Cannabis resin now 25% more potent, global study reveals

Concentrations of intoxicating THC have risen, data from more than 80,000 street drug samples gathered over 50 years shows
The Observer (UK)
Sunday, November 15, 2020

hash cannabis leafCannabis resin – or “hash” – has increased in strength by nearly 25% over the past half century, a major international study has revealed. Researchers with the Addiction and Mental Health Group at the University of Bath analysed data from more than 80,000 cannabis street samples tested in the past 50 years in the US, UK, Netherlands, France, Denmark, Italy and New Zealand. The findings reveal concentrations of THC – the intoxicating component of cannabis responsible for giving users a “high” – have changed over time. In herbal cannabis, THC concentrations increased by 14% between 1970 and 2017. This was primarily due to a rising market share of stronger varieties, such as sinsemilla. Concentrations in cannabis resin increased by 24% between 1975 and 2017.