Guangzhou Baiyunshan's Banlangen granule Photo: CFP

Sales of a Chinese herbal medicine soared over the weekend after a top Chinese respiratory expert reportedly backed the drug in the treatment of the coronavirus.

Banlangen granules, a common Traditional Chinese Medicine (TCM) used to treat colds, sold out in many cities across China over the weekend after top respiratory disease expert Zhong Nanshan said it might be able to inhibit the coronavirus.

The Global Times visited several pharmacies in Shanghai on Monday and found the drug had sold out. 

"Certain types, including those made by Baiyunshan Pharmaceutical, have been out of stock since Saturday. We will have some new stock in tomorrow," an employee at LBX Pharmacy told the Global Times on Monday.

Online research also showed that some brands were "out of stock and the goods will be shipped after arrival," according to multiple online platforms such as JD Pharmacy and Alibaba Health.

Sales of banlangen surged starting on Friday, seeing a one-day rise of 3,130 percent compared with Thursday, according to sales data sent by drug retailer 111 Inc to the Global Times on Monday. 

In a spillover effect, similar TCM products such as Lianhua Qingwen increased by 10 times compared with the same period last year on the platform.

The surging popularity of the medicine comes after a research team led by Zhong found that banlangen granules manufactured by Guangzhou Baiyunshan Pharmaceutical were effective against the virus in a series of in-vitro studies, Chinese media quoted him as saying during a press conference on October 13 in Guangzhou, South China's Guangdong Province.

The company issued an announcement on Sunday saying that media reports regarding the efficacy of the drug only reflect results from a series of in-vitro studies, and further clinical trials are needed to establish the drug's efficacy. 

The sales of Banlangen granules are not expected to have a significant impact on the company's operating results, the statement said.

Shares of Guangzhou Baiyunshan Pharmaceutical Holdings closed down 3.28 percent at 33.06 yuan ($4.93) on Monday in Shanghai. The shares rose by the 10-percent daily limit on Friday.

TCM has been widely used to treat the coronavirus in China. During the outbreak, people rushed to pharmacies to buy Shuanghuanglian oral liquid and Lianhua Qingwen capsules after they were also reported to be effective against the disease.