"Alongside their legitimate uses as medicines and in research, the fentanils also have a long history of illicit use as replacements for heroin and other controlled opioids. Between 1979 and 1988, more than 10 fentanils that had been made in illicit laboratories were detected on the drug market in the United States (Henderson, 1991). The first was alpha-methylfentanyl, followed by substances such as 3-methylfentanyl and 4-fluorofentanyl. Typically, they were sold as heroin or ‘synthetic heroin’. Together, these substances were involved in more than 100 deaths, mostly in the state of California. Later, in the mid-2000s, illicitly manufactured fentanyl was sold as heroin or in mixtures with heroin, and was responsible for outbreaks of overdoses that involved hundreds of deaths in the eastern United States (Schumann et al., 2008). It appears that, with the exception of Estonia, where 3-methylfentanyl and fentanyl were responsible for an epidemic of fatal poisonings during this time, these substances caused limited problems elsewhere in Europe (Berens et al., 1996; de Boer et al., 2003; Fritschi and Klein, 1995; Kronstrand et al., 1997; Ojanperä et al., 2008; Poortman-van der Meer and Huizer, 1996).

"Over the past few years, there has been a large increase in the availability of fentanils in the United States, Canada and Europe (Gladden et al., 2016; US CDC, 2015). This has been driven by the opioid epidemics in North America, interest in selling these substances in Europe and broader changes in the illicit drug market."

Source

European Monitoring Centre for Drugs and Drug Addiction (2018), Fentanils and synthetic cannabinoids: driving greater complexity into the drug situation. An update from the EU Early Warning System (June 2018), Publications Office of the European Union, Luxembourg.