"The internet has facilitated the sale of licit and illicit drugs for more than 15 years,10 11 12 13 but when the first cryptomarket, Silk Road 1, came online in 2011, illicit drugs began to be traded in large quantities. The annual turnover of drug sales conducted through cryptomarkets is estimated to be in the hundreds of millions of dollars,14 with most transactions involving recreational drugs (eg, cannabis, “ecstasy”). Before 2014, prescription drugs represented slightly less than 10% of all cryptomarket sales.14 15 People who buy through cryptomarkets are believed to be predominantly male, young (<25 years), educated, employed, and white.16 17 18 19 20 21

"Since 2011, cryptomarkets have been analysed through the digital traces they leave online,22 using automated software “crawlers” that collect publicly available data hosted on websites. The wealth of data available to researchers employing digital trace analysis includes the aliases and purported country level locations of drug vendors and the countries to which they are willing to make shipments. From each product listing posted by vendors on the marketplace, the drug type, price, and quantity can be determined, alongside customer feedback. Using these data, researchers have been able to track the growth of drug trading through the darknet,14 15 determining overall size, composition, and geographical distribution.20 23 24 25 Feedback posted by customers are used by researchers as a proxy for estimating numbers of transactions and revenues generated by drug vendors."


Martin J, Cunliffe J, Décary-Hétu D, Aldridge J. Effect of restricting the legal supply of prescription opioids on buying through online illicit marketplaces: interrupted time series analysis. The BMJ. 2018;361:k2270. doi:10.1136/bmj.k2270.