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’ [1].

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

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. The study focuses on 13 licit and illicit drugs, including nicotine from tobacco, ethanol from alcohol intake, pharmaceutical opioids with abuse potential, illicit substances such as methylamphetamine, MDMA and cocaine, as well as a number of new psychoactive substances (NPS) including mephedrone and methylone. The measurement of cannabis consumption was included for the first time in the August 2018 collection [2].

The NWDMP is the only data set that provides a measure of drug consumption with geographic coverage of over 50% of the population and estimates taken at regular intervals. One of the limitations of the NWDMP is that it cannot differentiate between the medical and non-medical use of pharmaceutical drugs such as oxycodone and fentanyl. As such, it is important that other data sources such as general population and sentinel surveys are also used to estimate the consumption of licit and illicit drugs. As a collective, these data inform our understanding of drug markets and how we can best respond to reduce supply, demand and harm.

Fifty-eight wastewater sites participated in the August 2018 collection (22 sites were located in capital cities and 36 in regional locations) covering 56 per cent of the Australian population, which equates to about 13 million people. The results show that of the substances monitored by the NWDMP that have available dose data, alcohol and nicotine remain the highest consumed drugs and methylamphetamine continues to be the most consumed illicit drug [2].

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 2016-17 IDDR, there was 113,533 national illicit drug seizures in 2016-17 which is equivalent to around one seizure every 5 minutes. While the number of national illicit drug seizures decreased 1.6% from 2015–16 (115,421), it has increased 85.2% over the last decade (61,290 in 2007-08) (Figure HARM6). Cannabis (52.9%) and amphetamine-type stimulants (ATS; 32.9%) accounted for the greatest proportion of national illicit drug seizures in 2016-17, with ATS accounting for an increasing proportion of seizures over time [3].

The weight of illicit drugs seizured nationally increased 129.6% over the last decade, from 11.9 tones in 2007–08 to a record 27.4 tonnes in 2016–17 [3]. This, in part, is driven by an increase in the weight of cocaine seized, which increased  540.6% from 721 kilograms in 2015–16 to a record 4,623 kilograms in 2016–17. Cannabis and ATS acounted for the greatest proportion of the weight of illicit drugs seized in 2016–17 (both 27.5%) followed by illicit drugs classified as other and unknown (27.2%), cocaine (16.8%) and heroin and other opioids (1.0%) (Figure HARM6).

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Legal substances

The consumption of alcohol and tobacco is legal in Australia. Almost one in two (46%) Australians aged 14 years and over approved of regular adult consumption of alcohol (46%) compared with 15.7% who approved of regular tobacco use [4]. 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 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 [5].

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 [6].

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 street markets, and online [4]. Research with people who use drugs suggest illicit drugs are readily available in Australia. That is, the majority of people who inject drugs that were surveyed as part of the 2018 Illicit Drug Reporting System (IDRS) indicated that heroin, meth/amphetamine, cannabis and cocaine were either ‘easy’ or ‘very easy’ to obtain [7].

Box HARM1: Data sources of regular drug consumers

The National Drug and Alcohol Research Centre (NDARC) Drug trends program monitors trends in drug 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 a sentinel group of 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 [7].

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), dlysergic acid (LSD), 3,4-methylendioxyamphetamine (MDA) and ketamine. It also examines trends in the use and harms of these drugs [8].

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.

For information about Drug Trends program

That said, 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 [9]. 

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.


1. Department of Health 2017a. National Drug Strategy 2017-2026. Canberra: Australian Government. Viewed 12 January 2018.

2. Australian Criminal Intelligence Commission (ACIC) 2019. National wastewater drug monitoring program, report 6. Canberra: ACIC. Viewed 20 February 2019.

3. ACIC 2018. Illicit drug data report 2016-17. Canberra: ACIC. Viewed 20 September 2018.

4. Australian Institute of Health and Welfare (AIHW) 2017. National Drug Strategy Household Survey 2016: detailed findings. Drug statistics series no. 31. Cat. no. PHE 214. Canberra: AIHW. Viewed 14 December 2017.

5. Therapeutic Goods Administration (TGA) 2018. Regulation basics, accessed 2 February 2018.

6. Department of Health 2017b. Medicinal cannabis. Canberra: Office of Drug Control. Viewed 4 January 2018.

7. Peacock A, Gibbs D, Sutherland R, Uporova J, Karlsson A, Bruno R, Dietze P, Lenton S, Alati R, Degenhardt L & Farrell M 2018. Australian Drug Trends 2018: Key findings from the National Illicit Drug Reporting System Interviews. Sydney, National Drug and Alcohol Research Centre, UNSW Australia.

8. Peacock A, Gibbs D, Karlsson A, Uporova J, Sutherland R, Bruno R, Dietze P, Lenton S, Alati R, Degenhardt L & Farrell M 2018. Australian Drug Trends 2018. Key findings from the National Ecstasy and Related Drugs Reporting System (EDRS) Interviews. Sydney, National Drug and Alcohol Research Centre, UNSW Australia.

9. 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.