Supply reduction

Supply reduction involves ‘preventing, stopping, disrupting or otherwise reducing the production and supply of illegal drugs; and controlling, managing and/or regulating the availability of legal drugs’ (DoH 2017b).

Information on the availability of alcohol, tobacco and other drugs in Australia comes from research with people who use drugs, seizure data from law enforcement agencies, wastewater analysis and information collated from international sources in relation to drug manufacturing and importation.

Legal substances

The consumption of alcohol and tobacco by adults is legal in Australia. Almost 1 in 2 (45%) Australians aged 14 years and over approved of regular adult consumption of alcohol compared with 15.4% who approved of regular tobacco use (AIHW 2020). Alcohol and tobacco products are available for purchase; however, there are a number of strict regulations that control their supply. Specific supply reduction interventions include:

  • the enforcement of a minimum purchasing age;
  • restriction of operating hours for venues supplying alcohol;
  • taxation on alcohol and tobacco products;
  • restrictions on the size and strength of beverages or the number of drinks that can be purchased at one time, and the size (minimum number of cigarettes) of cigarette packets.

Medicinal substances

Pharmaceutical drugs are available over-the-counter (OTC) or from a registered health practitioner for the treatment of illness or injury. Their supply by health practitioners is subject to strict controls in relation to quantity supplied and directions for consumption, including the provision of advice to the consumer on restricting the use of these drugs in combination with alcohol and other licit and illicit drugs (TGA 2018).

When pharmaceutical drugs are used for non-medical purposes, the drugs can be diverted or channelled from the legal supply system to the illegal marketplace for misuse. This process of diversion may occur in a number of ways such as sharing between family and friends, theft, prescription forgery, doctor shopping, illegal sale and overprescribing by health practitioners. Policies aimed at reducing the supply of pharmaceutical drugs for non-medical use in Australia, include:

  • agreement to develop a national real-time prescription monitoring system;
  • the up-scheduling of codeine so that it is available as a prescription-only medication.

In 2016, cannabis became available medicinally in Australia for specific patient groups under strict medical supervision. Other than in these limited circumstances, the cultivation, possession and supply of cannabis remains prohibited in Australia (DoH 2017a).

Prohibited substances

The possession and supply of other illicit drugs such as cannabis, meth/amphetamine, heroin and cocaine are prohibited in Australia. Illicit drugs are commonly sourced for use from friends and relatives, dealers and online (AIHW 2020). Research with people who use drugs suggest illicit drugs are readily available in Australia.

The majority of people who inject drugs that were surveyed as part of the 2019 Illicit Drug Reporting System (IDRS) interviews indicated that heroin, meth/amphetamine, cannabis and cocaine were either ‘easy’ or ‘very easy’ to obtain (Peacock et al. 2019b). However, 16% of people found methamphetamine powder ‘difficult’ to obtain, a significant increase from 2018 (9%) (Peacock et al. 2019b).

Box HARM1: Data sources of regular drug consumers

The National Drug and Alcohol Research Centre (NDARC) Drug Trends program monitors trends in drugs across Australia. Information is collected from a range of sources including annual interviews with people across Australia who regularly inject drugs through the Illicit Drug Reporting System (IDRS) and those who regularly use ecstasy or other stimulants through the Ecstasy and Related Drugs Reporting System (EDRS). The IDRS and EDRS sample is a sentinel group that provides information on patterns of drug use and market trends.

The IDRS primarily consists of interviews with people who regularly inject drugs, conducted in the capital cities of Australia. The IDRS also includes data from interviews with key experts and other professionals who regularly work with illicit drug users and other indicator data related to illicit drugs (Peacock et al. 2019b).

The EDRS uses a similar methodology to the IDRS in that it monitors the price, purity and availability of ‘ecstasy’ and other drugs such as methamphetamine, cocaine, gamma-hydroxybutyrate (GHB), d-lysergic acid (LSD), 3,4-methylendioxyamphetamine (MDA) and ketamine. It also examines trends in the use and harms of these drugs (Peacock et al. 2019a).

It is important to note that the results from the IDRS and EDRS surveys are not representative of consumers and drug use in the general population, The aim of these data are intended to provide evidence that is indicative of emerging issues that warrant further monitoring.

Further information about the Drug Trends program.

There have been fluctuations in the illicit drug market at certain times. For example, in the early 2000s there was a widespread heroin shortage in Australia, which followed a period of unprecedented heroin availability in Australia in the late 1990s. The heroin shortage has been attributed to a range of factors, including high purity and low profit margins for dealers, along with a number of law enforcement seizures (Degenhardt, Day & Hall 2004).

Examples of supply reduction initiatives to limit the availability of illicit drugs include:

  • law enforcement operations involving drug seizures and arrests;
  • disrupting the diversion of precursor chemicals that are used in the manufacture of illicit drugs.

Drug seizures

The ACIC collects national illicit drug seizure data annually from federal, state and territory police services, including the number and weight of seizures to inform the Illicit Drug Data Report (IDDR). According to the 2017–18 IDDR, there were 112,827 national illicit drug seizures in 2017–18, which is equivalent to around one seizure every 5 minutes. While the number of national illicit drug seizures decreased slightly from 113,533 in 2016–17), there has been an overall increase of 67.0% over the last decade (from 67,559 in 2008–09) (Figure HARM3). Cannabis (52.4%) and amphetamine-type stimulants (ATS; 32.9%) accounted for the greatest proportion of national illicit drug seizures in 2017–18. The number of cannabis seizures decreased in 2017–18 and ATS seizures remained relatively stable (ACIC 2019a).

