Can I drive on Medical Marijuana?

Can I drive on Medical Marijuana?  This is an important question and one that we get asked frequently.  However, the answer is not a simple yes or no, but very much “it depends”. 

For anyone taking Medicinal Marijuana (Medical Cannabis), it is essential to know what the product is made of (what forms of Cannabis are in the product) and to understand drug driving laws in Australia.

For context:  In 2016 the Federal Government legalised the cultivation of medicinal cannabis with an approved permit.  Since then, steady changes to policy have been made in Australian states and territories, including official approval of one Medicinal Cannabis product by the Therapeutic Goods Administration (TGA).  Patients can now legally access Medical Cannabis products through a doctor in Australia, even products that have not been officially approved by the TGA. 

Regardless of the legal and policy changes in recent years, it is important to be aware that it is still illegal to drive with any detectable level of d-THC (the main active ingredient in cannabis) in your system in all states and territories of Australia.  This is based on multiple studies demonstrating the potential for d-THC to cause impairment of driving skills.

Detection of THC in roadside testing

Roadside drug tests in Australia aim to detect the presence of certain drugs, including d-THC, the psychoactive compound in marijuana. The method of drug testing used in the roadside drug testing programs is saliva testing.  Saliva testing for drugs is easy to administer roadside, is less invasive than other forms of testing, and in the case of THC, only detect recent use of the drug.  Roadside drug testing for THC does not detect historical use, for example a few weeks ago, as is the case for urine testing.  This is because it is the recent use of THC that is most likely to contribute to driving impairment.

CBD (Cannabidiol) is another compound found in marijuana, but it does not produce the same psychoactive effects as d-THC.  Roadside drug tests are not designed to specifically detect CBD.  However, it's important to note that some "CBD only" products may contain trace amounts of d-THC, especially if derived from the Cannabis plant. In rare cases, consuming large amounts of such products might lead to a positive THC test result. Additionally, the quality and composition of CBD products can vary, so it's crucial to choose products from reputable sources that provide detailed information about their contents.

But what about Medical Marijuana? 

Medical Marijuana (Cannabis) is increasingly being considered and utilised for various health conditions due to its potential therapeutic benefits.  Although there are limited studies proving its effectiveness, Medical Marijuana is already used by an increasing number of people for pain management, nausea and vomiting, stimulating appetite, muscle spasms, and seizure disorders amongst others.

Medicinal Marijuana commonly contains one of two main active ingredients:  d-9 THC or CBD (Cannabidiol), or it may contain a combination of the two.  Current evidence demonstrates that d9-THC can cause impairing effects on driving due to its psychoactive nature.  CBD, on the other hand, is not a psychoactive substance.  As mentioned, roadside saliva drug tests are designed to detect d-9 THC only.  If the medicinal cannabis product does not contain any d-9 THC, then it won’t be detected in a roadside test. 

It is essential to be well informed on the ingredients in the Medicinal Marijuana product, and to ensure it is a CBD only product, if driving is to be considered.  However, there are currently few CBD only products available and access can be challenging.  Producing a Doctor's prescription is not a valid defence for a roadside THC detection. This should be done in consultation with your prescribing doctor, and to check if there are any other factors that should be taken into account before driving is considered.

With an increasing number of people using medical marijuana in Australia every year, how can policy and law makers balance the road safety challenges of people using medicines that have the potential to cause driving impairment with human rights?  Recently, in November 2023, a new bill was introduced to the Victorian Parliament, designed to support studies designed to investigate the effects of medicinal cannabis on driving. (  The Minister for Roads and Road Safety, Melissa Horne said the main purpose of the bill was to allow the conduct of a world leading research trial into medicinal cannabis and driving.  ‘While this is a road safety challenge, it is also an issue of human rights – we currently have a situation where Victorians are forced to choose between taking prescribed medicinal cannabis to treat medical conditions and being able to drive,’ she said.  “This Bill will allow us to deliver a world-leading research trial into medicinal cannabis and driving, enhancing our understanding of the how medicinal cannabis affects driving behaviour and informing future reform.”

Determining the effects of Medical Marijuana on driving is a complex, and important area of research.  It is likely that findings and recommendations from any studies will be some time away.  In the meantime, drug driving laws around Cannabis in Australia remain the same. 

For anyone considering or currently taking Medical Marijuana, it is essential to be informed about the ingredients contained in the medicine, and whether these have the potential to be detected in a roadside drug test.  It is also equally important to consult with your Doctor or Specialist to understand the risks to driving from both your condition, and the use of the medicine in order to protect both your own safety and the safety of other road users.



The information provided in this article is of a general nature only.  Individuals looking for specific advice should consult with their healthcare professional and the TAC website:

Drug driving lawsMedical cannabisMedical marijuanaRoadside drug testing

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