"Descriptive analysis of the data collected through both the literature review and data scraping on the Dark Web indicated varying periods of volatility in the availability and distribution of psychoactive substances. Notably, no major changes were apparent in the distribution of substances, on average, between 2012 and 2019, as reported in the literature.

"Contrarily, the novel data collected in this study from 13 cryptomarkets between late 2022 and early 2023 showed that there was a relative change in the distribution of substances from data reported in 2012 to 2019. Specifically, the category of prescription drugs decreased in proportion, becoming the second smallest proportion of listings, from over 20% between 2012 and 2019 to under 5% between 2022 and 2023. In addition, opioid listings seemingly doubled, growing from 5.5% to 9.25%."

Source

Sudan HK, Tai AMY, Kim J, Krausz RM. Decrypting the cryptomarkets: Trends over a decade of the Dark Web drug trade. Drug Science, Policy and Law. 2023;9. doi:10.1177/20503245231215668.