Mexican pharmacies are selling pills laced with deadly fentanyl to U.S. travelers

Testing on an Adderall pill from Cabo San Lucas, Mexico, came back positive in January. Pharmacies there are selling counterfeit prescription pills laced with illicit substances and passing them off as legitimate pharmaceuticals. (Wally Skalij/Los Angeles Times via Getty Images)

Mexican pharmacies that cater to U.S. tourists are selling medications that appear safe but are frequently laced with deadly fentanyl and methamphetamine.

That's the conclusion of new research that examined medications purchased legally in four cities in northern Mexico where travelers from the U.S. often seek low-cost health care and pharmaceuticals.