City residents are being warned to watch out for a cheap substitute that some unscrupulous dealers are passing off as a prized and expensive fungus that plays an important role in traditional Chinese medicine.

Officials from the Shanghai Food and Drug Administration are now conducting a one-week check of the local market for fake dongchong xiacao, a fungus that grows on certain plants. Some Chinese believe the fungus is a tonic that is good for the kidneys and immune system.

All supermarkets, drug stores, food stores and drug wholesale markets are being covered in the inspection.

FDA officials are on the lookout for a cheap fungus similar to dongchong xiacao in appearance and used by dishonest dealers to cheat customers.

The cheap fungus is not only ineffective as a TCM drug, long-term use can result in side effects such as nausea and chest discomfort, authorities said.

"We received dozens of samples of dongchong xiacao sent by local residents for analysis this year. All the samples were cheap-fungus substitutes," said Wu Zhaoyun of the Shanghai Institute for Food and Drug Control's herbal medicine department.

"There was a bumper crop of the cheap fungus this year. We believe a majority of these products will flow into local market for high profits."

According to officials from Tonghanchun, a leading herbal medicine store, real dongchong xiacao sells for 180 yuan (US$26) to 190 yuan a gram, and up to 350 yuan for the highest quality. The cost of the cheaper substitute is only 2 yuan.

"That's why sellers mix fake fungi or small bamboo sticks into real dongchong xiacao, or make counterfeits using similar materials to cheat customers," said Wang Youzhi, director of the Shanghai FDA's inspection department. "It is difficult for ordinary people to tell the difference."

Since dongchong xiacao sellers don't need a special license, many drug stores, tonic markets and supermarkets sell the product.

"We suggest customers buy it at well-known traditional Chinese medicine stores like Tonghanchun or Caitongde," Wang said. "People also can send samples for analysis to our institute or those drug stores if they buy dongchong xiacao from other provinces or receive it as gift."

(Shanghai Daily September 19, 2008)