This new street drug is 10,000 times more potent than morphine, and now it’s showing up in Canada and the U.S.

It was first developed in a Canadian lab more than three decades ago, promising and potent — and intended to relieve pain in a less addictive way.

Labeled W-18, the synthetic opioid was the most powerful in a series of about 30 compounds concocted at the University of Alberta and patented in the U.S. and Canada in 1984.