Fentanyl is ravaging British Columbia. A synthetic opioid developed in the 1950s, clandestine drug labs have brought the drug to Canada’s streets and elsewhere. It’s powerful – the National Institute on Drug Abuse estimates fentanyl is 50 to 100 times stronger than morphine. And the BC Coroners Service reports that it’s connected to nearly half of the 250 drug overdoses reported in the province as of May.

The drug’s reach also extends to the United States. Earlier this month, fentanyl sold as cocaine killed two and hospitalized over a dozen drug users in New Haven, Connecticut. It’s also been involved in high-profile deaths.

Now imagine a drug estimated to be 100 times stronger than fentanyl. It’s called W-18, and it’s showing up in laboratories and drug markets more often. Although W-18 hasn’t been implicated in nearly as many deaths as fentanyl, its strength may one day make it as much of a scourge.

What is W-18?

Researchers at the University of Alberta first synthesized W-18 over 30 years ago in order to create a powerful – yet less addictive – painkiller. First patented in Canada and the U.S. in 1984, Canadian public health agency Health Canada reports the drug was first seen in use as a recreational drug in Europe in 2013. To date, little is known about the drug.

“We have no idea what this chemical does to people, except that it doesn’t seem to work in the same way as morphine, fentanyl and other opioids,” said David Juurlink, M.D., a University of Toronto professor.

That unknown quality may be contributing to the legal limbo in which W-18 seems to exist. Although often compared to synthesized opiates like fentanyl, W-18 itself is not an opioid and until recently was not grouped under Canada’s Controlled Drugs and Substances Act. The Washington Post reports W-18 is currently legal in the U.S.

A possible overreaction?

Some experts are casting doubt on W-18, calling its strength and availability into question. Bryan Roth, M.D., a professor of pharmacology at the University of North Carolina, cautioned the Calgary Herald that much was still unknown about the drug. “It could be a dangerous drug. We don’t know,” Roth told the Herald. “As far as I have been able to determine, there’s no scientific data on the compound, other than [its] single patent. And in the patent, it’s really impossible to determine much about the compound, other than that it has pain-reducing activity and it is more potent than morphine.”

An increasing street presence

Late last year, law enforcement in Alberta found and seized 4 kilograms (around 9 pounds) of an unidentified white powder from an underground drug lab. Months later, Health Canada identified the powder as W-18 and issued a warning. Despite the gap between seizure and identification, the powder had yet to be turned into a form for street sale. That wasn’t the case in August, when law enforcement seized a random assortment of 20 pills from a house near Calgary. A drug analysis later revealed three of the pills contained W-18.

The drug has also shown up in the U.S. In March, Adolphe Joseph, a drug smuggler in Florida’s Broward County, was sentenced to 10 years for smuggling fentanyl he had shipped from China. However, during a search of Joseph’s house, over 2.5 pounds of W-18 was also found.

Drug trends can be volatile

Although alarm over potentially dangerous drugs like W-18 is warranted, it may be wise to consider the history of over street drugs. Last year, the drug flakka was a regular presence in the media. These days, flakka’s hard to find in South Florida, a former hotbed for the drug. CNN recently reported a new ban in China on flakka’s active ingredient helped dry up the supply. As bad as W-18 may sound, it may simply sizzle out the way flakka did.