Extra-high cannabis theory goes up in smoke explains how marijuana is no more potent than it used to be:
The US drugs ‘tsar’ John Walters and toxicologist John Henry of St Mary’s hospital in Paddington, west London, are among those who have warned that the cannabis available now bears little resemblance to that on the market 30 years ago, with serious health dangers for regular users.The EU study says that the strength of the active ingredient – THC – has remained unchanged at about 6% for most of the cannabis smoked in Britain. It says the amount of cannabis put in the typical British joint has also remained constant for 20 years at about 200mg for marijuana and 150mg for resin.
The results are based on analysis by the Forensic Science Service of cannabis seized by the police between 1995 and 2002.