The added value of drug checking data in combination with data from online drug monitoring to evaluate NPS market dynamics: the case of 3-MMC in the Netherlands.

Every year a vast number of new psychoactive substances (NPS) appears for the first time in Europe. In most cases these substances are being introduced as substitutes for NPS that have recently been subjected to (inter)national control measures. To assess the potential risks these substance may pose it is fundamental to monitor NPS market dynamics and responses to legislative changes using a variety of sources. In the Netherlands, a comprehensive set of monitoring tools exist which allow the study of market dynamics: in this case focusing on 3-MMC, before and after legislative measures were taken.

Drug-checking results from the Drugs Information and Monitoring System (DIMS) were compared with data from Dutch online dicussion boards. Data was collected in 2021, before and after 3-MMC was prohibited on October 28, 2021. In 2021, both the number of drug samples sold as 3-MMC submitted to DIMS, as well as the number of topics discussing 3-MMC on Dutch online discussion boards increased compared to previous years. Chemical analysis showed that throughout 2021 nearly all samples submitted as 3-MMC did contain 3-MMC. In contrast, nearly half of the samples submitted as 4-MMC, which has been a controlled substance in the Netherlands since 2012, contained 3-MMC instead. Although vendors started offering 3-CMC as a legal substitute for 3-MMC, this did not yet lead to an increase in either the number of samples submitted to DIMS or the number of topics on Dutch online discussion boards. Research will continue to determine the long-term effects of the recent legislative changes on the market dynamics around 3-MMC. The case of 3-MMC in the Netherlands shows the added value of drug checking in combination with data from online drug monitoring to obtain a more detailed understanding of the consequences of legislative measures to control NPS.