The Drug Enforcement Administration reports that the United States is in the midst of a fentanyl crisis, as traffickers are flooding the drug market with counterfeit prescription drugs containing fentanyl, an extremely powerful opioid. These pills, which look like legitimate prescription pain relievers or sedatives, are causing large numbers of fatal overdoses in many parts of the country. Because of its high potency, fentanyl is deadly in very small doses; it is even hazardous for law enforcement, as a lethal dose can be accidentally inhaled or absorbed through skin contact. For more information, see the DEA report - Counterfeit Prescription Pills Containing Fentanyls: A Global Threat (PDF, 3.1MB).
Media reports and official alerts in several U.S. communities (including Sacramento, CA and most recently, Carroll County, MD) are warning of counterfeit pain and anxiety medications that actually contain fentanyl, an extremely powerful, potentially deadly opioid. The pills, which are disguised as common prescription drugs like Norco (hydrocodone), Percocet (oxycodone), and Xanax (alprazolam), are responsible for a growing number of overdose deaths and non-fatal overdoses around the country. Fentanyl is 25 to 50 times stronger than heroin, so even a small amount can cause an overdose. (The Drug Enforcement Administration reports that some of these pills are manufactured in China and smuggled into the U.S. via Mexican drug cartels.)
The fake pills are much cheaper than the real versions. The public should be aware that drugs obtained on the street, even though they look like a real prescription pharmaceutical, may be deadly. It is always unsafe to take a prescription drug unless it comes from your own prescription and is dispensed by a reputable pharmacy.