bought illegally. Prescribed products are pharmaceutical grade, and the label shows how much THC and CBD they contain. Illegal cannabis can contain unknown amounts of cannabinoids and harmful impurities.1
Oils, capsules, sprays and dried plant material
Prescribed products come in several forms, including capsules and mouth sprays.1 Oils taken by mouth are the most commonly prescribed type in Australia, and approvals for dried flower products rose markedly in 2020 and 2021.6 In a 2020 survey of Australians using cannabis for medical reasons, 72 per cent of people with a prescription took it by mouth.28
What people call cannabis oil or THC oil is usually one of these measured liquids. An oil bought outside a pharmacy is a different thing. Nobody has checked what is in it, and buying it is against the law.1,3
Is medicinal cannabis legal in Australia?
Yes, with a prescription. The Australian Government changed the law in October 2016 to allow cannabis to be used as a medicine.1 It remains highly regulated:
- You can only get it through a prescription from a doctor or nurse practitioner, or by taking part in a clinical trial.1,3
- It has to be dispensed by a pharmacy. Getting it from a tobacconist, vape shop, convenience store or an online store that is not a registered pharmacy is breaking the law.3
- Importing it yourself by mail or courier is illegal.1
- Growing your own is illegal, even with a prescription. The ACT has separate rules about a small number of plants for personal use.1
Approved and unapproved products
This distinction matters. Only two cannabis medicines are registered in Australia. One is a mouth spray containing equal parts THC and CBD, used for muscle stiffness in multiple sclerosis. The other is a CBD-only liquid used alongside other medicines for rare, severe childhood epilepsies.5 The epilepsy medicine is the only cannabis product subsidised on the Pharmaceutical Benefits Scheme.1
Everything else is an unapproved medicine. That covers more than 99 per cent of the medicinal cannabis prescribed in Australia, across more than 1,000 different products.5
Unapproved has a specific meaning. The Therapeutic Goods Administration (TGA), which regulates medicines, has not assessed these products for safety, quality or effectiveness.2 In the TGA's own words to patients, a prescription does not mean the product has been assessed and approved.4
Before prescribing one, your doctor should explain that the product is unapproved and why it is being considered for you, give you the chance to ask questions, and get your informed consent.4
How prescribing works
Medicinal cannabis is not recommended as a first-line treatment for any health condition in Australia. Doctors usually only consider it when other treatments have not worked.1,5
- A consultation. A doctor or nurse practitioner looks at your condition, what you have already tried and your other medicines, and decides whether it is appropriate. They may decide there is not enough evidence to support using it for your condition.3
- Government approval. For an unapproved product, the prescriber has to get the necessary approval or authorisation from the TGA first.1
- A prescription. You take it to a pharmacy to be dispensed.1
- A review. The TGA suggests starting with a one-month trial to see whether it is helping.1
The Royal Australian College of General Practitioners describes the current evidence for medicinal cannabis as limited and inconclusive, and has called for more high-quality research.18
What does the evidence say?
Most research has looked at a handful of conditions. The results are more modest than the publicity suggests.
