China's State Food and Drug Administration suspended sales of a popular obesity drug over the weekend amid fears its use may increase the risk of heart attacks and strokes.

The active ingredient, known as sibutramine, works by altering chemical messages to a region of the brain that controls food cravings.

At least 15 companies in China produce medicines containing the substance including Chongqing-based Taiji Group, a company listed on both the Shenzhen and Shanghai stock exchanges.

Taiji Group, which voluntarily recalled its diet drug Qumei, said in a statement Saturday that its recall-related losses would top 40 million yuan ($6 million), or 0.8 percent of annual sales.

Sibutramine was first introduced to world markets in 1997 and entered the Chinese market in 2000.

Back in January, the UK's pharmaceutical regulator told doctors to stop prescribing sibutramine. And earlier this month, US drug giant Abbott Laboratories agreed to withdraw its sibutramine-based obesity drug Meridia from the US market.

Calls to several major drug stores in Beijing confirmed that sibutramine-based medicines were taken off store shelves as early as last week.

Consumers should be able to return unopened containers to the place of purchase for a full refund. The medicine was sold in China both by prescription and over the counter at drug stores.

Hu Yin, deputy secretary-general of China Pharmaceutical Association, told the Global Times that weight-loss drugs often prove to be a headache for the pharmaceutical industry.

"The sector needs additional regulations to guarantee the quality of these medicines … and the public often lacks knowledge about weight-loss drugs, causing them to misuse them," said Hu.

Gao Fei, a Shanghai Pudong Development Bank employee, has been using weight-loss drugs for several years.

On hearing the news of a ban, she told the Global Times she no longer feels diet drugs are safe.

"Those drugs may harm people without them knowing it … I should be more careful about taking weight-loss products in the future," said the 25-year-old woman.