"The number of opioid NPS found on markets worldwide grew from just one substance in 2009 to 14 in 2015, 56 in 2019 and 87 in 2020,20 by which time synthetic opioids had become the third most numerous group of NPS in terms of the number of different substances reported by Member States in 2020 (after NPS stimulants and NPS cannabinoid receptor agonists and slightly ahead of NPS hallucinogens).21 Synthetic opioids accounted for the highest number of NPS identified for the first time at global level in 2020, with 22 new substances (29 per cent of those identified), including both fentanyl analogues and other opioids. Although fentanyl has been under international control since 1964 and a number of fentanyl analogue medicaments were scheduled in the 1980s (sufentanil, alfentanil and 3-methylfentanyl) and in the 1990s (thiofentanyl and remifentanil), a far larger number of fentanyl-type NPS (i.e. fentanyl analogues without any recognized medical use) emerged in the 2010s.22

"The number of NPS categorized as “other substances” has also continued to grow. "Other substances" include synthetic NPS that do not belong to a precise category, in particular NPS with sedative and hypnotic effects, most of which are benzodiazepine-type NPS.23 Benzodiazepine-type NPS are often sold at very low prices, sometimes in packages mimicking existing medicines, have varying dosages of active ingredients and contain contaminants, including highly potent synthetic opioids.24


UNODC, World Drug Report 2022 (United Nations publication, 2022).