Fentanyl
Fentanyl is a potent opioid used by doctors to treat pain and induce anesthesia during surgery. But it is also produced and sold illegally, sometimes in combination with or under the name of other prescription medications such as OxyContin and Adderall. This kind of contamination, along with its potency, makes fentanyl extraordinarily dangerous and one of the most common drugs involved in overdose deaths today.