Canberrans are among Australia's biggest users of pharmaceutical opioids like oxycodone and fentanyl, wastewater analysis has shown.
The analysis also revealed the ACT remained the second highest consumers of cocaine in the country, along with Queensland.
The figures were revealed in the latest report from National Criminal Intelligence Commission, released on Wednesday.
The commission tested one wastewater site in Canberra for drugs in August 2018, along with 52 other sites nationally for its National Wastewater Drug Monitoring Program.
It's the sixth report released by the commission, with the last analysis being performed in April 2018.
Tests in the ACT in August 2018 revealed the second highest average capital city consumption of heroin, as well as the pharmaceutical opioids fentanyl and oxycodone.
It showed in August for every 1000 people, about 10 doses of fentanyl were being taken each day, with about eight doses of oxycodone per 1000 people being taken each day.
The analysis also revealed that in August, about four doses of cocaine per 1000 people was being taken each day in Canberra.
This made Canberra one of the second highest consumers of cocaine in the country, with the report saying usage had been decreasing since late 2017.
Canberra's love affair with MDMA seemed to remain flat, reflecting the national average of about one or two doses per 1000 people each day.
This meant the summer of 2016 was well and truly over, when the commission's tests revealed that about seven doses of MDMA per 1000 people were then being taken in Canberra each day. Tests since have remained at one or two doses.
But ice, or methylamphetamine, remained Canberra's most popular drug, with about 22 doses per 1000 people being take each day in August 2018.
This was still well below the national capital city average of about 35 doses.
Heroin use was down, with Canberra only testing for about one or two doses per 1000 people each day
The last analysis in April 2018 showed about five doses per 1000 people were being taken in Canberra each day, a relatively stable trend since August 2017.
The commission's chief executive Michael Phelan said Australians appeared to have spent $9.6 billion on drugs in August 2018.
"This is money people could be spending on legitimate goods for themselves and their families,” Mr Phelan said.