Overview and History of W18 or W-18

A man on life support

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W-18 is a synthetic, opioid drug, also known as 4-chloro-N-[1-[2-(4-nitrophenyl)ethyl]-2-piperidinylidene]benzenesulfonamide). Synthetic opioid drugs are man-made copies of naturally occurring painkiller drugs, such as heroin, a drug that is made from certain strains of the poppy plant.

Opioid drugs are most often used in medical settings as powerful painkillers, although the euphoria that is part of the effect makes them attractive to drug dealers and drug users as recreational drugs. They are also typically highly addictive, producing tolerance quickly, and withdrawal if the person taking the drug for a period of time suddenly stops taking it.

Opioid drugs, whether natural or synthetic, also carry a significant risk of overdose, and for that reason are highly risky to take without medical supervision. The amount of the drug that can cause death varies a great deal from person to person, and small changes, such as how long and how much of the drug has been taken, recent weight loss, and interactions with other drugs taken, can drastically change the risk of overdose in the same person.

History of the W-18

In early 2016, W-18 hit the news in Calgary, Canada, when police seized the drug after it was implicated in a large number of drug-related deaths—over 200 people were thought to have lost their lives at least in part due to W-18. Yet the drug was developed many years earlier, in 1984, and was patented in Canada and the United States the same year, in anticipation of its potential use as a painkiller. However, its legitimate use has never been established.

It was not until 2013 when W-18 first seemed to have been discovered as a designer drug, where it was marketed by drug dealers as a legal substitute for other recreational drugs.

The approach of using drugs that have never been formally identified as illicit drugs is a way of working around the legal status of drugs.

These so-called designer drugs are substances that have effects that are similar to illicit drugs but have not yet been identified as such, so drug dealers can get away with selling them, and even marketing them as "legal highs."

Yet it is considered to be highly risky to take, and, as with other drugs, it is just a matter of time before the authorities recognize the risks of such a drug, and take action to protect the public from such high-risk drugs.

In 2014, W-18 was added to the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) list of New Psychoactive Substances.

In 2016, the government of Canada posted a notice online, informing interested parties of a proposal to schedule W-18 as well as its salts, derivatives, isomers, and analogs, and salts of derivatives, isomers, and analogs under the Controlled Drugs and Substances Act, and its regulations.

4 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. MedlinePlus. Opioid addiction.

  2. Webster LR. Risk Factors for Opioid-Use Disorder and Overdose. Anesth Analg. 2017;125(5):1741-1748. doi:10.1213/ANE.0000000000002496

  3. Sustkova M. Synthetic Opioids, (re)Emerging problem in Europe and North America. Int J Emerg Ment Health. 2015;17(4):694-695.

  4. Alberta Health Services. W-Series Drugs - Backgrounder.

Additional Reading

By Elizabeth Hartney, BSc, MSc, MA, PhD
Elizabeth Hartney, BSc, MSc, MA, PhD is a psychologist, professor, and Director of the Centre for Health Leadership and Research at Royal Roads University, Canada.