| Condition | What trials have found |
|---|---|
| Rare childhood epilepsies | The strongest evidence. In one trial of CBD in Dravet syndrome, convulsive seizures fell from a median of 12.4 a month to 5.9, compared with 14.9 to 14.1 on placebo.7 In Lennox-Gastaut syndrome, drop seizures fell by 43.9 per cent with CBD and 21.8 per cent with placebo.8 |
| Multiple sclerosis | A review of 17 trials found limited benefit for muscle stiffness, pain and bladder problems.9 |
| Nausea from chemotherapy | May help when other treatments have failed. The trials were run between 1975 and 1991 and none compared cannabis medicines with newer anti-nausea medicines.10 |
| Chronic pain | A small effect. In one review, 29.0 per cent of people on cannabinoids had a 30 per cent drop in pain, compared with 25.9 per cent on placebo. About 24 people had to be treated for one to benefit.11 A 2021 review found small to very small improvements in pain, physical function and sleep quality.12 |
| Nerve pain | A Cochrane review concluded that the possible benefits might be outweighed by the possible harms.14 |
| Anxiety, depression, PTSD and ADHD | A review of 83 studies found scarce evidence that cannabinoids improve any of them.16 |
| Sleep problems | Low-quality evidence overall.17 |
Expert groups read this evidence differently. An international guideline panel made a weak recommendation to offer a trial of non-inhaled medicinal cannabis to people with chronic pain when standard care has not been enough, because the benefits and harms are closely balanced.13 The International Association for the Study of Pain does not endorse the general use of cannabinoids for pain, citing the lack of high-quality evidence.15
Side effects and risks
Like all medicines, medicinal cannabis has side effects. Common ones include:1
- Drowsiness and fatigue
- Dizziness or vertigo
- Confusion or a sense of unease
- Nausea, vomiting and diarrhoea
- Dry mouth and changes in appetite
In chronic pain trials, 81.2 per cent of people taking cannabinoids reported a side effect, compared with 66.2 per cent on placebo.11 Dizziness, drowsiness and nausea were among the side effects that were more common than on placebo.12
Side effects are generally fewer with CBD than with THC.5,19 CBD can still interact with other medicines, so your prescriber needs a full list of what you take.20
Who should be most careful with THC
- People with a personal or family history of psychosis. An Australian review written for GPs says THC products should not be prescribed to them.19
- People with angina or a previous heart attack.19
- Children and teenagers. THC can impair thinking, and the same review says it is best avoided unless the benefits outweigh the risks.19
- Anyone pregnant or breastfeeding. Regular cannabis use in pregnancy may affect a baby's development, and CBD passes into breast milk.30,31
People who use cannabis regularly can become dependent on it and have withdrawal symptoms when they stop.21
Medicinal cannabis and driving
Do not drive or operate machinery while using a product that contains THC. THC affects your ability to drive and raises your risk of a crash. The effect can last up to 8 hours after an oral dose.1 A review of 80 studies estimated that most driving-related skills recover within about 5 hours of inhaling a 20 mg dose of THC, and that oral doses may take longer.29
The law is a separate question from impairment. Roadside tests look for the presence of THC, not whether you are affected, and they can pick it up well after the effects have worn off.22 In most of Australia you can be charged if THC is found in your system while driving, whether or not you have a prescription.3
The rules differ by state and are changing:
- Tasmania: driving with THC in your system is not an offence if the product was obtained and taken in line with the state's poisons law. Driving while impaired is always an offence.23
- Victoria: it is still an offence, but if you have a valid prescription the magistrate can decide whether you lose your licence.24
- New South Wales: Parliament passed a law in September 2026 that will let registered patients with an unrestricted licence avoid automatic penalties if they are not impaired and meet strict conditions. The register and the compulsory education course are expected in late 2026 or early 2027. It does not cover learner, provisional or commercial drivers.25,26
- Queensland: driving with any trace is an offence, including medicinal cannabis.27
CBD-only products can cause drowsiness.1 Some products that do not list THC as an ingredient still contain traces of it.3
What does it cost?
Apart from the one epilepsy medicine, medicinal cannabis is not subsidised, and the cost can run to thousands of dollars a year depending on the product and dose.1 In a 2020 Australian survey, people using cannabis for medical reasons spent an average of $74 a week on it, and half spent $40 or less.28
How many Australians use it?
In 2022 to 2023, around 700,000 Australians were estimated to use cannabis for medical reasons. Only 29.9 per cent of them had a prescription for it at least some of the time.5 Among people with a prescription in the 2020 survey, 52 per cent were treating a pain condition, 26 per cent a mental health condition and 6 per cent a sleep condition.28
When to talk to a doctor
If you have a condition that has not responded to the usual treatments and you are wondering whether medicinal cannabis is an option, talk it through with a doctor. Useful questions to ask:1
- Is there evidence it helps my condition?
- Is it safe for me, given my health and my other medicines?
- What side effects should I expect?
- Will I be able to drive, work or look after my children while taking it?
A doctor may recommend something else. That is a normal outcome, and for most conditions other treatments have better evidence.
See also our guides to THC and CBD, CBD oil in Australia and cannabis and the law.
References
- healthdirect. Medicinal cannabis.
- Therapeutic Goods Administration. Medicinal cannabis hub.
- Therapeutic Goods Administration. Medicinal cannabis: information for consumers.
- Therapeutic Goods Administration. What to know if you've been prescribed medicinal cannabis.
- Alcohol and Drug Foundation. Medicinal cannabis products.
