Published by Wiley- Here is the abstract
There appears to be general agreement that synthetic drugs could come to dominate the drug trade, with important implications for policy. Policymakers and researchers should consider how an ongoing shift to synthetic drugs may demand new ideas. Innovations in drug supply require innovation in drug policy and programs.
Our article  generated valuable comments, but little debate. There appears to be general agreement that synthetic drugs could come to dominate the drug trade, with important implications for drug policy.
Griffiths et al.  note parallels between our observations concerning illegally produced fentanyls in North America and the growing prevalence in Europe of synthetic drugs that act similarly to cannabis, cocaine, ecstasy or heroin. Griffiths et al. challenge us to think of the fentanyl explosion—horrible as it is—as just one prominent case of a more general pattern.
We embrace that proposition, and suggest thinking about the spread of novel synthetic psychoactive substances as instances of innovation in production technology. Advances in chemistry, communication and transportation will continue to impact drug markets, drug use and drug‐related problems. A key insight is that revolutions often happen incrementally—but inexorably.
Historical analogies of other revolutionary changes in product technology may be instructive. Consider, for example, how synthetic fibers overtook natural fibers for clothing in the 20th century. Synthetic alternatives are cheaper to produce, more durable and capable of high performance, making them attractive to the fashion and apparel industries. This did not happen overnight, but the writing was on the wall by mid‐century, at least for those who paid attention to the signs (c.f. Farago, 1950 ). Some natural fibers remain popular, but they serve a much‐diminished role; the same might happen in the long term for some plant‐based drugs, with cheaper and easier‐to‐traffic synthetic alternatives eclipsing heroin and maybe even cocaine. Perhaps cocaine and heroin will become status goods, counterpart in their markets to cashmere and merino wool for sweaters.
A shift towards synthetic drugs presents multiple policy challenges. First and foremost, this outward shift in the supply curve is likely to challenge standard rationales for supply reduction interventions. Traditionally, constraining supply was expected to reduce availability and raise prices, thereby reducing consumption. Law enforcement has had limited success at raising prices in the past  and may fare even less well against synthetics that can be cheaply produced anywhere. This may necessitate a reorientation of supply‐side policies, prioritizing market surveillance and investigating specific suppliers who create unusual harm, e.g. by concealing synthetics as diverted medications or other drugs, instead of striving to arrest large numbers of dealers or eradicate illicit crops altogether.
Expanded supply puts a premium on demand reduction, but also—as Bohnert & Lin  note—creates challenges. Synthetics may challenge existing treatment responses given their novelty or pharmacology which, coupled with retail price declines brought on by inexpensive substitutes, may result in higher consumption of some drugs. Thus, greater efforts are needed to re‐think prevention messaging, expand high‐quality treatment and find new interventions for novel drugs.
However, innovating demand‐reduction interventions takes time and may not address directly the harm to individuals exposed to synthetics sold as something else. May et al.  note that an effective response now may require fundamental changes to drug policy.
There is no reason to think that doing more of the same will stop the spread of synthetics . Therefore, policymakers and researchers should consider how an ongoing shift to synthetic drugs may demand new ideas. We must respond to innovation in drug supply with innovation in drug policy and programs.