Comment by sergers

Drugs are being cut with synthetic opiodes, so potent that literally an extra flake in your drug of choice will kill you, unbeknownst to the end user.

This affects junkies to occasional/recreational drug users.

Not sure about the US, but there has been significant overdoses and fatalities relating to fentanyl and other related.

It's a word of caution, you don't know what's in your drugs, it can kill you more than ever.