General Information
This section provides general information about illicit cannabis use in Australia. It explains what cannabis is, how it is used, the effects of use and associated health risks.
Information in this section is sourced from a variety of websites. Please refer to specific FAQs for source information.
What is cannabis?
Cannabis (or marijuana) is a drug derived from one of three species of cannabis plants (Cannabis sativa, Cannabis indica, and Cannabis ruderalis). There are also lab-made versions of cannabis (“synthetic cannabanoids”) which are manufactured to contain similar chemical compounds.
Cannabis is a depressant drug which reduces brain activity. There are more than 500 chemical compounds in cannabis, but the main psychoactive component is delta-9-tetrahydrocannabinol (THC). When cannabis is used, THC is the main active chemical constituent absorbed into the bloodstream, activating receptors in the brain to produce the associated “high”.
There are three main forms of illicit cannabis: the dried leaves and flowers (heads), hashish (made from the resin of the plant), and hash oil. Cannabis is usually smoked in hand-rolled cigarettes (known as ‘joints’), in pipes or special water pipes (‘bongs’), or mixed with tobacco. It can also be added to food and eaten.
Please note that the NADK focusses on illicit (i.e. non-medical) cannabis use; for information related to medicinal cannabis in Australia, please refer to the Therapeutic Goods Administration Medicinal Cannabis Hub.
AIHW (2025) Alcohol, tobacco & other drugs in Australia, NIDA (2024) Cannabis (Marijuana), SA Health (2017) What is Cannabis, and Rock EM, Parker LA. Constituents of Cannabis Sativa. Adv Exp Med Biol. 2021;1264:1-13.
What are the short-term effects of cannabis use?
The immediate effects of illicit cannabis use may include a general feeling of wellbeing and relaxation, and an altered perception of time. People who use cannabis may be talkative, or feel hungry or drowsy. Some people who use cannabis feel restless, irritable or anxious. Cannabis use can also impair thinking, memory, and concentration. Body movement and coordination are also impaired after using cannabis, and reaction time increases. Other effects of cannabis use include a dry mouth, bloodshot eyes, and increases in heart rate and blood pressure.
Source: NIDA (2024) Cannabis (Marijuana), SA Health (2017) What is Cannabis.
What negative consequences does cannabis use have for Australian workplaces?
Cannabis use is associated with a range of negative outcomes for the workplace, including accidents, injuries, absenteeism and low productivity.
Cannabis use can impair:
· short-term memory
· cognition
· balance and coordination
· concentration
· sensory perception
· ability to perform complex tasks
· alertness and reaction time.
These effects can last between two and six hours and can negatively affect workplace safety, performance and productivity. Employees who use cannabis can present a potential danger at work, especially if the user is operating machinery or driving a vehicle.
In 2015/16, the cost to Australian businesses due to cannabis-related occupational injury and absenteeism was estimated to exceed $560 million.
Source: McEntee A, Roche A, Whetton S. Chapter 6: Workplace costs. In: Tait RJ, Allsop, S. (Eds.)., Quantifying the Social Costs of Cannabis Use to Australia in 2015/16. Perth, WA: National Drug Research Institute, Curtin University; 2020.
Where can I get help or more information about cannabis?
If you are worried about your own or somebody else’s cannabis use, contact the Alcohol and Drug Information Service (ADIS). The Alcohol and Drug Information Centres are state and territory-based services that offer information, advice, referral, intake, assessment and support. They offer services for individuals, their family and friends, general practitioners, other health professionals, and business and community groups.
To contact ADIS, ring the 24 hour hotline on 1800 250 015 and you will be automatically directed to the ADIS in the state or territory you are calling from.
Source: Australian Government. Alcohol and Drug Information Service website.