- MacPhail SL, Bedoya-Pérez MA, Cohen R, et al. Medicinal Cannabis Prescribing in Australia: An Analysis of Trends Over the First Five Years. Front Pharmacol. 2022;13:885655.
- Devinsky O, Cross JH, Laux L, et al. Trial of Cannabidiol for Drug-Resistant Seizures in the Dravet Syndrome. N Engl J Med. 2017;376(21):2011-2020.
- Thiele EA, Marsh ED, French JA, et al. Cannabidiol in patients with seizures associated with Lennox-Gastaut syndrome (GWPCARE4): a randomised, double-blind, placebo-controlled phase 3 trial. Lancet. 2018;391(10125):1085-1096.
- Torres-Moreno MC, Papaseit E, Torrens M, et al. Assessment of Efficacy and Tolerability of Medicinal Cannabinoids in Patients With Multiple Sclerosis: A Systematic Review and Meta-analysis. JAMA Netw Open. 2018;1(6):e183485.
- Smith LA, Azariah F, Lavender VT, et al. Cannabinoids for nausea and vomiting in adults with cancer receiving chemotherapy. Cochrane Database Syst Rev. 2015;2015(11):CD009464.
- Stockings E, Campbell G, Hall WD, et al. Cannabis and cannabinoids for the treatment of people with chronic noncancer pain conditions: a systematic review and meta-analysis of controlled and observational studies. Pain. 2018;159(10):1932-1954.
- Wang L, Hong PJ, May C, et al. Medical cannabis or cannabinoids for chronic non-cancer and cancer related pain: a systematic review and meta-analysis of randomised clinical trials. BMJ. 2021;374:n1034.
- Busse JW, Vankrunkelsven P, Zeng L, et al. Medical cannabis or cannabinoids for chronic pain: a clinical practice guideline. BMJ. 2021;374:n2040.
- Mücke M, Phillips T, Radbruch L, et al. Cannabis-based medicines for chronic neuropathic pain in adults. Cochrane Database Syst Rev. 2018;3(3):CD012182.
- IASP Presidential Task Force on Cannabis and Cannabinoid Analgesia. International Association for the Study of Pain Presidential Task Force on Cannabis and Cannabinoid Analgesia position statement. Pain. 2021;162(Suppl 1):S1-S2.
- Black N, Stockings E, Campbell G, et al. Cannabinoids for the treatment of mental disorders and symptoms of mental disorders: a systematic review and meta-analysis. Lancet Psychiatry. 2019;6(12):995-1010.
- Whiting PF, Wolff RF, Deshpande S, et al. Cannabinoids for Medical Use: A Systematic Review and Meta-analysis. JAMA. 2015;313(24):2456-73.
- Royal Australian College of General Practitioners. Use of medicinal cannabis products (position statement).
- Arnold JC. A primer on medicinal cannabis safety and potential adverse effects. Aust J Gen Pract. 2021;50(6):345-350.
- Chesney E, Oliver D, Green A, et al. Adverse effects of cannabidiol: a systematic review and meta-analysis of randomized clinical trials. Neuropsychopharmacology. 2020;45(11):1799-1806.
- healthdirect. Cannabis (marijuana).
- Alcohol and Drug Foundation. Roadside drug testing.
- Tasmanian Department of Health. Medicinal cannabis information for patients and the general public.
- Victoria Legal Aid. Drug driving.
- NSW Government. Medicinal cannabis driving reforms introduced to Parliament.
- NSW Government. Medicinal cannabis driving reforms pass NSW Parliament.
- Queensland Government. Drug offences.
- Lintzeris N, Mills L, Abelev SV, et al. Medical cannabis use in Australia: consumer experiences from the online cannabis as medicine survey 2020 (CAMS-20). Harm Reduct J. 2022;19(1):88.
- McCartney D, Arkell TR, Irwin C, et al. Determining the magnitude and duration of acute Δ(9)-tetrahydrocannabinol (Δ(9)-THC)-induced driving and cognitive impairment: A systematic and meta-analytic review. Neurosci Biobehav Rev. 2021;126:175-193.
- Alcohol and Drug Foundation. CBD (Cannabidiol).
- Alcohol and Drug Foundation. Cannabis (THC).
This guide is general information, not medical advice. It doesn’t replace a consultation with a doctor who knows your history. In an emergency, call 000.