It was a perfect June day for a picnic, warm and sunny, when Rosalie Talbert stumbled to the side of the volleyball court and sat down hard on a bench. During a casual game with family and coworkers, the 34-year-old mother of four had suddenly felt woozy and was having triple vision just as she was getting ready to hit the ball. Her husband, Dan, and her two sisters rushed her to the car. The nearest hospital was about 30 miles away, in Anchorage, Alaska, and Dan screamed in frustration as he swerved around slower cars. Talbert held tight to one sister's hand as she slumped down in the seat. "They didn't think I was conscious because I couldn't talk," she recalls. "So I'd squeeze her hand to let her know I was able to hear."

While her symptoms were similar to those associated with stroke, emergency room doctors discounted the notion because Talbert was so young, she recalls. When a CT scan showed no evidence of brain damage, the doctors sent her home, saying she was probably just dehydrated and needed Gatorade. Three days later, however, her symptoms hadn't improved, so Talbert went back to the hospital. After looking at a magnetic resonance image of her brain, doctors told her she had, in fact, suffered a stroke on the volleyball court. She finally knew what had happened but not why. A week's worth of tests was inconclusive. There was no history of stroke in Talbert's family, she worked out regularly and she didn't smoke. Talbert told her doctors she'd been dropping a liquid herbal diet product into her coffee or soda three times a day in an effort to shed 20 pounds, "but the doctors didn't seem to think it mattered," she remembers. Once Talbert's condition stabilized, they again sent her home.

For more than a year, with doctors unable to pinpoint the cause of Talbert's stroke, her family worried that she would suffer another one. (She stopped taking the diet supplement, Amp II Pro Drops, after her episode, in 1995.) She'd rush to the emergency room at the slightest symptom, but each time it was a false alarm. "It was scary," she says. "[Doctors] couldn't guarantee that I wouldn't have another stroke."

Finally, in 1996, Talbert read a magazine article about the risks of diet supplements containing ephedra, also known as ma huang, which cited a U.S. Food and Drug Administration warning that the herb had been associated with stroke, heart attack and even death. She requested more information from the FDA and sent it to her doctor. He looked at the list of symptoms, which matched Talbert's, and said, "I think we've found it," she recalls.

The weight-loss-pill controversy

Talbert, who at times still suffers from distorted vision a full seven years after her stroke, was outraged: "I took something that was called