Wisconsin farmer Butch Weege has never met Sun Dan, a 34-year-old makeup artist who lives in Beijing, but his business depends largely on affluent Chinese like her who take ginseng grown in his state to cope with their hectic urban lives.

Tons of Chinese exports, from computers to catfish and cashmere, are shipped west every year, but Wisconsin ginseng goes the other way, flowing against that mighty tide of trade. U.S. ginseng growers rely almost exclusively on sales to China, and after years of declining profits due to new competition from Canadian and Chinese farmers, those in Wisconsin are defending their brand and hoping to tap a growing Chinese middle-class market.

Ginseng is prized in China, Korea and other Asian countries by consumers who say the bitter root, typically sipped as tea or added to soups, eases stress, fatigue and insomnia.

At a bustling pharmacy in downtown Beijing, Sun is bundled against the December cold in a fashionable down parka and leather boots. She says she steeps slices of the root in hot water and sips the brew when she's anxious or can't sleep.

"It tastes kind of bitter but also sweet," she said. "I don't take it all the time, just when I think of it, and it seems to work. I often feel better the next day."

Wu Miao, a 22-year-old journalism student, said his parents bought him a bottle of pre-cut ginseng root he likes to steep in grain alcohol. He takes a shot in the evening to help him relax before bed.

Neither customer knew where their ginseng came from and neither had heard of Wisconsin. That's a challenge for U.S. farmers trying to build and protect their brand from the other side of the globe.

"Half a world away you can't get out and police individual shops, check their records, make sure it's Wisconsin ginseng going into those packages," said Kirk Baumann, the director of the Ginseng Board of Wisconsin. "It's just overwhelming."

Once the market leaders, Wisconsin ginseng farmers are battling Chinese counterfeiters who slap the Wisconsin seal on inferior ginseng to boost its price. They've also had to fight the perception that Canadian and Chinese ginseng are of equal quality, even though they're often tainted with pesticide residue.

For mild ailments and everyday use, most Chinese request "Xiyang shen" or "Western ginseng," but this is a catchall category that includes Wisconsin root, Canadian imports and varieties of North American ginseng now cultivated in China.

Bottles crammed with nickel-sized slices of so-called Western ginseng line the shelves of specialty pharmacies in Beijing, selling for about 300 yuan ($44) apiece.