Cannabis in the wild: Analysis of street cannabis and cannabinoid composition in Australia.
Valentina Lorenzetti, Isabella Goodwin, Erynn Christensen, Rebecca Kirkham, Yann Chye, Peter Galettis, Rebecca Gordon, Nadia Solowij, Murat Yücel
The International journal on drug policy November 2025 DOI: 10.1016/j.drugpo.2025.104974 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational study Peer reviewed |
|---|---|
| Sample size | 37 |
| Population | People who use illicit cannabis in regional Australia, donating street cannabis samples |
| Duration | Samples collected at 3 timepoints about 9 weeks apart over 5 months |
| Topics | Cannabis CBD |
| Keywords | Cannabinoids Toxicology |
| Key findings | Contemporary illicit street cannabis in regional Australia averaged 34.8 mg THC per gram (6.96 Standard THC units), 12.00% total THC and 0.30% total CBD, with THC concentrations stable over time. THC appears higher than in Australian samples collected over 10 years earlier but lower than international trends. Consumers' subjective ratings of cannabis strength did not correlate with measured THC content. |
Abstract
Australia has one of the highest rates of cannabis use globally, yet the concentration of Δ9-tetrahydrocannabinol (THC) of illicit street cannabis has not been formally assessed in over a decade. We aimed to comprehensively profile the concentration of THC, cannabidiol (CBD) and other cannabinoids in contemporary illicit street cannabis in regional Australia, assess variation over time, and examine how the amount of THC relates to consumer's perceived product strength. Participants donated two 1-gram samples of cannabis at 3 different timepoints (i.e., 6 samples total) ∼9-weeks apart, over 5 months. High-performance liquid chromatography quantified the concentrations of THC, CBD, cannabigerol, cannabichromene, cannabinol, tetrahydrocannabivarin, and their plant-based carboxylic acid precursors (THCA, CBDA, CBGA, CBNA, THCVA) in percentage and milligrams. Thirty-seven participants donated 127 cannabis samples. On average, one cannabis gram contained 34.8 mg THC (6.96 Standard THC units), 12.00 % total THC (THC+(THCA*0.877)), and 0.30 % total CBD (CBD+(CBDA*0.877)). THC concentrations remained stable across participants' current and past samples over time (p > 0.05). Finally, no correlation was found between participants' subjective assessments of cannabis strength and THC or total THC content in the same product (p > 0.05). Contemporary illicit street cannabis in regional Australia is high in THC and low in CBD. The concentration of THC is lower than international trends but appears to have increased compared to reports on illicit Australian cannabis collected over 10 years ago, while low concentrations of CBD have remained stable over time. Perceived cannabis strength may be influenced by factors beyond measurable THC concentrations, such as individual tolerance, consumption methods, or consumer expectations.
Comparable studies
Other observational and cohort studies on cannabis, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| High-potency cannabis and the risk of psychosis People with first episode of psychosis and healthy controls from the local population | 2009 | Case-control study | n = 454 |
| Ayahuasca-Assisted Therapy for Addiction: Results from a Preliminary Observational Study in Canada Rural aboriginal population | 2013 | Observational study | |
| Impaired cognitive performance in drug free users of recreational ecstasy (MDMA) Otherwise healthy young people | 2000 | Observational | |
| Continued cannabis use and risk of incidence and persistence of psychotic symptoms: 10 year follow-up cohort study Individuals from the general population in Germany aged 14-24 at baseline | 2011 | Observational cohort | n = 1,923 |
| Cannabis-induced psychosis and subsequent schizophrenia-spectrum disorders: follow-up study of 535 incident cases Patients treated for cannabis-induced psychotic symptoms in Denmark between 1994 and... | 2005 | Observational cohort | n = 535 |