Changes to drug markets can affect drug use and related harms. We aimed to describe market trends of heroin, methamphetamine, cocaine and ecstasy in Australia following the introduction of COVID-19 pandemic-associated restrictions.

Australians residing in capital cities who regularly inject drugs (n ∼= 900 each year) or regularly use ecstasy and/or other illicit stimulants (n ∼= 800 each year) participated in annual interviews 2014-2022. We used self-reported market indicators (price, availability, and purity) for heroin, crystal methamphetamine, cocaine, and ecstasy crystal to estimate generalised additive models. Observations from the 2014-2019 surveys were used to establish the pre-pandemic trend; 2020, 2021 and 2022 observations were considered immediate, short-term and longer-term changes since the introduction of pandemic restrictions.

Immediate impacts on market indicators were observed for heroin and methamphetamine in 2020 relative to the 2014-2019 trend; price per cap/point increased (β: A$9.69, 95% confidence interval [CI]: 2.25-17.1 and β: A$40.3, 95% CI: 33.1-47.5, respectively), while perceived availability (adjusted odds ratio [aOR] for 'easy'/'very easy' to obtain: 0.38, 95% CI: 0.24-0.59 and aOR: 0.08, 95% CI: 0.03-0.25, respectively) and perceived purity (aOR for 'high' purity: 0.36, 95% CI: 0.23-0.54 and aOR: 0.33, 95% CI: 0.20-0.54, respectively) decreased. There was no longer evidence for change in 2021 or 2022 relative to the 2014-2019 trend. Changes to ecstasy and cocaine markets were most evident in 2022 relative to the pre-pandemic trend: price per gram increased (β: A$92.8, 95% CI: 61.6-124 and β: A$24.3, 95% CI: 7.93-40.6, respectively) and perceived purity decreased (aOR for 'high purity': 0.18, 95% CI: 0.09-0.35 and 0.57, 95% CI: 0.36-0.90, respectively), while ecstasy was also perceived as less easy to obtain (aOR: 0.18, 95% CI: 0.09-0.35).

There were distinct disruptions to illicit drug markets in Australia after the COVID-19 pandemic began; the timing and magnitude varied by drug.