In February 2008, hospitals across the United States began seeing something that almost never happens with heparin, a blood thinner used in millions of procedures every year: patients going into sudden, severe allergic-type reactions — hypotension, nausea, shortness of breath — within minutes of receiving it. The FDA would eventually trace the cause to a contaminant called oversulfated chondroitin sulfate, added somewhere upstream in the crude heparin supply chain in China, a
