The stickers or stamps look like pieces of paper, but the paper is coated with the highly toxic drug fentanyl, which more often than not leads to a fatal overdose.
If put in someone's mouth, it could mimic the effects of heroin.
The stickers recently popped up nearby, in West Virginia, and could be deadly if children get hold of them.
There are concerns they're already in western Pennsylvania.
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Au'Driana Cohen, 1, recently became the face of the accidental overdose.
Police say she overdosed on carfentanil, a drug used to tranquilize elephants, in a McKees Rocks home in August. Investigators are still trying to determine how the drug got into her system.
That's what so scary about this latest batch of drugs, said Mike Lynch, the medical director of the Pittsburgh Poison Center at UPMC.
The drug can just be lying around, not looking like a traditional narcotic.
[ RELATED STORY: Baby dies from carfentanil toxicity ]
"It can end up infused on this paper or stickers and then end up in the mouth or other mucus membranes, where you absorb the drugs," Lynch said.
The latest way users can get fentanyl into their system is through paper, such as stamps and stickers.
"What they do is dip it and absorb fentanyl into the paper that then dries," Lynch said.
Once ingested, the drug has the same effect as shooting heroin that's laced with fentanyl, although these stamps and stickers can be even more deadly.
"You don't know the dose because it's not very well-marked out. You don't know how much will be absorbed," he said.
Authorities had their first confirmed case of fentanyl-coated stickers earlier this year in Parkersburg, West Virginia.
Lynch says no local cases have been called in to the Pittsburgh Poison Center, but that doesn't mean it's not happening here.
"I am concerned that it could be around and we're just not aware of it and if it isn't, that it could be at any time," Lynch said.
Parents need to be aware of these stickers and look for them at home, especially if they have teenagers, according to Lynch.