For more than a decade, the United Kingdom has waged an increasingly desperate battle against novel psychoactive substances—the synthetic compounds designed specifically to evade drug laws while mimicking the effects of controlled substances like heroin, cocaine, and cannabis. The government has banned individual chemicals, criminalized entire families of compounds, and passed sweeping legislation that made any psychoactive substance illegal unless specifically exempted.

None of it worked particularly well. What did work, according to a comprehensive new study published in Frontiers in Pharmacology, was something Britain had no control over: legislation passed thousands of miles away in China.

The research, conducted by scientists at King’s College London using 15 years of mortality data from England, Wales, and Northern Ireland, represents the first systematic evaluation of how drug controls in different countries actually affect deaths on the ground. The findings carry profound implications for how nations approach drug policy in a globalized world.

According to the authors of the study, “Controls implemented in the producing countries were associated with larger reductions in NPS detections in deaths than controls introduced solely within the consuming country.”

The study examined post-mortem toxicology reports from 2007 to 2022, tracking the presence of novel psychoactive substances across three major drug classes: opioids, stimulants, and cannabinoids. The researchers then mapped these detections against the timing of legislative controls in the UK, China, and through United Nations conventions.

The pattern that emerged was stark. While Britain typically enacted controls first, often years before other jurisdictions, these domestic measures had limited effect on whether the substances continued appearing in British deaths. By contrast, when China—recognized globally as a primary source of NPS manufacturing—banned the same compounds, detections in UK fatalities dropped substantially.

The most dramatic example came from synthetic cannabinoids, the class of drugs sold under names like “Spice” that have plagued British prisons and homeless populations. In 2021, China implemented a generic ban covering entire structural families of these compounds. Within a year, detections in UK deaths plummeted from over 100 to just 14.

“The illicit drug trade is international, and different countries have developed different strategies intended to minimize its negative effects,” the study authors wrote in an accompanying editorial. “But which approaches to banning substances are actually most effective in reducing harm?”

Their answer upends conventional thinking about drug enforcement. The research suggests that as long as chemicals can be manufactured legally in one country and shipped internationally through internet trading and rapid postal services, consumer nations are fighting with one hand tied behind their back.

This dynamic has created what researchers have long described as a “whack-a-mole” game between regulators and manufacturers. When one substance gets banned, producers quickly design chemical variants that fall outside the specific wording of the law. The cycle has repeated endlessly, with each generation of controls spawning a new generation of drugs.

The UN system for controlling substances, while providing global coordination, moves slowly by design. Recommendations must pass through the World Health Organization’s Expert Committee on Drug Dependence before reaching the Commission on Narcotic Drugs. Member states then incorporate these decisions into national law. The process can take years—time during which new substances proliferate.

According to the authors, “National legislation and enforcement alone cannot eliminate drug use or its associated harms. For this reason, they must be complemented by wide-ranging harm-reduction strategies.”

Britain has tried various approaches to accelerate domestic responses. The Misuse of Drugs Act of 1971 was supplemented by Temporary Class Drug Orders in 2011, allowing emergency controls while evidence of harm was gathered. Then came the Psychoactive Substances Act of 2016, which took a blanket approach by making any psychoactive substance illegal unless specifically exempted. This effectively shuttered “head shops” and UK-based online vendors.

Yet novel psychoactive substances remained accessible through international internet trading and established drug distribution networks. The supply simply shifted underground while continuing to flow from overseas manufacturers.

The study did find one area where classical substances—those under international control before 2007—dominated throughout the research period. Heroin, cocaine, and cannabis remained the primary drivers of drug-related mortality. Deaths involving cocaine, for instance, rose from representing 59 percent of stimulant detections in 2014 to more than 86 percent by 2022.

This points to another troubling finding: banning novel substances may simply push users back toward more dangerous alternatives. The researchers cite what economists call the “potency paradox”—restrictions on one substance can unintentionally steer users toward more potent options. When ketamine was controlled in Britain, the market responded with methoxetamine and diphenidines, compounds with greater potency and longer duration of action that produced more severe toxicological outcomes.

A similar dynamic is now playing out with opioids. The study period captured the beginning of what has become Britain’s nitazene crisis. These ultra-potent synthetic opioids began appearing after controls restricted fentanyl analogues and reduced heroin availability from Afghanistan. Both the UK and China implemented generic controls on nitazenes in 2025, but the researchers note it is too early to assess their impact.

The authors state, “If, as a result of Chinese legislative actions, production of NPS for the illicit drug trade becomes more geographically diverse, action to identify new sources of production and to encourage and support supplier nations to restrict production as soon as practicable will be required.”

The study carries limitations that the authors acknowledge. Coronial reporting to the National Programme on Substance Use Mortality is voluntary, meaning not all deaths were captured. Toxicology screens for novel substances were not requested in every case and varied between laboratories. In earlier years, when awareness of these drugs was lower, they may have gone undetected entirely.

Still, the implications for policy are substantial. The research suggests that Britain’s domestic drug landscape is being shaped largely by the pace and scope of independent international legislation—a position the authors describe as “vulnerable.”

The path forward, they argue, requires multiple strategies working in concert: early domestic action to enable law enforcement, international cooperation to restrict production at the source, and robust harm reduction measures to address the reality that demand for psychoactive substances persists regardless of legal status.

The authors conclude, “Reducing drug harms will therefore require not only responsive legislation and international co-operation, but also investment in education, prevention, and treatment to address the drivers of demand.”

Without this combined approach, the researchers warn, the cycle of novel substance emergence, prohibition, and displacement will continue to undermine public health. The whack-a-mole game will go on—with China, rather than Britain, holding the mallet.

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ENDNOTES

1. Rock KL, Treble R, and Copeland CS. “Legislating novel psychoactive substances: lessons from 15 years of UK mortality data (2007-2022).” Frontiers in Pharmacology. Published 29 January 2026. DOI: 10.3389/fphar.2025.1708335
2. “Reducing drug deaths from novel psychoactive substances relies on foreign legislation, but here’s how it can be tackled closer to home.” EurekAlert! 29 January 2026. https://www.eurekalert.org/news-releases/1113837
3. United Nations Office on Drugs and Crime. Single Convention on Narcotic Drugs (1961); Convention on Psychotropic Substances (1971); Convention against Illicit Traffic in Narcotic Drugs and Psychotropic Substances (1988).
4. UK Government. Misuse of Drugs Act 1971.
5. UK Government. Psychoactive Substances Act 2016.
6. Ministry of Public Security of the People’s Republic of China. Announcements on controlled substances (2015, 2018, 2019, 2021, 2025).
7. Holland A, et al. “Nitazenes—heralding a second wave for the UK drug-related death crisis?” The Lancet Public Health. 2024;9(2):e71-e72.
8. Deen AA, et al. “Deaths from novel psychoactive substances in England, Wales and Northern Ireland: evaluating the impact of the UK Psychoactive Substances Act 2016.” Journal of Psychopharmacology. 2021;35(11):1315-1323.
9. Chiappini S, et al. “Methoxetamine-related deaths in the UK: an overview.” Human Psychopharmacology. 2015;30(4):244-248.
10. Zhao M. “The illicit supply of new psychoactive substances within and from China: a descriptive analysis.” International Journal of Offender Therapy and Comparative Criminology. 2022;66(5):495-516.