An evaluation of the quality of medicinal grade cannabis in the Netherlands

Since 2003 medicinal grade cannabis is provided in the Netherlands on prescription through pharmacies. Growing, processing and packaging of the plant material are performed according to pharmaceutical standards and are supervised by the official Office of Medicinal Cannabis (OMC). The quality is guaranteed through regular testing by certified laboratories. However, in the Netherlands a tolerated illicit cannabis market exists in the form of so-called ‘coffeeshops’, which offers a wide variety of cannabis to the general public as well as to medicinal users of cannabis. Since cannabis has been available in the pharmacies, many patients have started to compare the price and quality of OMC and coffeeshop cannabis. As a result, the public debate on the success and necessity of the OMC program has been based more on personal experiences, rather than scientific data. The general opinion of consumers is that OMC cannabis is more expensive, without any clear difference in the quality. This study was performed in order to show any differences in quality that might exist between the official and illicit sources of cannabis for medicinal use. Cannabis samples obtained from randomly selected coffeeshops were compared to medicinal grade cannabis obtained from the OMC in a variety of validated tests. Many coffeeshop samples were found to contain less weight than expected, and all were contaminated with bacteria and fungi. No obvious differences were found in either cannabinoidor water-content of the samples. The obtained results show that medicinal cannabis offered through the pharmacies is more reliable and safer for the health of medical users of cannabis.