Fentanyl shows up where people don't expect it. It gets pressed into counterfeit pills made to look like oxycodone or Xanax, and it gets mixed into heroin, cocaine, and other street drugs, which means someone can take it without ever knowing it was there. That is what makes it so dangerous. Knowing the signs of fentanyl use, in yourself or in someone close to you, gives you a real chance to step in before an overdose happens. Early recognition saves lives.