About a year ago, Grace Ainsworth began noticing she was tired all the time. By May, her symptoms had worsened: Her skin had turned a brilliant orange, and the whites of her eyes had taken on a reptilian yellow hue.

Ainsworth's doctor referred her to liver specialist Ken Flora, who ordered several weeks of near-daily blood tests. He concluded that Ainsworth's liver had suffered severe but not irreparable damage from an unlikely source.

In December 2000, she had begun taking the herbal supplement kava for its purportedly relaxing effects. She wasn't alone. Kava has emerged as one of the most popular supplements in the burgeoning herbal market, grossing upwards of $53 million in annual sales. Traditionally used as a stupor-inducing drug in South Pacific Island tribal rituals, kava is marketed in the West as a natural alternative to prescription sedatives such as Valium.

The root of the mature kava plant contains psychoactive chemicals known as kavalactones, which are extracted and put into capsules. Even many Western medical doctors acknowledge that kava works. But increasingly they have also raised concerns about the supplement's safety.

Last November, kava was banned in Germany, Switzerland, France and Britain after a Swiss research group linked the herb to liver damage. In

the United States, kava is now under investigation by the federal Food and Drug Administration.

Upon learning of the concerns about kava, Ainsworth and her husband, Harry, decided to take action. Last month, they contacted Nature's Way, the company that produced the kava she had used. Nature's Way representative Gordon Walker replied that, in the wake of the European ban, "Nature's Way suspended sales of all of our kava products to retailers" in November.

Next, Ainsworth got in touch with Kroger, the parent company of Fred Meyer, where Ainsworth purchased the product. Kroger took a different stance. In response to the Ainsworths' tip, Fred Meyer initially pulled kava off its shelves in late January. One day later, however, Harry Ainsworth noted that the the kava was back--and, he says, marked down to half price.

Although Freddy's declined to comment on its kava policy, the Ainsworths learned of a memo sent out to employees shortly after their temporary recall of the supplement. According to the Ainsworths, the briefing instructs employees that "if a customer wants to know if the kava supplements are safe, please explain to them that there is no evidence that the kava we carry, including the Nature's Way brand, poses any health risk."

The memo continues, claiming that the kava extract sold in Europe is different from that sold in the U.S. QFC, another Kroger-owned retailer, has taken a similar position. "The kava which is sold here in the U.S. is entirely different from that in Europe," says QFC spokesman Dean Olson.

That claim puzzled medical professionals interviewed for this story, who say the most common kava used in both Europe and the U.S. is Piper methysticum, a member of the pepper family. Tori Hudson, a professor at the National College of Naturopathic Medicine, says there may be a difference, however, in the manufacturing process. She says much of the kava sold in Europe is extracted with acetone, whereas most American brands are produced by alcohol extraction. Hudson adds that acetone ingestion has been linked to liver damage.

However, Dr. Atif Zaman, a liver specialist at Oregon Health and Science University, says the Swiss research group that linked kava to liver damage did not mention acetone. And Monica Revelle of the FDA told WW that feds have no information to suggest that the kava sold in Europe is different from that in the U.S.

For Ainsworth (who was taking alcohol-extracted kava), some mild symptoms of her liver damage still linger. She and her husband plan to continue warning others of the risks associated with taking kava. "Our main goal," says Harry Ainsworth, "has been to have these companies at least inform the public of the danger of this supplement."