Dutch research showed that THC (the active substance in cannabis) in the Dutch cannabis dropped from 17,5% in 2006, to 16% in 2007. The THC contents of the ‘import hash’ dropped in the same time span from 18,7% to 13,3%. The average price however has gone up 20% compared to 2006. These are results of the yearly THC research the Dutch Trimbos-institute does for the ministry of public health.
Since 1999 the Trimbos-institute of Mental Health and Addiction is assigned to do research on the strength of cannabis ‘products’ sold in the Dutch Coffeeshops. Until 2004 there was an increase of THC contents in Dutch cannabis. Recent results show that from 2004 till end 2007 the THC contents dropped from more than 20% to only 16%
