Australian Street Cannabis Averaged 12% THC With Almost No CBD, and Users Could Not Gauge Potency | Research

The takeaway

Testing of 127 street cannabis samples in regional Australia found an average of 12% THC with negligible CBD, and users' perception of strength did not correlate with actual THC content.

Cannabis consumers in unregulated markets and policymakers considering cannabis regulation.

Users' perceived strength showed zero correlation with actual THC content

What the researchers found

One gram of Australian street cannabis contained an average of 34.8 mg THC (about 7 standard THC units) and 12% total THC with only 0.3% total CBD. THC concentrations were stable across participants' samples over time. Critically, users' subjective assessments of cannabis strength showed no correlation with the actual THC content of their products.

Why it matters

In unregulated markets, consumers have no reliable way to know what they are consuming. The finding that perceived strength does not match actual THC content means users cannot self-regulate their dosing based on experience alone.

The numbers in context

37 participants, 127 samples. Average per gram: 34.8 mg THC (6.96 standard THC units), 12% total THC, 0.3% total CBD. THC stable across timepoints (p>0.05). No correlation between perceived strength and actual THC content (p>0.05).

How the study worked

Participants donated two 1-gram cannabis samples at three timepoints approximately 9 weeks apart (6 samples total) over 5 months. High-performance liquid chromatography quantified concentrations of THC, CBD, and five other cannabinoids plus their acid precursors in 127 total samples from 37 participants.

What this study cannot tell us

Convenience sample from one regional area of Australia. 37 participants may not represent all cannabis users. Street cannabis composition varies by region and source. Self-reported strength perception is subjective.

How to read the evidence

Moderate: objective chemical analysis with repeated sampling over time, though limited by small regional convenience sample.

When this study was published

2025 study.

The bigger picture

This is the first comprehensive analysis of Australian street cannabis potency in over a decade. The high THC-to-CBD ratio mirrors international trends toward high-potency, CBD-depleted cannabis, which has been linked to greater mental health risks.

Questions still open

Has Australian street cannabis potency increased since the last assessment over a decade ago? Would labeling requirements in regulated markets help consumers make safer choices? Does the near-absence of CBD in street cannabis increase health risks?

Common questions

Can you tell how strong cannabis is by using it?

This study suggests not. Users' subjective assessment of strength had no correlation with the measured THC content, meaning experience alone is not a reliable guide to potency.

Is street cannabis getting stronger in Australia?

At 12% average THC, levels appear to have increased compared to reports from over a decade ago, though they are lower than some international averages. CBD levels remain very low.

Read the original research

Cannabis in the wild: Analysis of street cannabis and cannabinoid composition in Australia.

The International journal on drug policy, 145, 104974

View on PubMed ↗Publisher’s paper ↗

Citation

Lorenzetti, Valentina; Goodwin, Isabella; Christensen, Erynn; Kirkham, Rebecca; Chye, Yann; Galettis, Peter; Gordon, Rebecca; Solowij, Nadia; Yücel, Murat. (2025). Cannabis in the wild: Analysis of street cannabis and cannabinoid composition in Australia.. The International journal on drug policy, 145, 104974. https://doi.org/10.1016/j.drugpo.2025.104974