Of all drugs taken by Americans, 40% come from overseas and, of active ingredients, almost 80% come primarily from China and India, but other nations as well.
Source:
http://www.cnn.com/2012/02/01/opinion/dingell-drug-oversight/index.html
“Of the 1,154 pharmaceutical plants mentioned in generic drug applications to the Food and Drug Administration in 2007, only 13 percent were in the United States. Forty-three percent were in China, and 39 percent in India.”
“One government database lists nearly 3,000 overseas drug plants that export to the United States; the other lists 6,800 plants. Nobody knows which is right.” It seems “”Pharmaceutical companies do not like to reveal where their sources are” for fear that competitors will steal their suppliers….”
SOURCE: From a 2009 NYT article by Gardiner Harris