Half of Low-THC Cannabis Products in Switzerland Were Laced with Synthetic Cannabinoids | Research

The takeaway

Drug checking services found 50% of low-THC cannabis samples submitted in Switzerland were adulterated with synthetic cannabinoids, with users of adulterated products reporting significantly more adverse effects.

Cannabis consumers, harm reduction workers, drug policy regulators

50% of low-THC samples contained synthetic cannabinoids

What the researchers found

Of 94 samples, 50% contained up to three different synthetic cannabinoids, with MDMB-4en-PINACA most common. All adulterated flowers had 1% or less THC. The synthetic cannabinoid group had significantly more adverse events (P=0.041), with worse psychological (P=0.0007) and cardiological (P=0.020) outcomes compared to the THC-only group.

Why it matters

Legal low-THC cannabis products are being used as carrier materials for dangerous synthetic cannabinoids. Users think they are consuming a mild product but are unknowingly exposed to highly potent substances.

The numbers in context

94 samples; 50% adulterated; up to 3 SCs per sample; MDMB-4en-PINACA most common; all adulterated flowers had ≤1% THC; more psychological (P=0.0007) and cardiac (P=0.020) adverse effects

How the study worked

Analysis of cannabis samples submitted to three Swiss drug checking services from January 2020 to July 2021. LC-HRMS for synthetic cannabinoid screening and semi-quantification; GC-FID for THC/CBD quantification. User self-reports of adverse effects collected.

What this study cannot tell us

Samples submitted to drug checking services may not represent the broader market. Adverse effect reporting was voluntary and self-reported.

How to read the evidence

Systematic drug checking with validated analytical methods and user-reported outcomes, though samples are self-selected.

When this study was published

Published in 2022

The bigger picture

This represents a new public health threat: legal low-THC cannabis products being weaponized as vehicles for synthetic cannabinoids. Drug checking services proved essential for detecting this trend.

Questions still open

Is this adulteration trend spreading beyond Switzerland? Would mandatory testing of legal low-THC products prevent this contamination?

Common questions

Can legal low-THC cannabis contain dangerous additives?

This Swiss study found 50% of low-THC cannabis samples were adulterated with synthetic cannabinoids, with some containing up to three different synthetic compounds. Users cannot detect these by appearance or smell.

What happens when you unknowingly consume synthetic cannabinoids?

Users of adulterated products reported significantly more adverse effects, particularly psychological problems (P=0.0007) and cardiac symptoms (P=0.020) compared to those who consumed genuine low-THC cannabis.

Read the original research

Adulteration of low-delta-9-tetrahydrocannabinol products with synthetic cannabinoids: Results from drug checking services.

Drug testing and analysis, 14(6), 1026-1039

View on PubMed ↗Publisher’s paper ↗

Citation

Monti, Manuela Carla; Zeugin, Jill; Koch, Konrad; Milenkovic, Natasa; Scheurer, Eva; Mercer-Chalmers-Bender, Katja. (2022). Adulteration of low-delta-9-tetrahydrocannabinol products with synthetic cannabinoids: Results from drug checking services.. Drug testing and analysis, 14(6), 1026-1039. https://doi.org/10.1002/dta.3220