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In the United States, PPA is no longer sold without a prescription due to a somewhat increased risk of stroke in younger women. In Europe it is either only available by prescription or completely withdrawn from the market. In Canada this drug ingredient was withdrawn from the market on May 31, 2001. [2]
A scientific study[3] found an increased risk of hemorrhagic stroke in women who used phenylpropanolamine, although it is not clear which isomer is to blame. A study at the Yale University School of Medicine in 1999 had produced similar results.[1] Reports of cases of hemorrhagic strokes in PPA users had been circulating since the 1970s.
In November 2000, the Food and Drug Administration (FDA) issued a public health advisory[6] against the use of the drug. In this advisory, the FDA requested that all drug companies discontinue marketing products containing phenylpropanolamine. The agency estimates that PPA caused between 200 and 500 strokes a year among 18-to-49-year-old users.