Skip to content
General News, Medical Health Aged Care

More than 1/3 illicit drugs sold on the dark web contain unexpected substances

RMIT University 3 mins read

Testing of illicit drugs bought online found 35% were not what they said they were, highlighting the urgent need for more local drug testing facilities in Australia to prevent harm and overdose.  

The RMIT-led study analysed 103 illicit drug samples sourced from the now-defunct dark web forum Test4Pay in collaboration with the Australian National University, UNSW Sydney and Canadian testing facility Get Your Drugs Tested. 

While 65% of samples contained only the advertised substance, the study found 14% of samples had a mixture of the advertised substance with other psychoactive or potentially harmful chemicals.  

Meanwhile, 21% of samples did not contain any of the advertised substances.  

MDMA, methamphetamines and heroin sourced were consistently found to only contain the advertised substance.  

Products sold as ketamine, 2C-B and alprazolam were most likely to be completely substituted with other substances or new synthetic drugs, which increased the risk of unwanted side effects, potential overdose or death. 

Of the 19 cocaine samples tested, only four were pure cocaine while 13 contained other substances and two samples did not contain any cocaine at all.  

Lead researcher and RMIT Vice-Chancellor’s Senior Research Fellow, Dr Monica Barratt, said the results were concerning as drugs sold through cryptomarkets – online vendors on the dark web – were believed to be less likely to be mixed or substituted with other substances. 

“Cryptomarkets allow anonymous buyers to review purchases, which theoretically means vendors who sell inferior products are more likely to receive bad reviews, thereby rewarding vendors selling superior products,” said Barratt, from RMIT’s Social Equity Research Centre 

“But despite this perception of accountability and quality, our findings show prohibited drugs purchased from cryptomarkets are still not safe from adulteration and substitution.” 

The dark web drug market 

According to the 2023 National Ecstasy and Related Drugs Reporting System survey, there was a slight decline of people buying drugs on the dark web, with more people turning to messaging and social media apps to source drugs. 

“These apps are a lot more convenient and easier to use than the dark web, but they lack many of the security features and review capacities of darknet markets,” she said. 

Barratt said Australia’s policies on tackling darknet markets focused on using law enforcement to ‘disrupt’ operations. 

“These takedowns are used to create a sense of general deterrence through announcing arrests and interruptions to markets,” she said.  

“However, we know through research on darknet market takedown operations that this ecosystem is quick to adapt to removal of markets. 

“These days, vendors have accounts across many markets, in case one goes down, their clients can find them on other markets. This mitigates against the disruption of a takedown.”  

Australia’s approach to drug regulation 

With Australians finding new ways to source illicit drugs, Barratt said it was more urgent than ever to launch more drug checking services. 

Currently, CanTEST is the only drug checking service available in Australia, with Queensland due to launch its own services this year and Victoria considering following suit. 

“Drug checking is a precautionary and pragmatic response to the health risks of unpredictable drug markets, often detecting hazardous substances before they flood the local market,” she said. 

While drug checking services have been operating around the world for over 50 years, Barratt said Australia remained resistant to expanding the harm reduction service. 

“Australia’s resistance to opening more drug checking facilities stems from an assumption that drug checking ‘green lights’ drug use,” Barratt said.  

“Drug checking services never tell consumers that their drugs are ‘safe’ as no drug use can be 100% safe. 

“What the service can do is explain the known risks of specific drugs, in a credible and non judgemental way, enabling people who use drugs to adjust their behaviour to reduce risk.” 

A 2022 systemic review of pill testing found people who found unexpected substances in their drugs were more likely to discard them and adjust their use. 

“If we can prevent overdoses from happening in the first place, then we can not only reduce harm for consumers and avoid the pain felt by bereaved family members, but also ease the pressures on our emergency health system,” Barratt said.  

“Adulteration and substitution of drugs purchased in Australia from cryptomarkets: An analysis of Test4Pay” was published in the Drug and Alcohol Review (DOI: 10.1111/dar.13825) 

Monica J. Barratt, Matthew Ball, Gabriel T. W. Wong and Angus Quinton are co-authors. 


Contact details:

For interviews:  

Dr Monica Barratt: 0407 778 938 or [email protected] 

Please note Monica is unavailable for interviews between 9am-10am AEDT on Tuesday 5 March and all day Thursday 7 March. 

General enquiries: 0439 704 077 or [email protected] 

More from this category

  • Medical Health Aged Care
  • 15/03/2026
  • 05:15
Dementia Australia

Join us today for the Adelaide Memory Walk & Jog

What: Dementia Australia’s Adelaide Memory Walk & Jog   When: Sunday 15 March from 7:30am   Who: More than 1,000 locals participating on the day. People who have been impacted by dementia, their family, friends and carers.   Where: Wigley Reserve, Glenelg   Dementia Australia spokespeople and local residents are available for interview. Photos and video of previous Memory Walk & Jog events for publication are available for use. For more information visit: https://www.memorywalk.com.au/event/adelaide/home Dementia Australia is the source of trusted information, education and services for the estimated more than 446,500 Australians living with dementia, and the more than 1.7…

  • Contains:
  • General News
  • 14/03/2026
  • 07:00
NSW Office of Sport

Panthers and Office of Sport team up to address domestic violence in Central West

Panthers and Office of Sport team up to address domestic, family and sexual violence in the Central West Saturday, 14 March Editor’s note: images of the Panthers Foundation and Denison College of Secondary Education, Bathurst High Campus students are available here: https://officeofsport.intelligencebank.com/customshare/index/OEdny The NSW Office of Sport and Panthers Foundation, the official charity of the Penrith Panthers, have joined forces on a program aimed at reducing domestic, family and sexual violence in the Central West. The two-year partnership will see the Panthers Foundation deliver its Building Young Men and Empowering Young Women mentoring programs to teenagers throughout the region. Building…

  • Contains:
  • Medical Health Aged Care
  • 13/03/2026
  • 16:44
Dementia Australia

Last chance to join us for the Illawarra Memory Walk & Jog!

With only a few sleeps to go, walkers, joggers, runners and volunteers are getting ready for the 2026 Illawarra Memory Walk & Jog. More than 530 people have already signed-up - but there’s always room for more. Online registrations are still open, and participants are welcome to turn up and register on the day. Dementia Australia CEO Professor Tanya Buchanan said it was inspiring to see Illawarra locals unite to support Australians living with dementia, while also taking positive steps for their own brain health. “We are thrilled to be back in Illawarra on Sunday 22 March for the 2026…

  • Contains:

Media Outreach made fast, easy, simple.

Feature your press release on Medianet's News Hub every time you distribute with Medianet. Pay per release or save with a subscription.