Medicinal cannabis, explained

There is a lot of interest in the use of cannabis as a medicine. Find answers to some of your questions about the new medicinal cannabis products, their legal status and what they can be used for.


What is medicinal cannabis?

Cannabis is a flowering plant in the Cannabaceae family. Humans have been growing and using cannabis for multiple purposes over thousands of years.

Medicinal cannabis products are mostly made from chemicals found in the cannabis plant. These are called phytocannabinoids (in Greek, phyto means ‘of a plant’).

Some medicinal cannabis products are produced synthetically in a laboratory to mimic the actions of phytocannabinoids. These are called synthetic cannabinoids.

Some synthetic cannabinoids can have more harmful side effects than phytocannabinoids, and when used have resulted in a number of deaths.

How does medicinal cannabis work?

Cannabis contains chemicals called phytocannabinoids (commonly referred to as cannabinoids). There are more than 100 different types of cannabinoids found in cannabis plants.

Cannabinoids can also be found in the human body. These are called endocannabinoids and they affect appetite, sleep, memory, pain and inflammation.

Cannabinoids from the cannabis plant act on receptors in the brain and other parts of the body by mimicking naturally occurring endocannabinoids.

Two of the most common cannabinoids used in medicinal cannabis products are THC (delta 9-tetrahydrocannabinol) and CBD (cannabidiol). These work differently. 

  • THC may be used to reduce symptoms of nausea, vomiting, pain and muscle spasticity as well as improve sleep and appetite. In some people, THC may cause the ‘high’ generally associated with recreational cannabis use.
  • CBD does not cause a ‘high’ and may reduce the unwanted side effects of THC.
  • Research is continuing into the medicinal uses of CBD and THC combined. The combination is thought to be useful in the management of seizures and pain and may also help to reduce anxiety.

Medicinal cannabis is not considered a ‘first-line’ treatment for any health condition. Treatment with medicinal cannabis should only be considered by a prescribing doctor once all other standard approved treatments have been unsuccessful.

Is medicinal cannabis the same as recreational cannabis?

No. Medicinal cannabis is different from recreational cannabis (also known as marijuana).

  • Medicinal cannabis is a therapeutic good, which means it is regulated to ensure its safety.
  • Medicinal cannabis producers must comply with Australian standards for producing pharmaceutical-grade medicines.
  • Pharmaceutical-grade medicinal cannabis products are cultivated and manufactured to meet stringent Australian quality and safety standards.
  • Medicinal cannabis products must contain known quantities of the cannabinoids THC and CBD.
  • Products must not contain any moulds, fungi, bacteria, pesticides, heavy metals or other potentially harmful substances.

What are some of the conditions for which medicinal cannabis treatment has been approved?

In Australia, the Therapeutic Goods Administration (TGA) has approved applications for the use of medicinal cannabis to treat conditions including:

  • nausea and vomiting due to chemotherapy
  • epilepsy in children
  • palliative care
  • cancer pain
  • neuropathic pain
  • spasticity from conditions such as multiple sclerosis
  • anorexia and wasting associated with chronic illness such as cancer.

Find out more about the conditions where medicinal cannabis may be effective by visiting the TGA website.

Who can prescribe medicinal cannabis?

Medicinal cannabis is subject to laws and regulations in Australia.

Because medicinal cannabis is not considered a ‘first line’ treatment for any condition, it should only be considered by a prescribing doctor if the usual approved treatments have not worked effectively.

If your doctor is considering prescribing medicinal cannabis after you have tried all other usual approved treatments without success, they should read a summary of the evidence and assess whether medicinal cannabis may be effective for your health condition.

Prescribing doctors must apply for approval to prescribe the product from the Australian government regulatory authority and state/territory health departments (if required).

Download our guide to the approval process and how to access medicinal cannabis 


Your doctor can download our guide to the process for prescribers

How do I take medicinal cannabis?

Medicinal cannabis is not considered to be a ‘first line’ treatment for any health condition. It should only be considered as a treatment if the usual approved treatments have not worked effectively.

Before starting any medicine, seek advice from your doctor or pharmacist about how much to take, how to take it and what side effects you need to be aware of.

If you have been prescribed medicinal cannabis, always take the dose (amount) as directed.

Medicinal cannabis products can be taken in several ways:

  • sprayed into the mouth or under the tongue
  • by swallowing oils, liquid capsules or tablets
  • via vaporising by heating the cannabis and inhaling the vapour.

A variety of vaporising devices are on the market, but most of them are not approved for therapeutic use. If you are considering using a vaporising device, it is recommended that you only use devices that have been tested and found to be safe. Your doctor can check with the TGA about how to access unapproved vaporising devices.

Smoking cannabis products is not recommended. Smoking increases the risk of cancer, stroke, heart disease and other serious health conditions.

What are the side effects of medicinal cannabis?

Like all medicines, medicinal cannabis products can have side effects. 

The known side effects from medicinal cannabis treatment include 

  • fatigue and sedation
  • dizziness
  • confusion
  • nausea and vomiting
  • fever
  • decreased or increased appetite
  • dry mouth, and 
  • diarrhoea.

Products high in tetrahydrocannabinol (THC) have been associated with 

  • feeling ‘high’ or feeling dissatisfied
  • depression
  • confusion
  • hallucinations
  • paranoid delusions
  • psychosis, and 
  • cognitive distortion (having thoughts that are not true).

Medicinal cannabis side effects are commonly dose-dependent, so it’s important to follow the dosing recommendations.

Medicinal cannabis products should only be taken under medical advice because they may interact with other medicines or cause side effects.

What should I do if I experience side effects?

If you have experienced a medicine-related side effect or adverse event, you must contact your doctor. If the side effect or event is serious, seek medical advice.

If you have experienced a serious cannabis-related side effect, your doctor is required to report the event to the TGA within 15 calendar days.

If you have concerns about your medicines arising from an overdose or suspected poisoning, call the Poisons Information Centre 24 hours a day on 13 11 26.

For emergencies, call 000.

You can also report medicine-related side effects through the Adverse Medicine Events Line by calling 1300 134 237 from anywhere in Australia (Monday to Friday 9am to 5pm AEST excluding public holidays).

Adverse events can also be reported online to the TGA via their Adverse Events reporting page.

What are the risks of buying medicinal cannabis online?

Medicines that are not regulated by the TGA, and can be ordered from overseas, carry a number of risks.

  • They may be counterfeit and contain no active ingredients.
  • They may contain unknown amounts of the active ingredient and either be too weak to help you, or strong enough to harm you.
  • They may be contaminated or adulterated with toxic substances.
  • They may contain undisclosed or dangerous ingredients.

Australia has a very good system for maintaining the safety and quality of medicines that are sold here.

Medicinal cannabis is being regulated as a medicine in Australia to ensure the safety of the people for whom it is prescribed.

Even if they have an authorised prescription, it is illegal for an individual to personally order medicinal cannabis products online, or to import medicinal cannabis for personal use.

The licence to import will only be issued by the Office of Drug Control to doctors or pharmacists.

For more information download our medicinal cannabis FAQs

Where can I go for more information?