The weight of illicit drugs seized nationally was a record 30.6 tonnes in 2017–18, an increase of 130.0% over the last decade (from 13.3 tonnes in 2008–09) (ACIC 2019a). This, in part, is driven by an increase in the weight of cocaine seized, which increased 173% from 721 kilograms in 2015–16 to 1,970kg in 2017–18 (the second highest weight recorded for cocaine, following a record 4,623 kilograms in 2016–17). The weight of ATS seized in 2017–18 (11,205 kilograms) was the second highest recorded and represented an increase of 48% from the 7,571 kilograms seized in 2016-17. ATS accounted for the greatest proportion of the weight of illicit drugs seized in 2017–18 (36.6%) followed by cannabis (28.3%), illicit drugs classified as other and unknown (27.4%), cocaine (6.4%) and heroin and other opioids (1.2%) (Figure HARM3).

Figure HARM3 - a data visualisation showing number and weight of national illicit drug seizures, 2008-09 to 2017-18.

Visualisation not available for printing

Wastewater analysis

Wastewater analysis provides estimates of drug usage in a population by measuring concentrations of drug metabolites (excreted into the sewer system after consumption) in wastewater samples. The National Wastewater Drug Monitoring Program (NWDMP) of the Australian Criminal Intelligence Commission (ACIC) monitors selected substances of concern in the most populated regions of Australia (ACIC 2020).

Fifty-three wastewater treatment sites participated nationally in the December 2019 collection (18 sites were located in capital cities and 35 in regional locations) covering 43% of the Australian population, which equates to about 10 million people. Of the substances monitored by the NWDMP that have available dose data, alcohol and nicotine remain the highest consumed substances and methylamphetamine continues to be the most consumed illicit drug (ACIC 2020).

Box HARM2: Differences between self-reported illicit drug consumption data and wastewater analysis data

Results from the National Wastewater Drug Monitoring Program (NWDMP) indicate that methylamphetamine is the highest consumed illicit drug in Australia, for substances monitored by the program that have available dose data. This analysis excludes cannabis, the drug found to have the highest self-reported level of recent consumption (11.6%) in the 2019 National Drug Strategy Household Survey (NDSHS). The NDSHS results also indicate higher proportions of recent use for cocaine (4.2%) and ecstasy (3.0%) than for meth/amphetamine (1.3%) (Table S2.32).

It is important to note the different methodologies and sample coverage for the collections. The NWDMP measures the level of consumption of the specified substances within the community. The NDSHS findings are based on self-reported survey data from people aged 14 and over who live in residential dwellings; this excludes people living in non-private dwellings, institutions (such as prisons and drug and alcohol rehabilitation centres) and people experiencing homelessness. Results are not verified by blood tests or other screening measures and estimates of illicit drug use in the NDSHS are likely to be underestimates of actual use. In addition, some non-response bias is expected, but this bias has not been measured.

Differences in the frequency of consumption of different drugs may account, in part, for the higher level of methylamphetamine consumption reported in the NWDMP. The NDSHS results indicate that a higher proportion of people who recently used meth/amphetamine (16.9%) reported using it at least once a week or more, and this increased to 29% among those who used crystal/ice as their main form of meth/amphetamines. In comparison, 6.7% of people who used ecstasy and 4.5% of people who used cocaine reported using them at least once a week or more (AIHW 2020).

For further information, see:

The ACIC has assessed the relationship between supply and demand in the Australian methylamphetamine market by overlaying data from the NWDMP with illicit drug seizure data. The key findings indicate that large seizures have an impact on consumption, particularly in capital cities. The impact is not immediate and usually lasts between 2 to 4 months (ACIC 2019b).


ACIC (Australian Criminal Intelligence Commission) 2019a. Illicit Drug Data Report 2017-18. Canberra: ACIC. Viewed 7 August 2019.

ACIC 2019b. Methylamphetamine supply reduction—measures of effectiveness. Canberra: ACIC. Viewed 14 October 2019.

ACIC 2020. National Wastewater Drug Monitoring Program Report 10, 2020. Canberra: ACIC. Viewed 30 June 2020.

AIHW (Australian Institute of Health and Welfare) 2020. National Drug Strategy Household Survey 2019. Drug statistics series no. 32. Cat. no. PHE 270.Canberra: AIHW. Viewed 16 July 2020.

Degenhardt L, Day C & Hall W 2004. The causes, course and consequences of the heroin shortage in Australia. Canberra: National Drug Law Enforcement Research Fund.

DoH (Department of Health) 2017a. Medicinal cannabis. Canberra: Office of Drug Control. Viewed 4 January 2018.

DoH 2017b. National Drug Strategy 2017–2026. Canberra: Australian Government. Viewed 12 January 2018.

Peacock A, Karlsson A, Uporova J, Gibbs D,  Swanton R, Kelly G, Price O, Bruno R, Dietze P, Lenton S, Salom C,  Degenhardt L & Farrell M 2019a. Australian Drug Trends 2019. Key findings from the National Ecstasy and Related Drugs Reporting System (EDRS) Interviews. Sydney, National Drug and Alcohol Research Centre, UNSW Australia.

Peacock A, Uporova J, Karlsson A, Gibbs D, Swanton R, Kelly G, Price O, Bruno R, Dietze P, Lenton S, Salom C, Degenhardt L & Farrell M 2019b. Australian Drug Trends 2019: Key findings from the National Illicit Drug Reporting System Interviews. Sydney, National Drug and Alcohol Research Centre, UNSW Australia.

TGA (Therapeutic Goods Administration) 2018. Regulation basics. Viewed 2 February 2018.