Phenylpropanolamine (PPA), a chemical cousin of ephedra, has garnered its fair share of negative publicity. PPA, a common ingredient in over-the-counter cold remedies and diet pills, appears to be linked with an increased risk of stroke. The first reports linking PPA with intracranial hemorrhage, or stroke, involved diet pills formulated with both PPA and caffeine. The FDA banned products containing both PPA and caffeine in1983. However, doctors continued to report some cases of stroke, which occurred after patients had taken products containing PPA. In fact, more than 30 strokes were reported in persons taking PPA since 1979. The majority of these reports involved PPA in diet pills, but a few reports involved PPA in cough and cold medicines. Many of the affected persons were young women between the ages of 17 and 45.

In 1992, both the FDA and manufacturers of products containing PPA recommended an epidemiological...